1Config(3pm)            Perl Programmers Reference Guide            Config(3pm)
2
3
4

NAME

6       Config - access Perl configuration information
7

SYNOPSIS

9           use Config;
10           if ($Config{usethreads}) {
11               print "has thread support\n"
12           }
13
14           use Config qw(myconfig config_sh config_vars config_re);
15
16           print myconfig();
17
18           print config_sh();
19
20           print config_re();
21
22           config_vars(qw(osname archname));
23

DESCRIPTION

25       The Config module contains all the information that was available to
26       the "Configure" program at Perl build time (over 900 values).
27
28       Shell variables from the config.sh file (written by Configure) are
29       stored in the readonly-variable %Config, indexed by their names.
30
31       Values stored in config.sh as 'undef' are returned as undefined values.
32       The perl "exists" function can be used to check if a named variable
33       exists.
34
35       For a description of the variables, please have a look at the Glossary
36       file, as written in the Porting folder, or use the url:
37       http://perl5.git.perl.org/perl.git/blob/HEAD:/Porting/Glossary
38
39       myconfig()
40           Returns a textual summary of the major perl configuration values.
41           See also "-V" in "Switches" in perlrun.
42
43       config_sh()
44           Returns the entire perl configuration information in the form of
45           the original config.sh shell variable assignment script.
46
47       config_re($regex)
48           Like config_sh() but returns, as a list, only the config entries
49           who's names match the $regex.
50
51       config_vars(@names)
52           Prints to STDOUT the values of the named configuration variable.
53           Each is printed on a separate line in the form:
54
55             name='value';
56
57           Names which are unknown are output as "name='UNKNOWN';".  See also
58           "-V:name" in "Switches" in perlrun.
59

EXAMPLE

61       Here's a more sophisticated example of using %Config:
62
63           use Config;
64           use strict;
65
66           my %sig_num;
67           my @sig_name;
68           unless($Config{sig_name} && $Config{sig_num}) {
69               die "No sigs?";
70           } else {
71               my @names = split ' ', $Config{sig_name};
72               @sig_num{@names} = split ' ', $Config{sig_num};
73               foreach (@names) {
74                   $sig_name[$sig_num{$_}] ||= $_;
75               }
76           }
77
78           print "signal #17 = $sig_name[17]\n";
79           if ($sig_num{ALRM}) {
80               print "SIGALRM is $sig_num{ALRM}\n";
81           }
82

WARNING

84       Because this information is not stored within the perl executable
85       itself it is possible (but unlikely) that the information does not
86       relate to the actual perl binary which is being used to access it.
87
88       The Config module is installed into the architecture and version
89       specific library directory ($Config{installarchlib}) and it checks the
90       perl version number when loaded.
91
92       The values stored in config.sh may be either single-quoted or double-
93       quoted. Double-quoted strings are handy for those cases where you need
94       to include escape sequences in the strings. To avoid runtime variable
95       interpolation, any "$" and "@" characters are replaced by "\$" and
96       "\@", respectively. This isn't foolproof, of course, so don't embed
97       "\$" or "\@" in double-quoted strings unless you're willing to deal
98       with the consequences. (The slashes will end up escaped and the "$" or
99       "@" will trigger variable interpolation)
100

GLOSSARY

102       Most "Config" variables are determined by the "Configure" script on
103       platforms supported by it (which is most UNIX platforms).  Some
104       platforms have custom-made "Config" variables, and may thus not have
105       some of the variables described below, or may have extraneous variables
106       specific to that particular port.  See the port specific documentation
107       in such cases.
108
109   _
110       "_a"
111           From Unix.U:
112
113           This variable defines the extension used for ordinary library
114           files.  For unix, it is .a.  The . is included.  Other possible
115           values include .lib.
116
117       "_exe"
118           From Unix.U:
119
120           This variable defines the extension used for executable files.
121           "DJGPP", Cygwin and OS/2 use .exe.  Stratus "VOS" uses .pm.  On
122           operating systems which do not require a specific extension for
123           executable files, this variable is empty.
124
125       "_o"
126           From Unix.U:
127
128           This variable defines the extension used for object files.  For
129           unix, it is .o.  The . is included.  Other possible values include
130           .obj.
131
132   a
133       "afs"
134           From afs.U:
135
136           This variable is set to "true" if "AFS" (Andrew File System) is
137           used on the system, "false" otherwise.  It is possible to override
138           this with a hint value or command line option, but you'd better
139           know what you are doing.
140
141       "afsroot"
142           From afs.U:
143
144           This variable is by default set to /afs. In the unlikely case this
145           is not the correct root, it is possible to override this with a
146           hint value or command line option.  This will be used in subsequent
147           tests for AFSness in the configure and test process.
148
149       "alignbytes"
150           From alignbytes.U:
151
152           This variable holds the number of bytes required to align a
153           double-- or a long double when applicable. Usual values are 2, 4
154           and 8.  The default is eight, for safety.
155
156       "ansi2knr"
157           From ansi2knr.U:
158
159           This variable is set if the user needs to run ansi2knr.  Currently,
160           this is not supported, so we just abort.
161
162       "aphostname"
163           From d_gethname.U:
164
165           This variable contains the command which can be used to compute the
166           host name. The command is fully qualified by its absolute path, to
167           make it safe when used by a process with super-user privileges.
168
169       "api_revision"
170           From patchlevel.U:
171
172           The three variables, api_revision, api_version, and api_subversion,
173           specify the version of the oldest perl binary compatible with the
174           present perl.  In a full version string such as 5.6.1, api_revision
175           is the 5.  Prior to 5.5.640, the format was a floating point
176           number, like 5.00563.
177
178           perl.c:incpush() and lib/lib.pm will automatically search in
179           $sitelib/.. for older directories back to the limit specified by
180           these api_ variables.  This is only useful if you have a perl
181           library directory tree structured like the default one.  See
182           "INSTALL" for how this works.  The versioned site_perl directory
183           was introduced in 5.005, so that is the lowest possible value.  The
184           version list appropriate for the current system is determined in
185           inc_version_list.U.
186
187           "XXX" To do:  Since compatibility can depend on compile time
188           options (such as bincompat, longlong, etc.) it should (perhaps) be
189           set by Configure, but currently it isn't.  Currently, we read a
190           hard-wired value from patchlevel.h.  Perhaps what we ought to do is
191           take the hard-wired value from patchlevel.h but then modify it if
192           the current Configure options warrant.  patchlevel.h then would use
193           an #ifdef guard.
194
195       "api_subversion"
196           From patchlevel.U:
197
198           The three variables, api_revision, api_version, and api_subversion,
199           specify the version of the oldest perl binary compatible with the
200           present perl.  In a full version string such as 5.6.1,
201           api_subversion is the 1.  See api_revision for full details.
202
203       "api_version"
204           From patchlevel.U:
205
206           The three variables, api_revision, api_version, and api_subversion,
207           specify the version of the oldest perl binary compatible with the
208           present perl.  In a full version string such as 5.6.1, api_version
209           is the 6.  See api_revision for full details.  As a special case,
210           5.5.0 is rendered in the old-style as 5.005.  (In the 5.005_0x
211           maintenance series, this was the only versioned directory in
212           $sitelib.)
213
214       "api_versionstring"
215           From patchlevel.U:
216
217           This variable combines api_revision, api_version, and
218           api_subversion in a format such as 5.6.1 (or 5_6_1) suitable for
219           use as a directory name.  This is filesystem dependent.
220
221       "ar"
222           From Loc.U:
223
224           This variable is used internally by Configure to determine the full
225           pathname (if any) of the ar program.  After Configure runs, the
226           value is reset to a plain "ar" and is not useful.
227
228       "archlib"
229           From archlib.U:
230
231           This variable holds the name of the directory in which the user
232           wants to put architecture-dependent public library files for
233           $package.  It is most often a local directory such as
234           /usr/local/lib.  Programs using this variable must be prepared to
235           deal with filename expansion.
236
237       "archlibexp"
238           From archlib.U:
239
240           This variable is the same as the archlib variable, but is filename
241           expanded at configuration time, for convenient use.
242
243       "archname"
244           From archname.U:
245
246           This variable is a short name to characterize the current
247           architecture.  It is used mainly to construct the default archlib.
248
249       "archname64"
250           From use64bits.U:
251
252           This variable is used for the 64-bitness part of $archname.
253
254       "archobjs"
255           From Unix.U:
256
257           This variable defines any additional objects that must be linked in
258           with the program on this architecture.  On unix, it is usually
259           empty.  It is typically used to include emulations of unix calls or
260           other facilities.  For perl on OS/2, for example, this would
261           include os2/os2.obj.
262
263       "asctime_r_proto"
264           From d_asctime_r.U:
265
266           This variable encodes the prototype of asctime_r.  It is zero if
267           d_asctime_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
268           of reentr.h if d_asctime_r is defined.
269
270       "awk"
271           From Loc.U:
272
273           This variable is used internally by Configure to determine the full
274           pathname (if any) of the awk program.  After Configure runs, the
275           value is reset to a plain "awk" and is not useful.
276
277   b
278       "baserev"
279           From baserev.U:
280
281           The base revision level of this package, from the .package file.
282
283       "bash"
284           From Loc.U:
285
286           This variable is defined but not used by Configure.  The value is
287           the empty string and is not useful.
288
289       "bin"
290           From bin.U:
291
292           This variable holds the name of the directory in which the user
293           wants to put publicly executable images for the package in
294           question.  It is most often a local directory such as
295           /usr/local/bin. Programs using this variable must be prepared to
296           deal with ~name substitution.
297
298       "bin_ELF"
299           From dlsrc.U:
300
301           This variable saves the result from configure if generated binaries
302           are in "ELF" format. Only set to defined when the test has actually
303           been performed, and the result was positive.
304
305       "binexp"
306           From bin.U:
307
308           This is the same as the bin variable, but is filename expanded at
309           configuration time, for use in your makefiles.
310
311       "bison"
312           From Loc.U:
313
314           This variable is used internally by Configure to determine the full
315           pathname (if any) of the bison program.  After Configure runs, the
316           value is reset to a plain "bison" and is not useful.
317
318       "byacc"
319           From Loc.U:
320
321           This variable is used internally by Configure to determine the full
322           pathname (if any) of the byacc program.  After Configure runs, the
323           value is reset to a plain "byacc" and is not useful.
324
325       "byteorder"
326           From byteorder.U:
327
328           This variable holds the byte order in a "UV". In the following,
329           larger digits indicate more significance.  The variable byteorder
330           is either 4321 on a big-endian machine, or 1234 on a little-endian,
331           or 87654321 on a Cray ... or 3412 with weird order !
332
333   c
334       "c" From n.U:
335
336           This variable contains the \c string if that is what causes the
337           echo command to suppress newline.  Otherwise it is null.  Correct
338           usage is $echo $n "prompt for a question: $c".
339
340       "castflags"
341           From d_castneg.U:
342
343           This variable contains a flag that precise difficulties the
344           compiler has casting odd floating values to unsigned long: 0 = ok 1
345           = couldn't cast < 0 2 = couldn't cast >= 0x80000000 4 = couldn't
346           cast in argument expression list
347
348       "cat"
349           From Loc.U:
350
351           This variable is used internally by Configure to determine the full
352           pathname (if any) of the cat program.  After Configure runs, the
353           value is reset to a plain "cat" and is not useful.
354
355       "cc"
356           From cc.U:
357
358           This variable holds the name of a command to execute a C compiler
359           which can resolve multiple global references that happen to have
360           the same name.  Usual values are "cc" and "gcc".  Fervent "ANSI"
361           compilers may be called "c89".  "AIX" has xlc.
362
363       "cccdlflags"
364           From dlsrc.U:
365
366           This variable contains any special flags that might need to be
367           passed with "cc -c" to compile modules to be used to create a
368           shared library that will be used for dynamic loading.  For hpux,
369           this should be +z.  It is up to the makefile to use it.
370
371       "ccdlflags"
372           From dlsrc.U:
373
374           This variable contains any special flags that might need to be
375           passed to cc to link with a shared library for dynamic loading.  It
376           is up to the makefile to use it.  For sunos 4.1, it should be
377           empty.
378
379       "ccflags"
380           From ccflags.U:
381
382           This variable contains any additional C compiler flags desired by
383           the user.  It is up to the Makefile to use this.
384
385       "ccflags_uselargefiles"
386           From uselfs.U:
387
388           This variable contains the compiler flags needed by large file
389           builds and added to ccflags by hints files.
390
391       "ccname"
392           From Checkcc.U:
393
394           This can set either by hints files or by Configure.  If using gcc,
395           this is gcc, and if not, usually equal to cc, unimpressive, no?
396           Some platforms, however, make good use of this by storing the
397           flavor of the C compiler being used here.  For example if using the
398           Sun WorkShop suite, ccname will be "workshop".
399
400       "ccsymbols"
401           From Cppsym.U:
402
403           The variable contains the symbols defined by the C compiler alone.
404           The symbols defined by cpp or by cc when it calls cpp are not in
405           this list, see cppsymbols and cppccsymbols.  The list is a space-
406           separated list of symbol=value tokens.
407
408       "ccversion"
409           From Checkcc.U:
410
411           This can set either by hints files or by Configure.  If using a
412           (non-gcc) vendor cc, this variable may contain a version for the
413           compiler.
414
415       "cf_by"
416           From cf_who.U:
417
418           Login name of the person who ran the Configure script and answered
419           the questions. This is used to tag both config.sh and config_h.SH.
420
421       "cf_email"
422           From cf_email.U:
423
424           Electronic mail address of the person who ran Configure. This can
425           be used by units that require the user's e-mail, like MailList.U.
426
427       "cf_time"
428           From cf_who.U:
429
430           Holds the output of the "date" command when the configuration file
431           was produced. This is used to tag both config.sh and config_h.SH.
432
433       "charbits"
434           From charsize.U:
435
436           This variable contains the value of the "CHARBITS" symbol, which
437           indicates to the C program how many bits there are in a character.
438
439       "charsize"
440           From charsize.U:
441
442           This variable contains the value of the "CHARSIZE" symbol, which
443           indicates to the C program how many bytes there are in a character.
444
445       "chgrp"
446           From Loc.U:
447
448           This variable is defined but not used by Configure.  The value is
449           the empty string and is not useful.
450
451       "chmod"
452           From Loc.U:
453
454           This variable is used internally by Configure to determine the full
455           pathname (if any) of the chmod program.  After Configure runs, the
456           value is reset to a plain "chmod" and is not useful.
457
458       "chown"
459           From Loc.U:
460
461           This variable is defined but not used by Configure.  The value is
462           the empty string and is not useful.
463
464       "clocktype"
465           From d_times.U:
466
467           This variable holds the type returned by times(). It can be long,
468           or clock_t on "BSD" sites (in which case <sys/types.h> should be
469           included).
470
471       "comm"
472           From Loc.U:
473
474           This variable is used internally by Configure to determine the full
475           pathname (if any) of the comm program.  After Configure runs, the
476           value is reset to a plain "comm" and is not useful.
477
478       "compress"
479           From Loc.U:
480
481           This variable is defined but not used by Configure.  The value is
482           the empty string and is not useful.
483
484       "config_arg0"
485           From Options.U:
486
487           This variable contains the string used to invoke the Configure
488           command, as reported by the shell in the $0 variable.
489
490       "config_argc"
491           From Options.U:
492
493           This variable countains the number of command-line arguments passed
494           to Configure, as reported by the shell in the $# variable.  The
495           individual arguments are stored as variables config_argc1,
496           config_argc2, etc.
497
498       "config_args"
499           From Options.U:
500
501           This variable contains a single string giving the command-line
502           arguments passed to Configure. Spaces within arguments, quotes, and
503           escaped characters are not correctly preserved.  To reconstruct the
504           command line, you must assemble the individual command line pieces,
505           given in config_arg[0-9]*.
506
507       "contains"
508           From contains.U:
509
510           This variable holds the command to do a grep with a proper return
511           status.  On most sane systems it is simply "grep".  On insane
512           systems it is a grep followed by a cat followed by a test.  This
513           variable is primarily for the use of other Configure units.
514
515       "cp"
516           From Loc.U:
517
518           This variable is used internally by Configure to determine the full
519           pathname (if any) of the cp program.  After Configure runs, the
520           value is reset to a plain "cp" and is not useful.
521
522       "cpio"
523           From Loc.U:
524
525           This variable is defined but not used by Configure.  The value is
526           the empty string and is not useful.
527
528       "cpp"
529           From Loc.U:
530
531           This variable is used internally by Configure to determine the full
532           pathname (if any) of the cpp program.  After Configure runs, the
533           value is reset to a plain "cpp" and is not useful.
534
535       "cpp_stuff"
536           From cpp_stuff.U:
537
538           This variable contains an identification of the concatenation
539           mechanism used by the C preprocessor.
540
541       "cppccsymbols"
542           From Cppsym.U:
543
544           The variable contains the symbols defined by the C compiler when it
545           calls cpp.  The symbols defined by the cc alone or cpp alone are
546           not in this list, see ccsymbols and cppsymbols.  The list is a
547           space-separated list of symbol=value tokens.
548
549       "cppflags"
550           From ccflags.U:
551
552           This variable holds the flags that will be passed to the C pre-
553           processor. It is up to the Makefile to use it.
554
555       "cpplast"
556           From cppstdin.U:
557
558           This variable has the same functionality as cppminus, only it
559           applies to cpprun and not cppstdin.
560
561       "cppminus"
562           From cppstdin.U:
563
564           This variable contains the second part of the string which will
565           invoke the C preprocessor on the standard input and produce to
566           standard output.  This variable will have the value "-" if cppstdin
567           needs a minus to specify standard input, otherwise the value is "".
568
569       "cpprun"
570           From cppstdin.U:
571
572           This variable contains the command which will invoke a C
573           preprocessor on standard input and put the output to stdout. It is
574           guaranteed not to be a wrapper and may be a null string if no
575           preprocessor can be made directly available. This preprocessor
576           might be different from the one used by the C compiler. Don't
577           forget to append cpplast after the preprocessor options.
578
579       "cppstdin"
580           From cppstdin.U:
581
582           This variable contains the command which will invoke the C
583           preprocessor on standard input and put the output to stdout.  It is
584           primarily used by other Configure units that ask about preprocessor
585           symbols.
586
587       "cppsymbols"
588           From Cppsym.U:
589
590           The variable contains the symbols defined by the C preprocessor
591           alone.  The symbols defined by cc or by cc when it calls cpp are
592           not in this list, see ccsymbols and cppccsymbols.  The list is a
593           space-separated list of symbol=value tokens.
594
595       "crypt_r_proto"
596           From d_crypt_r.U:
597
598           This variable encodes the prototype of crypt_r.  It is zero if
599           d_crypt_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
600           of reentr.h if d_crypt_r is defined.
601
602       "cryptlib"
603           From d_crypt.U:
604
605           This variable holds -lcrypt or the path to a libcrypt.a archive if
606           the crypt() function is not defined in the standard C library. It
607           is up to the Makefile to use this.
608
609       "csh"
610           From Loc.U:
611
612           This variable is used internally by Configure to determine the full
613           pathname (if any) of the csh program.  After Configure runs, the
614           value is reset to a plain "csh" and is not useful.
615
616       "ctermid_r_proto"
617           From d_ctermid_r.U:
618
619           This variable encodes the prototype of ctermid_r.  It is zero if
620           d_ctermid_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
621           of reentr.h if d_ctermid_r is defined.
622
623       "ctime_r_proto"
624           From d_ctime_r.U:
625
626           This variable encodes the prototype of ctime_r.  It is zero if
627           d_ctime_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
628           of reentr.h if d_ctime_r is defined.
629
630   d
631       "d__fwalk"
632           From d__fwalk.U:
633
634           This variable conditionally defines "HAS__FWALK" if _fwalk() is
635           available to apply a function to all the file handles.
636
637       "d_access"
638           From d_access.U:
639
640           This variable conditionally defines "HAS_ACCESS" if the access()
641           system call is available to check for access permissions using real
642           IDs.
643
644       "d_accessx"
645           From d_accessx.U:
646
647           This variable conditionally defines the "HAS_ACCESSX" symbol, which
648           indicates to the C program that the accessx() routine is available.
649
650       "d_aintl"
651           From d_aintl.U:
652
653           This variable conditionally defines the "HAS_AINTL" symbol, which
654           indicates to the C program that the aintl() routine is available.
655           If copysignl is also present we can emulate modfl.
656
657       "d_alarm"
658           From d_alarm.U:
659
660           This variable conditionally defines the "HAS_ALARM" symbol, which
661           indicates to the C program that the alarm() routine is available.
662
663       "d_archlib"
664           From archlib.U:
665
666           This variable conditionally defines "ARCHLIB" to hold the pathname
667           of architecture-dependent library files for $package.  If $archlib
668           is the same as $privlib, then this is set to undef.
669
670       "d_asctime64"
671           From d_timefuncs64.U:
672
673           This variable conditionally defines the HAS_ASCTIME64 symbol, which
674           indicates to the C program that the asctime64 () routine is
675           available.
676
677       "d_asctime_r"
678           From d_asctime_r.U:
679
680           This variable conditionally defines the "HAS_ASCTIME_R" symbol,
681           which indicates to the C program that the asctime_r() routine is
682           available.
683
684       "d_atolf"
685           From atolf.U:
686
687           This variable conditionally defines the "HAS_ATOLF" symbol, which
688           indicates to the C program that the atolf() routine is available.
689
690       "d_atoll"
691           From atoll.U:
692
693           This variable conditionally defines the "HAS_ATOLL" symbol, which
694           indicates to the C program that the atoll() routine is available.
695
696       "d_attribute_deprecated"
697           From d_attribut.U:
698
699           This variable conditionally defines "HASATTRIBUTE_DEPRECATED",
700           which indicates that "GCC" can handle the attribute for marking
701           deprecated APIs
702
703       "d_attribute_format"
704           From d_attribut.U:
705
706           This variable conditionally defines "HASATTRIBUTE_FORMAT", which
707           indicates the C compiler can check for printf-like formats.
708
709       "d_attribute_malloc"
710           From d_attribut.U:
711
712           This variable conditionally defines "HASATTRIBUTE_MALLOC", which
713           indicates the C compiler can understand functions as having malloc-
714           like semantics.
715
716       "d_attribute_nonnull"
717           From d_attribut.U:
718
719           This variable conditionally defines "HASATTRIBUTE_NONNULL", which
720           indicates that the C compiler can know that certain arguments must
721           not be "NULL", and will check accordingly at compile time.
722
723       "d_attribute_noreturn"
724           From d_attribut.U:
725
726           This variable conditionally defines "HASATTRIBUTE_NORETURN", which
727           indicates that the C compiler can know that certain functions are
728           guaranteed never to return.
729
730       "d_attribute_pure"
731           From d_attribut.U:
732
733           This variable conditionally defines "HASATTRIBUTE_PURE", which
734           indicates that the C compiler can know that certain functions are
735           "pure" functions, meaning that they have no side effects, and only
736           rely on function input and/or global data for their results.
737
738       "d_attribute_unused"
739           From d_attribut.U:
740
741           This variable conditionally defines "HASATTRIBUTE_UNUSED", which
742           indicates that the C compiler can know that certain variables and
743           arguments may not always be used, and to not throw warnings if they
744           don't get used.
745
746       "d_attribute_warn_unused_result"
747           From d_attribut.U:
748
749           This variable conditionally defines
750           "HASATTRIBUTE_WARN_UNUSED_RESULT", which indicates that the C
751           compiler can know that certain functions have a return values that
752           must not be ignored, such as malloc() or open().
753
754       "d_bcmp"
755           From d_bcmp.U:
756
757           This variable conditionally defines the "HAS_BCMP" symbol if the
758           bcmp() routine is available to compare strings.
759
760       "d_bcopy"
761           From d_bcopy.U:
762
763           This variable conditionally defines the "HAS_BCOPY" symbol if the
764           bcopy() routine is available to copy strings.
765
766       "d_bsd"
767           From Guess.U:
768
769           This symbol conditionally defines the symbol "BSD" when running on
770           a "BSD" system.
771
772       "d_bsdgetpgrp"
773           From d_getpgrp.U:
774
775           This variable conditionally defines "USE_BSD_GETPGRP" if getpgrp
776           needs one arguments whereas "USG" one needs none.
777
778       "d_bsdsetpgrp"
779           From d_setpgrp.U:
780
781           This variable conditionally defines "USE_BSD_SETPGRP" if setpgrp
782           needs two arguments whereas "USG" one needs none.  See also
783           d_setpgid for a "POSIX" interface.
784
785       "d_builtin_choose_expr"
786           From d_builtin.U:
787
788           This conditionally defines "HAS_BUILTIN_CHOOSE_EXPR", which
789           indicates that the compiler supports __builtin_choose_expr(x,y,z).
790           This built-in function is analogous to the "x?y:z" operator in C,
791           except that the expression returned has its type unaltered by
792           promotion rules. Also, the built-in function does not evaluate the
793           expression that was not chosen.
794
795       "d_builtin_expect"
796           From d_builtin.U:
797
798           This conditionally defines "HAS_BUILTIN_EXPECT", which indicates
799           that the compiler supports __builtin_expect(exp,c).  You may use
800           __builtin_expect to provide the compiler with branch prediction
801           information.
802
803       "d_bzero"
804           From d_bzero.U:
805
806           This variable conditionally defines the "HAS_BZERO" symbol if the
807           bzero() routine is available to set memory to 0.
808
809       "d_c99_variadic_macros"
810           From d_c99_variadic.U:
811
812           This variable conditionally defines the HAS_C99_VARIADIC_MACROS
813           symbol, which indicates to the C program that C99 variadic macros
814           are available.
815
816       "d_casti32"
817           From d_casti32.U:
818
819           This variable conditionally defines CASTI32, which indicates
820           whether the C compiler can cast large floats to 32-bit ints.
821
822       "d_castneg"
823           From d_castneg.U:
824
825           This variable conditionally defines "CASTNEG", which indicates
826           wether the C compiler can cast negative float to unsigned.
827
828       "d_charvspr"
829           From d_vprintf.U:
830
831           This variable conditionally defines "CHARVSPRINTF" if this system
832           has vsprintf returning type (char*).  The trend seems to be to
833           declare it as "int vsprintf()".
834
835       "d_chown"
836           From d_chown.U:
837
838           This variable conditionally defines the "HAS_CHOWN" symbol, which
839           indicates to the C program that the chown() routine is available.
840
841       "d_chroot"
842           From d_chroot.U:
843
844           This variable conditionally defines the "HAS_CHROOT" symbol, which
845           indicates to the C program that the chroot() routine is available.
846
847       "d_chsize"
848           From d_chsize.U:
849
850           This variable conditionally defines the "CHSIZE" symbol, which
851           indicates to the C program that the chsize() routine is available
852           to truncate files.  You might need a -lx to get this routine.
853
854       "d_class"
855           From d_class.U:
856
857           This variable conditionally defines the "HAS_CLASS" symbol, which
858           indicates to the C program that the class() routine is available.
859
860       "d_clearenv"
861           From d_clearenv.U:
862
863           This variable conditionally defines the "HAS_CLEARENV" symbol,
864           which indicates to the C program that the clearenv () routine is
865           available.
866
867       "d_closedir"
868           From d_closedir.U:
869
870           This variable conditionally defines "HAS_CLOSEDIR" if closedir() is
871           available.
872
873       "d_cmsghdr_s"
874           From d_cmsghdr_s.U:
875
876           This variable conditionally defines the "HAS_STRUCT_CMSGHDR"
877           symbol, which indicates that the struct cmsghdr is supported.
878
879       "d_const"
880           From d_const.U:
881
882           This variable conditionally defines the "HASCONST" symbol, which
883           indicates to the C program that this C compiler knows about the
884           const type.
885
886       "d_copysignl"
887           From d_copysignl.U:
888
889           This variable conditionally defines the "HAS_COPYSIGNL" symbol,
890           which indicates to the C program that the copysignl() routine is
891           available.  If aintl is also present we can emulate modfl.
892
893       "d_cplusplus"
894           From d_cplusplus.U:
895
896           This variable conditionally defines the "USE_CPLUSPLUS" symbol,
897           which indicates that a C++ compiler was used to compiled Perl and
898           will be used to compile extensions.
899
900       "d_crypt"
901           From d_crypt.U:
902
903           This variable conditionally defines the "CRYPT" symbol, which
904           indicates to the C program that the crypt() routine is available to
905           encrypt passwords and the like.
906
907       "d_crypt_r"
908           From d_crypt_r.U:
909
910           This variable conditionally defines the "HAS_CRYPT_R" symbol, which
911           indicates to the C program that the crypt_r() routine is available.
912
913       "d_csh"
914           From d_csh.U:
915
916           This variable conditionally defines the "CSH" symbol, which
917           indicates to the C program that the C-shell exists.
918
919       "d_ctermid"
920           From d_ctermid.U:
921
922           This variable conditionally defines "CTERMID" if ctermid() is
923           available to generate filename for terminal.
924
925       "d_ctermid_r"
926           From d_ctermid_r.U:
927
928           This variable conditionally defines the "HAS_CTERMID_R" symbol,
929           which indicates to the C program that the ctermid_r() routine is
930           available.
931
932       "d_ctime64"
933           From d_timefuncs64.U:
934
935           This variable conditionally defines the HAS_CTIME64 symbol, which
936           indicates to the C program that the ctime64 () routine is
937           available.
938
939       "d_ctime_r"
940           From d_ctime_r.U:
941
942           This variable conditionally defines the "HAS_CTIME_R" symbol, which
943           indicates to the C program that the ctime_r() routine is available.
944
945       "d_cuserid"
946           From d_cuserid.U:
947
948           This variable conditionally defines the "HAS_CUSERID" symbol, which
949           indicates to the C program that the cuserid() routine is available
950           to get character login names.
951
952       "d_dbl_dig"
953           From d_dbl_dig.U:
954
955           This variable conditionally defines d_dbl_dig if this system's
956           header files provide "DBL_DIG", which is the number of significant
957           digits in a double precision number.
958
959       "d_dbminitproto"
960           From d_dbminitproto.U:
961
962           This variable conditionally defines the "HAS_DBMINIT_PROTO" symbol,
963           which indicates to the C program that the system provides a
964           prototype for the dbminit() function.  Otherwise, it is up to the
965           program to supply one.
966
967       "d_difftime"
968           From d_difftime.U:
969
970           This variable conditionally defines the "HAS_DIFFTIME" symbol,
971           which indicates to the C program that the difftime() routine is
972           available.
973
974       "d_difftime64"
975           From d_timefuncs64.U:
976
977           This variable conditionally defines the HAS_DIFFTIME64 symbol,
978           which indicates to the C program that the difftime64 () routine is
979           available.
980
981       "d_dir_dd_fd"
982           From d_dir_dd_fd.U:
983
984           This variable conditionally defines the "HAS_DIR_DD_FD" symbol,
985           which indicates that the "DIR" directory stream type contains a
986           member variable called dd_fd.
987
988       "d_dirfd"
989           From d_dirfd.U:
990
991           This variable conditionally defines the "HAS_DIRFD" constant, which
992           indicates to the C program that dirfd() is available to return the
993           file descriptor of a directory stream.
994
995       "d_dirnamlen"
996           From i_dirent.U:
997
998           This variable conditionally defines "DIRNAMLEN", which indicates to
999           the C program that the length of directory entry names is provided
1000           by a d_namelen field.
1001
1002       "d_dlerror"
1003           From d_dlerror.U:
1004
1005           This variable conditionally defines the "HAS_DLERROR" symbol, which
1006           indicates to the C program that the dlerror() routine is available.
1007
1008       "d_dlopen"
1009           From d_dlopen.U:
1010
1011           This variable conditionally defines the "HAS_DLOPEN" symbol, which
1012           indicates to the C program that the dlopen() routine is available.
1013
1014       "d_dlsymun"
1015           From d_dlsymun.U:
1016
1017           This variable conditionally defines "DLSYM_NEEDS_UNDERSCORE", which
1018           indicates that we need to prepend an underscore to the symbol name
1019           before calling dlsym().
1020
1021       "d_dosuid"
1022           From d_dosuid.U:
1023
1024           This variable conditionally defines the symbol "DOSUID", which
1025           tells the C program that it should insert setuid emulation code on
1026           hosts which have setuid #! scripts disabled.
1027
1028       "d_drand48_r"
1029           From d_drand48_r.U:
1030
1031           This variable conditionally defines the HAS_DRAND48_R symbol, which
1032           indicates to the C program that the drand48_r() routine is
1033           available.
1034
1035       "d_drand48proto"
1036           From d_drand48proto.U:
1037
1038           This variable conditionally defines the HAS_DRAND48_PROTO symbol,
1039           which indicates to the C program that the system provides a
1040           prototype for the drand48() function.  Otherwise, it is up to the
1041           program to supply one.
1042
1043       "d_dup2"
1044           From d_dup2.U:
1045
1046           This variable conditionally defines HAS_DUP2 if dup2() is available
1047           to duplicate file descriptors.
1048
1049       "d_eaccess"
1050           From d_eaccess.U:
1051
1052           This variable conditionally defines the "HAS_EACCESS" symbol, which
1053           indicates to the C program that the eaccess() routine is available.
1054
1055       "d_endgrent"
1056           From d_endgrent.U:
1057
1058           This variable conditionally defines the "HAS_ENDGRENT" symbol,
1059           which indicates to the C program that the endgrent() routine is
1060           available for sequential access of the group database.
1061
1062       "d_endgrent_r"
1063           From d_endgrent_r.U:
1064
1065           This variable conditionally defines the "HAS_ENDGRENT_R" symbol,
1066           which indicates to the C program that the endgrent_r() routine is
1067           available.
1068
1069       "d_endhent"
1070           From d_endhent.U:
1071
1072           This variable conditionally defines "HAS_ENDHOSTENT" if
1073           endhostent() is available to close whatever was being used for host
1074           queries.
1075
1076       "d_endhostent_r"
1077           From d_endhostent_r.U:
1078
1079           This variable conditionally defines the "HAS_ENDHOSTENT_R" symbol,
1080           which indicates to the C program that the endhostent_r() routine is
1081           available.
1082
1083       "d_endnent"
1084           From d_endnent.U:
1085
1086           This variable conditionally defines "HAS_ENDNETENT" if endnetent()
1087           is available to close whatever was being used for network queries.
1088
1089       "d_endnetent_r"
1090           From d_endnetent_r.U:
1091
1092           This variable conditionally defines the "HAS_ENDNETENT_R" symbol,
1093           which indicates to the C program that the endnetent_r() routine is
1094           available.
1095
1096       "d_endpent"
1097           From d_endpent.U:
1098
1099           This variable conditionally defines "HAS_ENDPROTOENT" if
1100           endprotoent() is available to close whatever was being used for
1101           protocol queries.
1102
1103       "d_endprotoent_r"
1104           From d_endprotoent_r.U:
1105
1106           This variable conditionally defines the "HAS_ENDPROTOENT_R" symbol,
1107           which indicates to the C program that the endprotoent_r() routine
1108           is available.
1109
1110       "d_endpwent"
1111           From d_endpwent.U:
1112
1113           This variable conditionally defines the "HAS_ENDPWENT" symbol,
1114           which indicates to the C program that the endpwent() routine is
1115           available for sequential access of the passwd database.
1116
1117       "d_endpwent_r"
1118           From d_endpwent_r.U:
1119
1120           This variable conditionally defines the "HAS_ENDPWENT_R" symbol,
1121           which indicates to the C program that the endpwent_r() routine is
1122           available.
1123
1124       "d_endsent"
1125           From d_endsent.U:
1126
1127           This variable conditionally defines "HAS_ENDSERVENT" if
1128           endservent() is available to close whatever was being used for
1129           service queries.
1130
1131       "d_endservent_r"
1132           From d_endservent_r.U:
1133
1134           This variable conditionally defines the "HAS_ENDSERVENT_R" symbol,
1135           which indicates to the C program that the endservent_r() routine is
1136           available.
1137
1138       "d_eofnblk"
1139           From nblock_io.U:
1140
1141           This variable conditionally defines "EOF_NONBLOCK" if "EOF" can be
1142           seen when reading from a non-blocking I/O source.
1143
1144       "d_eunice"
1145           From Guess.U:
1146
1147           This variable conditionally defines the symbols "EUNICE" and "VAX",
1148           which alerts the C program that it must deal with ideosyncracies of
1149           "VMS".
1150
1151       "d_faststdio"
1152           From d_faststdio.U:
1153
1154           This variable conditionally defines the "HAS_FAST_STDIO" symbol,
1155           which indicates to the C program that the "fast stdio" is available
1156           to manipulate the stdio buffers directly.
1157
1158       "d_fchdir"
1159           From d_fchdir.U:
1160
1161           This variable conditionally defines the "HAS_FCHDIR" symbol, which
1162           indicates to the C program that the fchdir() routine is available.
1163
1164       "d_fchmod"
1165           From d_fchmod.U:
1166
1167           This variable conditionally defines the "HAS_FCHMOD" symbol, which
1168           indicates to the C program that the fchmod() routine is available
1169           to change mode of opened files.
1170
1171       "d_fchown"
1172           From d_fchown.U:
1173
1174           This variable conditionally defines the "HAS_FCHOWN" symbol, which
1175           indicates to the C program that the fchown() routine is available
1176           to change ownership of opened files.
1177
1178       "d_fcntl"
1179           From d_fcntl.U:
1180
1181           This variable conditionally defines the "HAS_FCNTL" symbol, and
1182           indicates whether the fcntl() function exists
1183
1184       "d_fcntl_can_lock"
1185           From d_fcntl_can_lock.U:
1186
1187           This variable conditionally defines the "FCNTL_CAN_LOCK" symbol and
1188           indicates whether file locking with fcntl() works.
1189
1190       "d_fd_macros"
1191           From d_fd_set.U:
1192
1193           This variable contains the eventual value of the "HAS_FD_MACROS"
1194           symbol, which indicates if your C compiler knows about the macros
1195           which manipulate an fd_set.
1196
1197       "d_fd_set"
1198           From d_fd_set.U:
1199
1200           This variable contains the eventual value of the "HAS_FD_SET"
1201           symbol, which indicates if your C compiler knows about the fd_set
1202           typedef.
1203
1204       "d_fds_bits"
1205           From d_fd_set.U:
1206
1207           This variable contains the eventual value of the "HAS_FDS_BITS"
1208           symbol, which indicates if your fd_set typedef contains the
1209           fds_bits member.  If you have an fd_set typedef, but the dweebs who
1210           installed it did a half-fast job and neglected to provide the
1211           macros to manipulate an fd_set, "HAS_FDS_BITS" will let us know how
1212           to fix the gaffe.
1213
1214       "d_fgetpos"
1215           From d_fgetpos.U:
1216
1217           This variable conditionally defines "HAS_FGETPOS" if fgetpos() is
1218           available to get the file position indicator.
1219
1220       "d_finite"
1221           From d_finite.U:
1222
1223           This variable conditionally defines the "HAS_FINITE" symbol, which
1224           indicates to the C program that the finite() routine is available.
1225
1226       "d_finitel"
1227           From d_finitel.U:
1228
1229           This variable conditionally defines the "HAS_FINITEL" symbol, which
1230           indicates to the C program that the finitel() routine is available.
1231
1232       "d_flexfnam"
1233           From d_flexfnam.U:
1234
1235           This variable conditionally defines the "FLEXFILENAMES" symbol,
1236           which indicates that the system supports filenames longer than 14
1237           characters.
1238
1239       "d_flock"
1240           From d_flock.U:
1241
1242           This variable conditionally defines "HAS_FLOCK" if flock() is
1243           available to do file locking.
1244
1245       "d_flockproto"
1246           From d_flockproto.U:
1247
1248           This variable conditionally defines the "HAS_FLOCK_PROTO" symbol,
1249           which indicates to the C program that the system provides a
1250           prototype for the flock() function.  Otherwise, it is up to the
1251           program to supply one.
1252
1253       "d_fork"
1254           From d_fork.U:
1255
1256           This variable conditionally defines the "HAS_FORK" symbol, which
1257           indicates to the C program that the fork() routine is available.
1258
1259       "d_fp_class"
1260           From d_fp_class.U:
1261
1262           This variable conditionally defines the "HAS_FP_CLASS" symbol,
1263           which indicates to the C program that the fp_class() routine is
1264           available.
1265
1266       "d_fpathconf"
1267           From d_pathconf.U:
1268
1269           This variable conditionally defines the "HAS_FPATHCONF" symbol,
1270           which indicates to the C program that the pathconf() routine is
1271           available to determine file-system related limits and options
1272           associated with a given open file descriptor.
1273
1274       "d_fpclass"
1275           From d_fpclass.U:
1276
1277           This variable conditionally defines the "HAS_FPCLASS" symbol, which
1278           indicates to the C program that the fpclass() routine is available.
1279
1280       "d_fpclassify"
1281           From d_fpclassify.U:
1282
1283           This variable conditionally defines the "HAS_FPCLASSIFY" symbol,
1284           which indicates to the C program that the fpclassify() routine is
1285           available.
1286
1287       "d_fpclassl"
1288           From d_fpclassl.U:
1289
1290           This variable conditionally defines the "HAS_FPCLASSL" symbol,
1291           which indicates to the C program that the fpclassl() routine is
1292           available.
1293
1294       "d_fpos64_t"
1295           From d_fpos64_t.U:
1296
1297           This symbol will be defined if the C compiler supports fpos64_t.
1298
1299       "d_frexpl"
1300           From d_frexpl.U:
1301
1302           This variable conditionally defines the "HAS_FREXPL" symbol, which
1303           indicates to the C program that the frexpl() routine is available.
1304
1305       "d_fs_data_s"
1306           From d_fs_data_s.U:
1307
1308           This variable conditionally defines the "HAS_STRUCT_FS_DATA"
1309           symbol, which indicates that the struct fs_data is supported.
1310
1311       "d_fseeko"
1312           From d_fseeko.U:
1313
1314           This variable conditionally defines the "HAS_FSEEKO" symbol, which
1315           indicates to the C program that the fseeko() routine is available.
1316
1317       "d_fsetpos"
1318           From d_fsetpos.U:
1319
1320           This variable conditionally defines "HAS_FSETPOS" if fsetpos() is
1321           available to set the file position indicator.
1322
1323       "d_fstatfs"
1324           From d_fstatfs.U:
1325
1326           This variable conditionally defines the "HAS_FSTATFS" symbol, which
1327           indicates to the C program that the fstatfs() routine is available.
1328
1329       "d_fstatvfs"
1330           From d_statvfs.U:
1331
1332           This variable conditionally defines the "HAS_FSTATVFS" symbol,
1333           which indicates to the C program that the fstatvfs() routine is
1334           available.
1335
1336       "d_fsync"
1337           From d_fsync.U:
1338
1339           This variable conditionally defines the "HAS_FSYNC" symbol, which
1340           indicates to the C program that the fsync() routine is available.
1341
1342       "d_ftello"
1343           From d_ftello.U:
1344
1345           This variable conditionally defines the "HAS_FTELLO" symbol, which
1346           indicates to the C program that the ftello() routine is available.
1347
1348       "d_ftime"
1349           From d_ftime.U:
1350
1351           This variable conditionally defines the "HAS_FTIME" symbol, which
1352           indicates that the ftime() routine exists.  The ftime() routine is
1353           basically a sub-second accuracy clock.
1354
1355       "d_futimes"
1356           From d_futimes.U:
1357
1358           This variable conditionally defines the "HAS_FUTIMES" symbol, which
1359           indicates to the C program that the futimes() routine is available.
1360
1361       "d_Gconvert"
1362           From d_gconvert.U:
1363
1364           This variable holds what Gconvert is defined as to convert floating
1365           point numbers into strings.  By default, Configure sets "this"
1366           macro to use the first of gconvert, gcvt, or sprintf that pass
1367           sprintf-%g-like behaviour tests.  If perl is using long doubles,
1368           the macro uses the first of the following functions that pass
1369           Configure's tests: qgcvt, sprintf (if Configure knows how to make
1370           sprintf format long doubles--see sPRIgldbl), gconvert, gcvt, and
1371           sprintf (casting to double).  The gconvert_preference and
1372           gconvert_ld_preference variables can be used to alter Configure's
1373           preferences, for doubles and long doubles, respectively.  If
1374           present, they contain a space-separated list of one or more of the
1375           above function names in the order they should be tried.
1376
1377           d_Gconvert may be set to override Configure with a platform-
1378           specific function.  If this function expects a double, a different
1379           value may need to be set by the uselongdouble.cbu call-back unit so
1380           that long doubles can be formatted without loss of precision.
1381
1382       "d_gdbm_ndbm_h_uses_prototypes"
1383           From i_ndbm.U:
1384
1385           This variable conditionally defines the "NDBM_H_USES_PROTOTYPES"
1386           symbol, which indicates that the gdbm-ndbm.h include file uses real
1387           "ANSI" C prototypes instead of K&R style function declarations. K&R
1388           style declarations are unsupported in C++, so the include file
1389           requires special handling when using a C++ compiler and this
1390           variable is undefined. Consult the different
1391           d_*ndbm_h_uses_prototypes variables to get the same information for
1392           alternative ndbm.h include files.
1393
1394       "d_gdbmndbm_h_uses_prototypes"
1395           From i_ndbm.U:
1396
1397           This variable conditionally defines the "NDBM_H_USES_PROTOTYPES"
1398           symbol, which indicates that the gdbm/ndbm.h include file uses real
1399           "ANSI" C prototypes instead of K&R style function declarations. K&R
1400           style declarations are unsupported in C++, so the include file
1401           requires special handling when using a C++ compiler and this
1402           variable is undefined. Consult the different
1403           d_*ndbm_h_uses_prototypes variables to get the same information for
1404           alternative ndbm.h include files.
1405
1406       "d_getaddrinfo"
1407           From d_getaddrinfo.U:
1408
1409           This variable conditionally defines the "HAS_GETADDRINFO" symbol,
1410           which indicates to the C program that the getaddrinfo() function is
1411           available.
1412
1413       "d_getcwd"
1414           From d_getcwd.U:
1415
1416           This variable conditionally defines the "HAS_GETCWD" symbol, which
1417           indicates to the C program that the getcwd() routine is available
1418           to get the current working directory.
1419
1420       "d_getespwnam"
1421           From d_getespwnam.U:
1422
1423           This variable conditionally defines "HAS_GETESPWNAM" if
1424           getespwnam() is available to retrieve enchanced (shadow) password
1425           entries by name.
1426
1427       "d_getfsstat"
1428           From d_getfsstat.U:
1429
1430           This variable conditionally defines the "HAS_GETFSSTAT" symbol,
1431           which indicates to the C program that the getfsstat() routine is
1432           available.
1433
1434       "d_getgrent"
1435           From d_getgrent.U:
1436
1437           This variable conditionally defines the "HAS_GETGRENT" symbol,
1438           which indicates to the C program that the getgrent() routine is
1439           available for sequential access of the group database.
1440
1441       "d_getgrent_r"
1442           From d_getgrent_r.U:
1443
1444           This variable conditionally defines the "HAS_GETGRENT_R" symbol,
1445           which indicates to the C program that the getgrent_r() routine is
1446           available.
1447
1448       "d_getgrgid_r"
1449           From d_getgrgid_r.U:
1450
1451           This variable conditionally defines the "HAS_GETGRGID_R" symbol,
1452           which indicates to the C program that the getgrgid_r() routine is
1453           available.
1454
1455       "d_getgrnam_r"
1456           From d_getgrnam_r.U:
1457
1458           This variable conditionally defines the "HAS_GETGRNAM_R" symbol,
1459           which indicates to the C program that the getgrnam_r() routine is
1460           available.
1461
1462       "d_getgrps"
1463           From d_getgrps.U:
1464
1465           This variable conditionally defines the "HAS_GETGROUPS" symbol,
1466           which indicates to the C program that the getgroups() routine is
1467           available to get the list of process groups.
1468
1469       "d_gethbyaddr"
1470           From d_gethbyad.U:
1471
1472           This variable conditionally defines the "HAS_GETHOSTBYADDR" symbol,
1473           which indicates to the C program that the gethostbyaddr() routine
1474           is available to look up hosts by their "IP" addresses.
1475
1476       "d_gethbyname"
1477           From d_gethbynm.U:
1478
1479           This variable conditionally defines the "HAS_GETHOSTBYNAME" symbol,
1480           which indicates to the C program that the gethostbyname() routine
1481           is available to look up host names in some data base or other.
1482
1483       "d_gethent"
1484           From d_gethent.U:
1485
1486           This variable conditionally defines "HAS_GETHOSTENT" if
1487           gethostent() is available to look up host names in some data base
1488           or another.
1489
1490       "d_gethname"
1491           From d_gethname.U:
1492
1493           This variable conditionally defines the "HAS_GETHOSTNAME" symbol,
1494           which indicates to the C program that the gethostname() routine may
1495           be used to derive the host name.
1496
1497       "d_gethostbyaddr_r"
1498           From d_gethostbyaddr_r.U:
1499
1500           This variable conditionally defines the "HAS_GETHOSTBYADDR_R"
1501           symbol, which indicates to the C program that the gethostbyaddr_r()
1502           routine is available.
1503
1504       "d_gethostbyname_r"
1505           From d_gethostbyname_r.U:
1506
1507           This variable conditionally defines the "HAS_GETHOSTBYNAME_R"
1508           symbol, which indicates to the C program that the gethostbyname_r()
1509           routine is available.
1510
1511       "d_gethostent_r"
1512           From d_gethostent_r.U:
1513
1514           This variable conditionally defines the "HAS_GETHOSTENT_R" symbol,
1515           which indicates to the C program that the gethostent_r() routine is
1516           available.
1517
1518       "d_gethostprotos"
1519           From d_gethostprotos.U:
1520
1521           This variable conditionally defines the "HAS_GETHOST_PROTOS"
1522           symbol, which indicates to the C program that <netdb.h> supplies
1523           prototypes for the various gethost*() functions.  See also
1524           netdbtype.U for probing for various netdb types.
1525
1526       "d_getitimer"
1527           From d_getitimer.U:
1528
1529           This variable conditionally defines the "HAS_GETITIMER" symbol,
1530           which indicates to the C program that the getitimer() routine is
1531           available.
1532
1533       "d_getlogin"
1534           From d_getlogin.U:
1535
1536           This variable conditionally defines the "HAS_GETLOGIN" symbol,
1537           which indicates to the C program that the getlogin() routine is
1538           available to get the login name.
1539
1540       "d_getlogin_r"
1541           From d_getlogin_r.U:
1542
1543           This variable conditionally defines the "HAS_GETLOGIN_R" symbol,
1544           which indicates to the C program that the getlogin_r() routine is
1545           available.
1546
1547       "d_getmnt"
1548           From d_getmnt.U:
1549
1550           This variable conditionally defines the "HAS_GETMNT" symbol, which
1551           indicates to the C program that the getmnt() routine is available
1552           to retrieve one or more mount info blocks by filename.
1553
1554       "d_getmntent"
1555           From d_getmntent.U:
1556
1557           This variable conditionally defines the "HAS_GETMNTENT" symbol,
1558           which indicates to the C program that the getmntent() routine is
1559           available to iterate through mounted files to get their mount info.
1560
1561       "d_getnameinfo"
1562           From d_getnameinfo.U:
1563
1564           This variable conditionally defines the "HAS_GETNAMEINFO" symbol,
1565           which indicates to the C program that the getnameinfo() function is
1566           available.
1567
1568       "d_getnbyaddr"
1569           From d_getnbyad.U:
1570
1571           This variable conditionally defines the "HAS_GETNETBYADDR" symbol,
1572           which indicates to the C program that the getnetbyaddr() routine is
1573           available to look up networks by their "IP" addresses.
1574
1575       "d_getnbyname"
1576           From d_getnbynm.U:
1577
1578           This variable conditionally defines the "HAS_GETNETBYNAME" symbol,
1579           which indicates to the C program that the getnetbyname() routine is
1580           available to look up networks by their names.
1581
1582       "d_getnent"
1583           From d_getnent.U:
1584
1585           This variable conditionally defines "HAS_GETNETENT" if getnetent()
1586           is available to look up network names in some data base or another.
1587
1588       "d_getnetbyaddr_r"
1589           From d_getnetbyaddr_r.U:
1590
1591           This variable conditionally defines the "HAS_GETNETBYADDR_R"
1592           symbol, which indicates to the C program that the getnetbyaddr_r()
1593           routine is available.
1594
1595       "d_getnetbyname_r"
1596           From d_getnetbyname_r.U:
1597
1598           This variable conditionally defines the "HAS_GETNETBYNAME_R"
1599           symbol, which indicates to the C program that the getnetbyname_r()
1600           routine is available.
1601
1602       "d_getnetent_r"
1603           From d_getnetent_r.U:
1604
1605           This variable conditionally defines the "HAS_GETNETENT_R" symbol,
1606           which indicates to the C program that the getnetent_r() routine is
1607           available.
1608
1609       "d_getnetprotos"
1610           From d_getnetprotos.U:
1611
1612           This variable conditionally defines the "HAS_GETNET_PROTOS" symbol,
1613           which indicates to the C program that <netdb.h> supplies prototypes
1614           for the various getnet*() functions.  See also netdbtype.U for
1615           probing for various netdb types.
1616
1617       "d_getpagsz"
1618           From d_getpagsz.U:
1619
1620           This variable conditionally defines "HAS_GETPAGESIZE" if
1621           getpagesize() is available to get the system page size.
1622
1623       "d_getpbyname"
1624           From d_getprotby.U:
1625
1626           This variable conditionally defines the "HAS_GETPROTOBYNAME"
1627           symbol, which indicates to the C program that the getprotobyname()
1628           routine is available to look up protocols by their name.
1629
1630       "d_getpbynumber"
1631           From d_getprotby.U:
1632
1633           This variable conditionally defines the "HAS_GETPROTOBYNUMBER"
1634           symbol, which indicates to the C program that the
1635           getprotobynumber() routine is available to look up protocols by
1636           their number.
1637
1638       "d_getpent"
1639           From d_getpent.U:
1640
1641           This variable conditionally defines "HAS_GETPROTOENT" if
1642           getprotoent() is available to look up protocols in some data base
1643           or another.
1644
1645       "d_getpgid"
1646           From d_getpgid.U:
1647
1648           This variable conditionally defines the "HAS_GETPGID" symbol, which
1649           indicates to the C program that the getpgid(pid) function is
1650           available to get the process group id.
1651
1652       "d_getpgrp"
1653           From d_getpgrp.U:
1654
1655           This variable conditionally defines "HAS_GETPGRP" if getpgrp() is
1656           available to get the current process group.
1657
1658       "d_getpgrp2"
1659           From d_getpgrp2.U:
1660
1661           This variable conditionally defines the HAS_GETPGRP2 symbol, which
1662           indicates to the C program that the getpgrp2() (as in DG/"UX")
1663           routine is available to get the current process group.
1664
1665       "d_getppid"
1666           From d_getppid.U:
1667
1668           This variable conditionally defines the "HAS_GETPPID" symbol, which
1669           indicates to the C program that the getppid() routine is available
1670           to get the parent process "ID".
1671
1672       "d_getprior"
1673           From d_getprior.U:
1674
1675           This variable conditionally defines "HAS_GETPRIORITY" if
1676           getpriority() is available to get a process's priority.
1677
1678       "d_getprotobyname_r"
1679           From d_getprotobyname_r.U:
1680
1681           This variable conditionally defines the "HAS_GETPROTOBYNAME_R"
1682           symbol, which indicates to the C program that the
1683           getprotobyname_r() routine is available.
1684
1685       "d_getprotobynumber_r"
1686           From d_getprotobynumber_r.U:
1687
1688           This variable conditionally defines the "HAS_GETPROTOBYNUMBER_R"
1689           symbol, which indicates to the C program that the
1690           getprotobynumber_r() routine is available.
1691
1692       "d_getprotoent_r"
1693           From d_getprotoent_r.U:
1694
1695           This variable conditionally defines the "HAS_GETPROTOENT_R" symbol,
1696           which indicates to the C program that the getprotoent_r() routine
1697           is available.
1698
1699       "d_getprotoprotos"
1700           From d_getprotoprotos.U:
1701
1702           This variable conditionally defines the "HAS_GETPROTO_PROTOS"
1703           symbol, which indicates to the C program that <netdb.h> supplies
1704           prototypes for the various getproto*() functions.  See also
1705           netdbtype.U for probing for various netdb types.
1706
1707       "d_getprpwnam"
1708           From d_getprpwnam.U:
1709
1710           This variable conditionally defines "HAS_GETPRPWNAM" if
1711           getprpwnam() is available to retrieve protected (shadow) password
1712           entries by name.
1713
1714       "d_getpwent"
1715           From d_getpwent.U:
1716
1717           This variable conditionally defines the "HAS_GETPWENT" symbol,
1718           which indicates to the C program that the getpwent() routine is
1719           available for sequential access of the passwd database.
1720
1721       "d_getpwent_r"
1722           From d_getpwent_r.U:
1723
1724           This variable conditionally defines the "HAS_GETPWENT_R" symbol,
1725           which indicates to the C program that the getpwent_r() routine is
1726           available.
1727
1728       "d_getpwnam_r"
1729           From d_getpwnam_r.U:
1730
1731           This variable conditionally defines the "HAS_GETPWNAM_R" symbol,
1732           which indicates to the C program that the getpwnam_r() routine is
1733           available.
1734
1735       "d_getpwuid_r"
1736           From d_getpwuid_r.U:
1737
1738           This variable conditionally defines the "HAS_GETPWUID_R" symbol,
1739           which indicates to the C program that the getpwuid_r() routine is
1740           available.
1741
1742       "d_getsbyname"
1743           From d_getsrvby.U:
1744
1745           This variable conditionally defines the "HAS_GETSERVBYNAME" symbol,
1746           which indicates to the C program that the getservbyname() routine
1747           is available to look up services by their name.
1748
1749       "d_getsbyport"
1750           From d_getsrvby.U:
1751
1752           This variable conditionally defines the "HAS_GETSERVBYPORT" symbol,
1753           which indicates to the C program that the getservbyport() routine
1754           is available to look up services by their port.
1755
1756       "d_getsent"
1757           From d_getsent.U:
1758
1759           This variable conditionally defines "HAS_GETSERVENT" if
1760           getservent() is available to look up network services in some data
1761           base or another.
1762
1763       "d_getservbyname_r"
1764           From d_getservbyname_r.U:
1765
1766           This variable conditionally defines the "HAS_GETSERVBYNAME_R"
1767           symbol, which indicates to the C program that the getservbyname_r()
1768           routine is available.
1769
1770       "d_getservbyport_r"
1771           From d_getservbyport_r.U:
1772
1773           This variable conditionally defines the "HAS_GETSERVBYPORT_R"
1774           symbol, which indicates to the C program that the getservbyport_r()
1775           routine is available.
1776
1777       "d_getservent_r"
1778           From d_getservent_r.U:
1779
1780           This variable conditionally defines the "HAS_GETSERVENT_R" symbol,
1781           which indicates to the C program that the getservent_r() routine is
1782           available.
1783
1784       "d_getservprotos"
1785           From d_getservprotos.U:
1786
1787           This variable conditionally defines the "HAS_GETSERV_PROTOS"
1788           symbol, which indicates to the C program that <netdb.h> supplies
1789           prototypes for the various getserv*() functions.  See also
1790           netdbtype.U for probing for various netdb types.
1791
1792       "d_getspnam"
1793           From d_getspnam.U:
1794
1795           This variable conditionally defines "HAS_GETSPNAM" if getspnam() is
1796           available to retrieve SysV shadow password entries by name.
1797
1798       "d_getspnam_r"
1799           From d_getspnam_r.U:
1800
1801           This variable conditionally defines the "HAS_GETSPNAM_R" symbol,
1802           which indicates to the C program that the getspnam_r() routine is
1803           available.
1804
1805       "d_gettimeod"
1806           From d_ftime.U:
1807
1808           This variable conditionally defines the "HAS_GETTIMEOFDAY" symbol,
1809           which indicates that the gettimeofday() system call exists (to
1810           obtain a sub-second accuracy clock). You should probably include
1811           <sys/resource.h>.
1812
1813       "d_gmtime64"
1814           From d_timefuncs64.U:
1815
1816           This variable conditionally defines the HAS_GMTIME64 symbol, which
1817           indicates to the C program that the gmtime64 () routine is
1818           available.
1819
1820       "d_gmtime_r"
1821           From d_gmtime_r.U:
1822
1823           This variable conditionally defines the "HAS_GMTIME_R" symbol,
1824           which indicates to the C program that the gmtime_r() routine is
1825           available.
1826
1827       "d_gnulibc"
1828           From d_gnulibc.U:
1829
1830           Defined if we're dealing with the "GNU" C Library.
1831
1832       "d_grpasswd"
1833           From i_grp.U:
1834
1835           This variable conditionally defines "GRPASSWD", which indicates
1836           that struct group in <grp.h> contains gr_passwd.
1837
1838       "d_hasmntopt"
1839           From d_hasmntopt.U:
1840
1841           This variable conditionally defines the "HAS_HASMNTOPT" symbol,
1842           which indicates to the C program that the hasmntopt() routine is
1843           available to query the mount options of file systems.
1844
1845       "d_htonl"
1846           From d_htonl.U:
1847
1848           This variable conditionally defines "HAS_HTONL" if htonl() and its
1849           friends are available to do network order byte swapping.
1850
1851       "d_ilogbl"
1852           From d_ilogbl.U:
1853
1854           This variable conditionally defines the "HAS_ILOGBL" symbol, which
1855           indicates to the C program that the ilogbl() routine is available.
1856           If scalbnl is also present we can emulate frexpl.
1857
1858       "d_inc_version_list"
1859           From inc_version_list.U:
1860
1861           This variable conditionally defines "PERL_INC_VERSION_LIST".  It is
1862           set to undef when "PERL_INC_VERSION_LIST" is empty.
1863
1864       "d_index"
1865           From d_strchr.U:
1866
1867           This variable conditionally defines "HAS_INDEX" if index() and
1868           rindex() are available for string searching.
1869
1870       "d_inetaton"
1871           From d_inetaton.U:
1872
1873           This variable conditionally defines the "HAS_INET_ATON" symbol,
1874           which indicates to the C program that the inet_aton() function is
1875           available to parse "IP" address "dotted-quad" strings.
1876
1877       "d_inetntop"
1878           From d_inetntop.U:
1879
1880           This variable conditionally defines the "HAS_INETNTOP" symbol,
1881           which indicates to the C program that the inet_ntop() function is
1882           available.
1883
1884       "d_inetpton"
1885           From d_inetpton.U:
1886
1887           This variable conditionally defines the "HAS_INETPTON" symbol,
1888           which indicates to the C program that the inet_pton() function is
1889           available.
1890
1891       "d_int64_t"
1892           From d_int64_t.U:
1893
1894           This symbol will be defined if the C compiler supports int64_t.
1895
1896       "d_isascii"
1897           From d_isascii.U:
1898
1899           This variable conditionally defines the "HAS_ISASCII" constant,
1900           which indicates to the C program that isascii() is available.
1901
1902       "d_isfinite"
1903           From d_isfinite.U:
1904
1905           This variable conditionally defines the "HAS_ISFINITE" symbol,
1906           which indicates to the C program that the isfinite() routine is
1907           available.
1908
1909       "d_isinf"
1910           From d_isinf.U:
1911
1912           This variable conditionally defines the "HAS_ISINF" symbol, which
1913           indicates to the C program that the isinf() routine is available.
1914
1915       "d_isnan"
1916           From d_isnan.U:
1917
1918           This variable conditionally defines the "HAS_ISNAN" symbol, which
1919           indicates to the C program that the isnan() routine is available.
1920
1921       "d_isnanl"
1922           From d_isnanl.U:
1923
1924           This variable conditionally defines the "HAS_ISNANL" symbol, which
1925           indicates to the C program that the isnanl() routine is available.
1926
1927       "d_killpg"
1928           From d_killpg.U:
1929
1930           This variable conditionally defines the "HAS_KILLPG" symbol, which
1931           indicates to the C program that the killpg() routine is available
1932           to kill process groups.
1933
1934       "d_lchown"
1935           From d_lchown.U:
1936
1937           This variable conditionally defines the "HAS_LCHOWN" symbol, which
1938           indicates to the C program that the lchown() routine is available
1939           to operate on a symbolic link (instead of following the link).
1940
1941       "d_ldbl_dig"
1942           From d_ldbl_dig.U:
1943
1944           This variable conditionally defines d_ldbl_dig if this system's
1945           header files provide "LDBL_DIG", which is the number of significant
1946           digits in a long double precision number.
1947
1948       "d_libm_lib_version"
1949           From d_libm_lib_version.U:
1950
1951           This variable conditionally defines the "LIBM_LIB_VERSION" symbol,
1952           which indicates to the C program that math.h defines "_LIB_VERSION"
1953           being available in libm
1954
1955       "d_link"
1956           From d_link.U:
1957
1958           This variable conditionally defines "HAS_LINK" if link() is
1959           available to create hard links.
1960
1961       "d_localtime64"
1962           From d_timefuncs64.U:
1963
1964           This variable conditionally defines the HAS_LOCALTIME64 symbol,
1965           which indicates to the C program that the localtime64 () routine is
1966           available.
1967
1968       "d_localtime_r"
1969           From d_localtime_r.U:
1970
1971           This variable conditionally defines the "HAS_LOCALTIME_R" symbol,
1972           which indicates to the C program that the localtime_r() routine is
1973           available.
1974
1975       "d_localtime_r_needs_tzset"
1976           From d_localtime_r.U:
1977
1978           This variable conditionally defines the "LOCALTIME_R_NEEDS_TZSET"
1979           symbol, which makes us call tzset before localtime_r()
1980
1981       "d_locconv"
1982           From d_locconv.U:
1983
1984           This variable conditionally defines "HAS_LOCALECONV" if
1985           localeconv() is available for numeric and monetary formatting
1986           conventions.
1987
1988       "d_lockf"
1989           From d_lockf.U:
1990
1991           This variable conditionally defines "HAS_LOCKF" if lockf() is
1992           available to do file locking.
1993
1994       "d_longdbl"
1995           From d_longdbl.U:
1996
1997           This variable conditionally defines "HAS_LONG_DOUBLE" if the long
1998           double type is supported.
1999
2000       "d_longlong"
2001           From d_longlong.U:
2002
2003           This variable conditionally defines "HAS_LONG_LONG" if the long
2004           long type is supported.
2005
2006       "d_lseekproto"
2007           From d_lseekproto.U:
2008
2009           This variable conditionally defines the "HAS_LSEEK_PROTO" symbol,
2010           which indicates to the C program that the system provides a
2011           prototype for the lseek() function.  Otherwise, it is up to the
2012           program to supply one.
2013
2014       "d_lstat"
2015           From d_lstat.U:
2016
2017           This variable conditionally defines "HAS_LSTAT" if lstat() is
2018           available to do file stats on symbolic links.
2019
2020       "d_madvise"
2021           From d_madvise.U:
2022
2023           This variable conditionally defines "HAS_MADVISE" if madvise() is
2024           available to map a file into memory.
2025
2026       "d_malloc_good_size"
2027           From d_malloc_size.U:
2028
2029           This symbol, if defined, indicates that the malloc_good_size
2030           routine is available for use.
2031
2032       "d_malloc_size"
2033           From d_malloc_size.U:
2034
2035           This symbol, if defined, indicates that the malloc_size routine is
2036           available for use.
2037
2038       "d_mblen"
2039           From d_mblen.U:
2040
2041           This variable conditionally defines the "HAS_MBLEN" symbol, which
2042           indicates to the C program that the mblen() routine is available to
2043           find the number of bytes in a multibye character.
2044
2045       "d_mbstowcs"
2046           From d_mbstowcs.U:
2047
2048           This variable conditionally defines the "HAS_MBSTOWCS" symbol,
2049           which indicates to the C program that the mbstowcs() routine is
2050           available to convert a multibyte string into a wide character
2051           string.
2052
2053       "d_mbtowc"
2054           From d_mbtowc.U:
2055
2056           This variable conditionally defines the "HAS_MBTOWC" symbol, which
2057           indicates to the C program that the mbtowc() routine is available
2058           to convert multibyte to a wide character.
2059
2060       "d_memchr"
2061           From d_memchr.U:
2062
2063           This variable conditionally defines the "HAS_MEMCHR" symbol, which
2064           indicates to the C program that the memchr() routine is available
2065           to locate characters within a C string.
2066
2067       "d_memcmp"
2068           From d_memcmp.U:
2069
2070           This variable conditionally defines the "HAS_MEMCMP" symbol, which
2071           indicates to the C program that the memcmp() routine is available
2072           to compare blocks of memory.
2073
2074       "d_memcpy"
2075           From d_memcpy.U:
2076
2077           This variable conditionally defines the "HAS_MEMCPY" symbol, which
2078           indicates to the C program that the memcpy() routine is available
2079           to copy blocks of memory.
2080
2081       "d_memmove"
2082           From d_memmove.U:
2083
2084           This variable conditionally defines the "HAS_MEMMOVE" symbol, which
2085           indicates to the C program that the memmove() routine is available
2086           to copy potentatially overlapping blocks of memory.
2087
2088       "d_memset"
2089           From d_memset.U:
2090
2091           This variable conditionally defines the "HAS_MEMSET" symbol, which
2092           indicates to the C program that the memset() routine is available
2093           to set blocks of memory.
2094
2095       "d_mkdir"
2096           From d_mkdir.U:
2097
2098           This variable conditionally defines the "HAS_MKDIR" symbol, which
2099           indicates to the C program that the mkdir() routine is available to
2100           create directories..
2101
2102       "d_mkdtemp"
2103           From d_mkdtemp.U:
2104
2105           This variable conditionally defines the "HAS_MKDTEMP" symbol, which
2106           indicates to the C program that the mkdtemp() routine is available
2107           to exclusively create a uniquely named temporary directory.
2108
2109       "d_mkfifo"
2110           From d_mkfifo.U:
2111
2112           This variable conditionally defines the "HAS_MKFIFO" symbol, which
2113           indicates to the C program that the mkfifo() routine is available.
2114
2115       "d_mkstemp"
2116           From d_mkstemp.U:
2117
2118           This variable conditionally defines the "HAS_MKSTEMP" symbol, which
2119           indicates to the C program that the mkstemp() routine is available
2120           to exclusively create and open a uniquely named temporary file.
2121
2122       "d_mkstemps"
2123           From d_mkstemps.U:
2124
2125           This variable conditionally defines the "HAS_MKSTEMPS" symbol,
2126           which indicates to the C program that the mkstemps() routine is
2127           available to exclusively create and open a uniquely named (with a
2128           suffix) temporary file.
2129
2130       "d_mktime"
2131           From d_mktime.U:
2132
2133           This variable conditionally defines the "HAS_MKTIME" symbol, which
2134           indicates to the C program that the mktime() routine is available.
2135
2136       "d_mktime64"
2137           From d_timefuncs64.U:
2138
2139           This variable conditionally defines the HAS_MKTIME64 symbol, which
2140           indicates to the C program that the mktime64 () routine is
2141           available.
2142
2143       "d_mmap"
2144           From d_mmap.U:
2145
2146           This variable conditionally defines "HAS_MMAP" if mmap() is
2147           available to map a file into memory.
2148
2149       "d_modfl"
2150           From d_modfl.U:
2151
2152           This variable conditionally defines the "HAS_MODFL" symbol, which
2153           indicates to the C program that the modfl() routine is available.
2154
2155       "d_modfl_pow32_bug"
2156           From d_modfl.U:
2157
2158           This variable conditionally defines the HAS_MODFL_POW32_BUG symbol,
2159           which indicates that modfl() is broken for long doubles >= pow(2,
2160           32).  For example from 4294967303.150000 one would get
2161           4294967302.000000 and 1.150000.  The bug has been seen in certain
2162           versions of glibc, release 2.2.2 is known to be okay.
2163
2164       "d_modflproto"
2165           From d_modfl.U:
2166
2167           This symbol, if defined, indicates that the system provides a
2168           prototype for the modfl() function.  Otherwise, it is up to the
2169           program to supply one.  C99 says it should be long double
2170           modfl(long double, long double *);
2171
2172       "d_mprotect"
2173           From d_mprotect.U:
2174
2175           This variable conditionally defines "HAS_MPROTECT" if mprotect() is
2176           available to modify the access protection of a memory mapped file.
2177
2178       "d_msg"
2179           From d_msg.U:
2180
2181           This variable conditionally defines the "HAS_MSG" symbol, which
2182           indicates that the entire msg*(2) library is present.
2183
2184       "d_msg_ctrunc"
2185           From d_socket.U:
2186
2187           This variable conditionally defines the "HAS_MSG_CTRUNC" symbol,
2188           which indicates that the "MSG_CTRUNC" is available.  #ifdef is not
2189           enough because it may be an enum, glibc has been known to do this.
2190
2191       "d_msg_dontroute"
2192           From d_socket.U:
2193
2194           This variable conditionally defines the "HAS_MSG_DONTROUTE" symbol,
2195           which indicates that the "MSG_DONTROUTE" is available.  #ifdef is
2196           not enough because it may be an enum, glibc has been known to do
2197           this.
2198
2199       "d_msg_oob"
2200           From d_socket.U:
2201
2202           This variable conditionally defines the "HAS_MSG_OOB" symbol, which
2203           indicates that the "MSG_OOB" is available.  #ifdef is not enough
2204           because it may be an enum, glibc has been known to do this.
2205
2206       "d_msg_peek"
2207           From d_socket.U:
2208
2209           This variable conditionally defines the "HAS_MSG_PEEK" symbol,
2210           which indicates that the "MSG_PEEK" is available.  #ifdef is not
2211           enough because it may be an enum, glibc has been known to do this.
2212
2213       "d_msg_proxy"
2214           From d_socket.U:
2215
2216           This variable conditionally defines the "HAS_MSG_PROXY" symbol,
2217           which indicates that the "MSG_PROXY" is available.  #ifdef is not
2218           enough because it may be an enum, glibc has been known to do this.
2219
2220       "d_msgctl"
2221           From d_msgctl.U:
2222
2223           This variable conditionally defines the "HAS_MSGCTL" symbol, which
2224           indicates to the C program that the msgctl() routine is available.
2225
2226       "d_msgget"
2227           From d_msgget.U:
2228
2229           This variable conditionally defines the "HAS_MSGGET" symbol, which
2230           indicates to the C program that the msgget() routine is available.
2231
2232       "d_msghdr_s"
2233           From d_msghdr_s.U:
2234
2235           This variable conditionally defines the "HAS_STRUCT_MSGHDR" symbol,
2236           which indicates that the struct msghdr is supported.
2237
2238       "d_msgrcv"
2239           From d_msgrcv.U:
2240
2241           This variable conditionally defines the "HAS_MSGRCV" symbol, which
2242           indicates to the C program that the msgrcv() routine is available.
2243
2244       "d_msgsnd"
2245           From d_msgsnd.U:
2246
2247           This variable conditionally defines the "HAS_MSGSND" symbol, which
2248           indicates to the C program that the msgsnd() routine is available.
2249
2250       "d_msync"
2251           From d_msync.U:
2252
2253           This variable conditionally defines "HAS_MSYNC" if msync() is
2254           available to synchronize a mapped file.
2255
2256       "d_munmap"
2257           From d_munmap.U:
2258
2259           This variable conditionally defines "HAS_MUNMAP" if munmap() is
2260           available to unmap a region mapped by mmap().
2261
2262       "d_mymalloc"
2263           From mallocsrc.U:
2264
2265           This variable conditionally defines "MYMALLOC" in case other parts
2266           of the source want to take special action if "MYMALLOC" is used.
2267           This may include different sorts of profiling or error detection.
2268
2269       "d_ndbm"
2270           From i_ndbm.U:
2271
2272           This variable conditionally defines the "HAS_NDBM" symbol, which
2273           indicates that both the ndbm.h include file and an appropriate ndbm
2274           library exist.  Consult the different i_*ndbm variables to find out
2275           the actual include location.  Sometimes, a system has the header
2276           file but not the library.  This variable will only be set if the
2277           system has both.
2278
2279       "d_ndbm_h_uses_prototypes"
2280           From i_ndbm.U:
2281
2282           This variable conditionally defines the "NDBM_H_USES_PROTOTYPES"
2283           symbol, which indicates that the ndbm.h include file uses real
2284           "ANSI" C prototypes instead of K&R style function declarations. K&R
2285           style declarations are unsupported in C++, so the include file
2286           requires special handling when using a C++ compiler and this
2287           variable is undefined. Consult the different
2288           d_*ndbm_h_uses_prototypes variables to get the same information for
2289           alternative ndbm.h include files.
2290
2291       "d_nice"
2292           From d_nice.U:
2293
2294           This variable conditionally defines the "HAS_NICE" symbol, which
2295           indicates to the C program that the nice() routine is available.
2296
2297       "d_nl_langinfo"
2298           From d_nl_langinfo.U:
2299
2300           This variable conditionally defines the "HAS_NL_LANGINFO" symbol,
2301           which indicates to the C program that the nl_langinfo() routine is
2302           available.
2303
2304       "d_nv_preserves_uv"
2305           From perlxv.U:
2306
2307           This variable indicates whether a variable of type nvtype can
2308           preserve all the bits a variable of type uvtype.
2309
2310       "d_nv_zero_is_allbits_zero"
2311           From perlxv.U:
2312
2313           This variable indicates whether a variable of type nvtype stores
2314           0.0 in memory as all bits zero.
2315
2316       "d_off64_t"
2317           From d_off64_t.U:
2318
2319           This symbol will be defined if the C compiler supports off64_t.
2320
2321       "d_old_pthread_create_joinable"
2322           From d_pthrattrj.U:
2323
2324           This variable conditionally defines pthread_create_joinable.  undef
2325           if pthread.h defines "PTHREAD_CREATE_JOINABLE".
2326
2327       "d_oldpthreads"
2328           From usethreads.U:
2329
2330           This variable conditionally defines the "OLD_PTHREADS_API" symbol,
2331           and indicates that Perl should be built to use the old draft
2332           "POSIX" threads "API".  This is only potentially meaningful if
2333           usethreads is set.
2334
2335       "d_oldsock"
2336           From d_socket.U:
2337
2338           This variable conditionally defines the "OLDSOCKET" symbol, which
2339           indicates that the "BSD" socket interface is based on 4.1c and not
2340           4.2.
2341
2342       "d_open3"
2343           From d_open3.U:
2344
2345           This variable conditionally defines the HAS_OPEN3 manifest
2346           constant, which indicates to the C program that the 3 argument
2347           version of the open(2) function is available.
2348
2349       "d_pathconf"
2350           From d_pathconf.U:
2351
2352           This variable conditionally defines the "HAS_PATHCONF" symbol,
2353           which indicates to the C program that the pathconf() routine is
2354           available to determine file-system related limits and options
2355           associated with a given filename.
2356
2357       "d_pause"
2358           From d_pause.U:
2359
2360           This variable conditionally defines the "HAS_PAUSE" symbol, which
2361           indicates to the C program that the pause() routine is available to
2362           suspend a process until a signal is received.
2363
2364       "d_perl_otherlibdirs"
2365           From otherlibdirs.U:
2366
2367           This variable conditionally defines "PERL_OTHERLIBDIRS", which
2368           contains a colon-separated set of paths for the perl binary to
2369           include in @"INC".  See also otherlibdirs.
2370
2371       "d_phostname"
2372           From d_gethname.U:
2373
2374           This variable conditionally defines the "HAS_PHOSTNAME" symbol,
2375           which contains the shell command which, when fed to popen(), may be
2376           used to derive the host name.
2377
2378       "d_pipe"
2379           From d_pipe.U:
2380
2381           This variable conditionally defines the "HAS_PIPE" symbol, which
2382           indicates to the C program that the pipe() routine is available to
2383           create an inter-process channel.
2384
2385       "d_poll"
2386           From d_poll.U:
2387
2388           This variable conditionally defines the "HAS_POLL" symbol, which
2389           indicates to the C program that the poll() routine is available to
2390           poll active file descriptors.
2391
2392       "d_portable"
2393           From d_portable.U:
2394
2395           This variable conditionally defines the "PORTABLE" symbol, which
2396           indicates to the C program that it should not assume that it is
2397           running on the machine it was compiled on.
2398
2399       "d_PRId64"
2400           From quadfio.U:
2401
2402           This variable conditionally defines the PERL_PRId64 symbol, which
2403           indiciates that stdio has a symbol to print 64-bit decimal numbers.
2404
2405       "d_PRIeldbl"
2406           From longdblfio.U:
2407
2408           This variable conditionally defines the PERL_PRIfldbl symbol, which
2409           indiciates that stdio has a symbol to print long doubles.
2410
2411       "d_PRIEUldbl"
2412           From longdblfio.U:
2413
2414           This variable conditionally defines the PERL_PRIfldbl symbol, which
2415           indiciates that stdio has a symbol to print long doubles.  The "U"
2416           in the name is to separate this from d_PRIeldbl so that even case-
2417           blind systems can see the difference.
2418
2419       "d_PRIfldbl"
2420           From longdblfio.U:
2421
2422           This variable conditionally defines the PERL_PRIfldbl symbol, which
2423           indiciates that stdio has a symbol to print long doubles.
2424
2425       "d_PRIFUldbl"
2426           From longdblfio.U:
2427
2428           This variable conditionally defines the PERL_PRIfldbl symbol, which
2429           indiciates that stdio has a symbol to print long doubles.  The "U"
2430           in the name is to separate this from d_PRIfldbl so that even case-
2431           blind systems can see the difference.
2432
2433       "d_PRIgldbl"
2434           From longdblfio.U:
2435
2436           This variable conditionally defines the PERL_PRIfldbl symbol, which
2437           indiciates that stdio has a symbol to print long doubles.
2438
2439       "d_PRIGUldbl"
2440           From longdblfio.U:
2441
2442           This variable conditionally defines the PERL_PRIfldbl symbol, which
2443           indiciates that stdio has a symbol to print long doubles.  The "U"
2444           in the name is to separate this from d_PRIgldbl so that even case-
2445           blind systems can see the difference.
2446
2447       "d_PRIi64"
2448           From quadfio.U:
2449
2450           This variable conditionally defines the PERL_PRIi64 symbol, which
2451           indiciates that stdio has a symbol to print 64-bit decimal numbers.
2452
2453       "d_printf_format_null"
2454           From d_attribut.U:
2455
2456           This variable conditionally defines "PRINTF_FORMAT_NULL_OK", which
2457           indicates the C compiler allows printf-like formats to be null.
2458
2459       "d_PRIo64"
2460           From quadfio.U:
2461
2462           This variable conditionally defines the PERL_PRIo64 symbol, which
2463           indiciates that stdio has a symbol to print 64-bit octal numbers.
2464
2465       "d_PRIu64"
2466           From quadfio.U:
2467
2468           This variable conditionally defines the PERL_PRIu64 symbol, which
2469           indiciates that stdio has a symbol to print 64-bit unsigned decimal
2470           numbers.
2471
2472       "d_PRIx64"
2473           From quadfio.U:
2474
2475           This variable conditionally defines the PERL_PRIx64 symbol, which
2476           indiciates that stdio has a symbol to print 64-bit hexadecimal
2477           numbers.
2478
2479       "d_PRIXU64"
2480           From quadfio.U:
2481
2482           This variable conditionally defines the PERL_PRIXU64 symbol, which
2483           indiciates that stdio has a symbol to print 64-bit hExADECimAl
2484           numbers.  The "U" in the name is to separate this from d_PRIx64 so
2485           that even case-blind systems can see the difference.
2486
2487       "d_procselfexe"
2488           From d_procselfexe.U:
2489
2490           Defined if $procselfexe is symlink to the absolute pathname of the
2491           executing program.
2492
2493       "d_pseudofork"
2494           From d_vfork.U:
2495
2496           This variable conditionally defines the "HAS_PSEUDOFORK" symbol,
2497           which indicates that an emulation of the fork routine is available.
2498
2499       "d_pthread_atfork"
2500           From d_pthread_atfork.U:
2501
2502           This variable conditionally defines the "HAS_PTHREAD_ATFORK"
2503           symbol, which indicates to the C program that the pthread_atfork()
2504           routine is available.
2505
2506       "d_pthread_attr_setscope"
2507           From d_pthread_attr_ss.U:
2508
2509           This variable conditionally defines "HAS_PTHREAD_ATTR_SETSCOPE" if
2510           pthread_attr_setscope() is available to set the contention scope
2511           attribute of a thread attribute object.
2512
2513       "d_pthread_yield"
2514           From d_pthread_y.U:
2515
2516           This variable conditionally defines the "HAS_PTHREAD_YIELD" symbol
2517           if the pthread_yield routine is available to yield the execution of
2518           the current thread.
2519
2520       "d_pwage"
2521           From i_pwd.U:
2522
2523           This variable conditionally defines "PWAGE", which indicates that
2524           struct passwd contains pw_age.
2525
2526       "d_pwchange"
2527           From i_pwd.U:
2528
2529           This variable conditionally defines "PWCHANGE", which indicates
2530           that struct passwd contains pw_change.
2531
2532       "d_pwclass"
2533           From i_pwd.U:
2534
2535           This variable conditionally defines "PWCLASS", which indicates that
2536           struct passwd contains pw_class.
2537
2538       "d_pwcomment"
2539           From i_pwd.U:
2540
2541           This variable conditionally defines "PWCOMMENT", which indicates
2542           that struct passwd contains pw_comment.
2543
2544       "d_pwexpire"
2545           From i_pwd.U:
2546
2547           This variable conditionally defines "PWEXPIRE", which indicates
2548           that struct passwd contains pw_expire.
2549
2550       "d_pwgecos"
2551           From i_pwd.U:
2552
2553           This variable conditionally defines "PWGECOS", which indicates that
2554           struct passwd contains pw_gecos.
2555
2556       "d_pwpasswd"
2557           From i_pwd.U:
2558
2559           This variable conditionally defines "PWPASSWD", which indicates
2560           that struct passwd contains pw_passwd.
2561
2562       "d_pwquota"
2563           From i_pwd.U:
2564
2565           This variable conditionally defines "PWQUOTA", which indicates that
2566           struct passwd contains pw_quota.
2567
2568       "d_qgcvt"
2569           From d_qgcvt.U:
2570
2571           This variable conditionally defines the "HAS_QGCVT" symbol, which
2572           indicates to the C program that the qgcvt() routine is available.
2573
2574       "d_quad"
2575           From quadtype.U:
2576
2577           This variable, if defined, tells that there's a 64-bit integer
2578           type, quadtype.
2579
2580       "d_random_r"
2581           From d_random_r.U:
2582
2583           This variable conditionally defines the "HAS_RANDOM_R" symbol,
2584           which indicates to the C program that the random_r() routine is
2585           available.
2586
2587       "d_readdir"
2588           From d_readdir.U:
2589
2590           This variable conditionally defines "HAS_READDIR" if readdir() is
2591           available to read directory entries.
2592
2593       "d_readdir64_r"
2594           From d_readdir64_r.U:
2595
2596           This variable conditionally defines the HAS_READDIR64_R symbol,
2597           which indicates to the C program that the readdir64_r() routine is
2598           available.
2599
2600       "d_readdir_r"
2601           From d_readdir_r.U:
2602
2603           This variable conditionally defines the "HAS_READDIR_R" symbol,
2604           which indicates to the C program that the readdir_r() routine is
2605           available.
2606
2607       "d_readlink"
2608           From d_readlink.U:
2609
2610           This variable conditionally defines the "HAS_READLINK" symbol,
2611           which indicates to the C program that the readlink() routine is
2612           available to read the value of a symbolic link.
2613
2614       "d_readv"
2615           From d_readv.U:
2616
2617           This variable conditionally defines the "HAS_READV" symbol, which
2618           indicates to the C program that the readv() routine is available.
2619
2620       "d_recvmsg"
2621           From d_recvmsg.U:
2622
2623           This variable conditionally defines the "HAS_RECVMSG" symbol, which
2624           indicates to the C program that the recvmsg() routine is available.
2625
2626       "d_rename"
2627           From d_rename.U:
2628
2629           This variable conditionally defines the "HAS_RENAME" symbol, which
2630           indicates to the C program that the rename() routine is available
2631           to rename files.
2632
2633       "d_rewinddir"
2634           From d_readdir.U:
2635
2636           This variable conditionally defines "HAS_REWINDDIR" if rewinddir()
2637           is available.
2638
2639       "d_rmdir"
2640           From d_rmdir.U:
2641
2642           This variable conditionally defines "HAS_RMDIR" if rmdir() is
2643           available to remove directories.
2644
2645       "d_safebcpy"
2646           From d_safebcpy.U:
2647
2648           This variable conditionally defines the "HAS_SAFE_BCOPY" symbol if
2649           the bcopy() routine can do overlapping copies.  Normally, you
2650           should probably use memmove().
2651
2652       "d_safemcpy"
2653           From d_safemcpy.U:
2654
2655           This variable conditionally defines the "HAS_SAFE_MEMCPY" symbol if
2656           the memcpy() routine can do overlapping copies.  For overlapping
2657           copies, memmove() should be used, if available.
2658
2659       "d_sanemcmp"
2660           From d_sanemcmp.U:
2661
2662           This variable conditionally defines the "HAS_SANE_MEMCMP" symbol if
2663           the memcpy() routine is available and can be used to compare
2664           relative magnitudes of chars with their high bits set.
2665
2666       "d_sbrkproto"
2667           From d_sbrkproto.U:
2668
2669           This variable conditionally defines the "HAS_SBRK_PROTO" symbol,
2670           which indicates to the C program that the system provides a
2671           prototype for the sbrk() function.  Otherwise, it is up to the
2672           program to supply one.
2673
2674       "d_scalbnl"
2675           From d_scalbnl.U:
2676
2677           This variable conditionally defines the "HAS_SCALBNL" symbol, which
2678           indicates to the C program that the scalbnl() routine is available.
2679           If ilogbl is also present we can emulate frexpl.
2680
2681       "d_sched_yield"
2682           From d_pthread_y.U:
2683
2684           This variable conditionally defines the "HAS_SCHED_YIELD" symbol if
2685           the sched_yield routine is available to yield the execution of the
2686           current thread.
2687
2688       "d_scm_rights"
2689           From d_socket.U:
2690
2691           This variable conditionally defines the "HAS_SCM_RIGHTS" symbol,
2692           which indicates that the "SCM_RIGHTS" is available.  #ifdef is not
2693           enough because it may be an enum, glibc has been known to do this.
2694
2695       "d_SCNfldbl"
2696           From longdblfio.U:
2697
2698           This variable conditionally defines the PERL_PRIfldbl symbol, which
2699           indiciates that stdio has a symbol to scan long doubles.
2700
2701       "d_seekdir"
2702           From d_readdir.U:
2703
2704           This variable conditionally defines "HAS_SEEKDIR" if seekdir() is
2705           available.
2706
2707       "d_select"
2708           From d_select.U:
2709
2710           This variable conditionally defines "HAS_SELECT" if select() is
2711           available to select active file descriptors. A <sys/time.h>
2712           inclusion may be necessary for the timeout field.
2713
2714       "d_sem"
2715           From d_sem.U:
2716
2717           This variable conditionally defines the "HAS_SEM" symbol, which
2718           indicates that the entire sem*(2) library is present.
2719
2720       "d_semctl"
2721           From d_semctl.U:
2722
2723           This variable conditionally defines the "HAS_SEMCTL" symbol, which
2724           indicates to the C program that the semctl() routine is available.
2725
2726       "d_semctl_semid_ds"
2727           From d_union_semun.U:
2728
2729           This variable conditionally defines "USE_SEMCTL_SEMID_DS", which
2730           indicates that struct semid_ds * is to be used for semctl
2731           "IPC_STAT".
2732
2733       "d_semctl_semun"
2734           From d_union_semun.U:
2735
2736           This variable conditionally defines "USE_SEMCTL_SEMUN", which
2737           indicates that union semun is to be used for semctl "IPC_STAT".
2738
2739       "d_semget"
2740           From d_semget.U:
2741
2742           This variable conditionally defines the "HAS_SEMGET" symbol, which
2743           indicates to the C program that the semget() routine is available.
2744
2745       "d_semop"
2746           From d_semop.U:
2747
2748           This variable conditionally defines the "HAS_SEMOP" symbol, which
2749           indicates to the C program that the semop() routine is available.
2750
2751       "d_sendmsg"
2752           From d_sendmsg.U:
2753
2754           This variable conditionally defines the "HAS_SENDMSG" symbol, which
2755           indicates to the C program that the sendmsg() routine is available.
2756
2757       "d_setegid"
2758           From d_setegid.U:
2759
2760           This variable conditionally defines the "HAS_SETEGID" symbol, which
2761           indicates to the C program that the setegid() routine is available
2762           to change the effective gid of the current program.
2763
2764       "d_seteuid"
2765           From d_seteuid.U:
2766
2767           This variable conditionally defines the "HAS_SETEUID" symbol, which
2768           indicates to the C program that the seteuid() routine is available
2769           to change the effective uid of the current program.
2770
2771       "d_setgrent"
2772           From d_setgrent.U:
2773
2774           This variable conditionally defines the "HAS_SETGRENT" symbol,
2775           which indicates to the C program that the setgrent() routine is
2776           available for initializing sequential access to the group database.
2777
2778       "d_setgrent_r"
2779           From d_setgrent_r.U:
2780
2781           This variable conditionally defines the "HAS_SETGRENT_R" symbol,
2782           which indicates to the C program that the setgrent_r() routine is
2783           available.
2784
2785       "d_setgrps"
2786           From d_setgrps.U:
2787
2788           This variable conditionally defines the "HAS_SETGROUPS" symbol,
2789           which indicates to the C program that the setgroups() routine is
2790           available to set the list of process groups.
2791
2792       "d_sethent"
2793           From d_sethent.U:
2794
2795           This variable conditionally defines "HAS_SETHOSTENT" if
2796           sethostent() is available.
2797
2798       "d_sethostent_r"
2799           From d_sethostent_r.U:
2800
2801           This variable conditionally defines the "HAS_SETHOSTENT_R" symbol,
2802           which indicates to the C program that the sethostent_r() routine is
2803           available.
2804
2805       "d_setitimer"
2806           From d_setitimer.U:
2807
2808           This variable conditionally defines the "HAS_SETITIMER" symbol,
2809           which indicates to the C program that the setitimer() routine is
2810           available.
2811
2812       "d_setlinebuf"
2813           From d_setlnbuf.U:
2814
2815           This variable conditionally defines the "HAS_SETLINEBUF" symbol,
2816           which indicates to the C program that the setlinebuf() routine is
2817           available to change stderr or stdout from block-buffered or
2818           unbuffered to a line-buffered mode.
2819
2820       "d_setlocale"
2821           From d_setlocale.U:
2822
2823           This variable conditionally defines "HAS_SETLOCALE" if setlocale()
2824           is available to handle locale-specific ctype implementations.
2825
2826       "d_setlocale_r"
2827           From d_setlocale_r.U:
2828
2829           This variable conditionally defines the "HAS_SETLOCALE_R" symbol,
2830           which indicates to the C program that the setlocale_r() routine is
2831           available.
2832
2833       "d_setnent"
2834           From d_setnent.U:
2835
2836           This variable conditionally defines "HAS_SETNETENT" if setnetent()
2837           is available.
2838
2839       "d_setnetent_r"
2840           From d_setnetent_r.U:
2841
2842           This variable conditionally defines the "HAS_SETNETENT_R" symbol,
2843           which indicates to the C program that the setnetent_r() routine is
2844           available.
2845
2846       "d_setpent"
2847           From d_setpent.U:
2848
2849           This variable conditionally defines "HAS_SETPROTOENT" if
2850           setprotoent() is available.
2851
2852       "d_setpgid"
2853           From d_setpgid.U:
2854
2855           This variable conditionally defines the "HAS_SETPGID" symbol if the
2856           setpgid(pid, gpid) function is available to set process group "ID".
2857
2858       "d_setpgrp"
2859           From d_setpgrp.U:
2860
2861           This variable conditionally defines "HAS_SETPGRP" if setpgrp() is
2862           available to set the current process group.
2863
2864       "d_setpgrp2"
2865           From d_setpgrp2.U:
2866
2867           This variable conditionally defines the HAS_SETPGRP2 symbol, which
2868           indicates to the C program that the setpgrp2() (as in DG/"UX")
2869           routine is available to set the current process group.
2870
2871       "d_setprior"
2872           From d_setprior.U:
2873
2874           This variable conditionally defines "HAS_SETPRIORITY" if
2875           setpriority() is available to set a process's priority.
2876
2877       "d_setproctitle"
2878           From d_setproctitle.U:
2879
2880           This variable conditionally defines the "HAS_SETPROCTITLE" symbol,
2881           which indicates to the C program that the setproctitle() routine is
2882           available.
2883
2884       "d_setprotoent_r"
2885           From d_setprotoent_r.U:
2886
2887           This variable conditionally defines the "HAS_SETPROTOENT_R" symbol,
2888           which indicates to the C program that the setprotoent_r() routine
2889           is available.
2890
2891       "d_setpwent"
2892           From d_setpwent.U:
2893
2894           This variable conditionally defines the "HAS_SETPWENT" symbol,
2895           which indicates to the C program that the setpwent() routine is
2896           available for initializing sequential access to the passwd
2897           database.
2898
2899       "d_setpwent_r"
2900           From d_setpwent_r.U:
2901
2902           This variable conditionally defines the "HAS_SETPWENT_R" symbol,
2903           which indicates to the C program that the setpwent_r() routine is
2904           available.
2905
2906       "d_setregid"
2907           From d_setregid.U:
2908
2909           This variable conditionally defines "HAS_SETREGID" if setregid() is
2910           available to change the real and effective gid of the current
2911           process.
2912
2913       "d_setresgid"
2914           From d_setregid.U:
2915
2916           This variable conditionally defines "HAS_SETRESGID" if setresgid()
2917           is available to change the real, effective and saved gid of the
2918           current process.
2919
2920       "d_setresuid"
2921           From d_setreuid.U:
2922
2923           This variable conditionally defines "HAS_SETREUID" if setresuid()
2924           is available to change the real, effective and saved uid of the
2925           current process.
2926
2927       "d_setreuid"
2928           From d_setreuid.U:
2929
2930           This variable conditionally defines "HAS_SETREUID" if setreuid() is
2931           available to change the real and effective uid of the current
2932           process.
2933
2934       "d_setrgid"
2935           From d_setrgid.U:
2936
2937           This variable conditionally defines the "HAS_SETRGID" symbol, which
2938           indicates to the C program that the setrgid() routine is available
2939           to change the real gid of the current program.
2940
2941       "d_setruid"
2942           From d_setruid.U:
2943
2944           This variable conditionally defines the "HAS_SETRUID" symbol, which
2945           indicates to the C program that the setruid() routine is available
2946           to change the real uid of the current program.
2947
2948       "d_setsent"
2949           From d_setsent.U:
2950
2951           This variable conditionally defines "HAS_SETSERVENT" if
2952           setservent() is available.
2953
2954       "d_setservent_r"
2955           From d_setservent_r.U:
2956
2957           This variable conditionally defines the "HAS_SETSERVENT_R" symbol,
2958           which indicates to the C program that the setservent_r() routine is
2959           available.
2960
2961       "d_setsid"
2962           From d_setsid.U:
2963
2964           This variable conditionally defines "HAS_SETSID" if setsid() is
2965           available to set the process group "ID".
2966
2967       "d_setvbuf"
2968           From d_setvbuf.U:
2969
2970           This variable conditionally defines the "HAS_SETVBUF" symbol, which
2971           indicates to the C program that the setvbuf() routine is available
2972           to change buffering on an open stdio stream.
2973
2974       "d_sfio"
2975           From d_sfio.U:
2976
2977           This variable conditionally defines the "USE_SFIO" symbol, and
2978           indicates whether sfio is available (and should be used).
2979
2980       "d_shm"
2981           From d_shm.U:
2982
2983           This variable conditionally defines the "HAS_SHM" symbol, which
2984           indicates that the entire shm*(2) library is present.
2985
2986       "d_shmat"
2987           From d_shmat.U:
2988
2989           This variable conditionally defines the "HAS_SHMAT" symbol, which
2990           indicates to the C program that the shmat() routine is available.
2991
2992       "d_shmatprototype"
2993           From d_shmat.U:
2994
2995           This variable conditionally defines the "HAS_SHMAT_PROTOTYPE"
2996           symbol, which indicates that sys/shm.h has a prototype for shmat.
2997
2998       "d_shmctl"
2999           From d_shmctl.U:
3000
3001           This variable conditionally defines the "HAS_SHMCTL" symbol, which
3002           indicates to the C program that the shmctl() routine is available.
3003
3004       "d_shmdt"
3005           From d_shmdt.U:
3006
3007           This variable conditionally defines the "HAS_SHMDT" symbol, which
3008           indicates to the C program that the shmdt() routine is available.
3009
3010       "d_shmget"
3011           From d_shmget.U:
3012
3013           This variable conditionally defines the "HAS_SHMGET" symbol, which
3014           indicates to the C program that the shmget() routine is available.
3015
3016       "d_sigaction"
3017           From d_sigaction.U:
3018
3019           This variable conditionally defines the "HAS_SIGACTION" symbol,
3020           which indicates that the Vr4 sigaction() routine is available.
3021
3022       "d_signbit"
3023           From d_signbit.U:
3024
3025           This variable conditionally defines the "HAS_SIGNBIT" symbol, which
3026           indicates to the C program that the signbit() routine is available
3027           and safe to use with perl's intern "NV" type.
3028
3029       "d_sigprocmask"
3030           From d_sigprocmask.U:
3031
3032           This variable conditionally defines "HAS_SIGPROCMASK" if
3033           sigprocmask() is available to examine or change the signal mask of
3034           the calling process.
3035
3036       "d_sigsetjmp"
3037           From d_sigsetjmp.U:
3038
3039           This variable conditionally defines the "HAS_SIGSETJMP" symbol,
3040           which indicates that the sigsetjmp() routine is available to call
3041           setjmp() and optionally save the process's signal mask.
3042
3043       "d_sitearch"
3044           From sitearch.U:
3045
3046           This variable conditionally defines "SITEARCH" to hold the pathname
3047           of architecture-dependent library files for $package.  If $sitearch
3048           is the same as $archlib, then this is set to undef.
3049
3050       "d_snprintf"
3051           From d_snprintf.U:
3052
3053           This variable conditionally defines the "HAS_SNPRINTF" symbol,
3054           which indicates to the C program that the snprintf () library
3055           function is available.
3056
3057       "d_sockatmark"
3058           From d_sockatmark.U:
3059
3060           This variable conditionally defines the "HAS_SOCKATMARK" symbol,
3061           which indicates to the C program that the sockatmark() routine is
3062           available.
3063
3064       "d_sockatmarkproto"
3065           From d_sockatmarkproto.U:
3066
3067           This variable conditionally defines the "HAS_SOCKATMARK_PROTO"
3068           symbol, which indicates to the C program that the system provides a
3069           prototype for the sockatmark() function.  Otherwise, it is up to
3070           the program to supply one.
3071
3072       "d_socket"
3073           From d_socket.U:
3074
3075           This variable conditionally defines "HAS_SOCKET", which indicates
3076           that the "BSD" socket interface is supported.
3077
3078       "d_socklen_t"
3079           From d_socklen_t.U:
3080
3081           This symbol will be defined if the C compiler supports socklen_t.
3082
3083       "d_sockpair"
3084           From d_socket.U:
3085
3086           This variable conditionally defines the "HAS_SOCKETPAIR" symbol,
3087           which indicates that the "BSD" socketpair() is supported.
3088
3089       "d_socks5_init"
3090           From d_socks5_init.U:
3091
3092           This variable conditionally defines the HAS_SOCKS5_INIT symbol,
3093           which indicates to the C program that the socks5_init() routine is
3094           available.
3095
3096       "d_sprintf_returns_strlen"
3097           From d_sprintf_len.U:
3098
3099           This variable defines whether sprintf returns the length of the
3100           string (as per the "ANSI" spec). Some C libraries retain
3101           compatibility with pre-"ANSI" C and return a pointer to the passed
3102           in buffer; for these this variable will be undef.
3103
3104       "d_sqrtl"
3105           From d_sqrtl.U:
3106
3107           This variable conditionally defines the "HAS_SQRTL" symbol, which
3108           indicates to the C program that the sqrtl() routine is available.
3109
3110       "d_srand48_r"
3111           From d_srand48_r.U:
3112
3113           This variable conditionally defines the HAS_SRAND48_R symbol, which
3114           indicates to the C program that the srand48_r() routine is
3115           available.
3116
3117       "d_srandom_r"
3118           From d_srandom_r.U:
3119
3120           This variable conditionally defines the "HAS_SRANDOM_R" symbol,
3121           which indicates to the C program that the srandom_r() routine is
3122           available.
3123
3124       "d_sresgproto"
3125           From d_sresgproto.U:
3126
3127           This variable conditionally defines the "HAS_SETRESGID_PROTO"
3128           symbol, which indicates to the C program that the system provides a
3129           prototype for the setresgid() function.  Otherwise, it is up to the
3130           program to supply one.
3131
3132       "d_sresuproto"
3133           From d_sresuproto.U:
3134
3135           This variable conditionally defines the "HAS_SETRESUID_PROTO"
3136           symbol, which indicates to the C program that the system provides a
3137           prototype for the setresuid() function.  Otherwise, it is up to the
3138           program to supply one.
3139
3140       "d_statblks"
3141           From d_statblks.U:
3142
3143           This variable conditionally defines "USE_STAT_BLOCKS" if this
3144           system has a stat structure declaring st_blksize and st_blocks.
3145
3146       "d_statfs_f_flags"
3147           From d_statfs_f_flags.U:
3148
3149           This variable conditionally defines the "HAS_STRUCT_STATFS_F_FLAGS"
3150           symbol, which indicates to struct statfs from has f_flags member.
3151           This kind of struct statfs is coming from sys/mount.h ("BSD"), not
3152           from sys/statfs.h ("SYSV").
3153
3154       "d_statfs_s"
3155           From d_statfs_s.U:
3156
3157           This variable conditionally defines the "HAS_STRUCT_STATFS" symbol,
3158           which indicates that the struct statfs is supported.
3159
3160       "d_statvfs"
3161           From d_statvfs.U:
3162
3163           This variable conditionally defines the "HAS_STATVFS" symbol, which
3164           indicates to the C program that the statvfs() routine is available.
3165
3166       "d_stdio_cnt_lval"
3167           From d_stdstdio.U:
3168
3169           This variable conditionally defines "STDIO_CNT_LVALUE" if the
3170           "FILE_cnt" macro can be used as an lvalue.
3171
3172       "d_stdio_ptr_lval"
3173           From d_stdstdio.U:
3174
3175           This variable conditionally defines "STDIO_PTR_LVALUE" if the
3176           "FILE_ptr" macro can be used as an lvalue.
3177
3178       "d_stdio_ptr_lval_nochange_cnt"
3179           From d_stdstdio.U:
3180
3181           This symbol is defined if using the "FILE_ptr" macro as an lvalue
3182           to increase the pointer by n leaves File_cnt(fp) unchanged.
3183
3184       "d_stdio_ptr_lval_sets_cnt"
3185           From d_stdstdio.U:
3186
3187           This symbol is defined if using the "FILE_ptr" macro as an lvalue
3188           to increase the pointer by n has the side effect of decreasing the
3189           value of File_cnt(fp) by n.
3190
3191       "d_stdio_stream_array"
3192           From stdio_streams.U:
3193
3194           This variable tells whether there is an array holding the stdio
3195           streams.
3196
3197       "d_stdiobase"
3198           From d_stdstdio.U:
3199
3200           This variable conditionally defines "USE_STDIO_BASE" if this system
3201           has a "FILE" structure declaring a usable _base field (or
3202           equivalent) in stdio.h.
3203
3204       "d_stdstdio"
3205           From d_stdstdio.U:
3206
3207           This variable conditionally defines "USE_STDIO_PTR" if this system
3208           has a "FILE" structure declaring usable _ptr and _cnt fields (or
3209           equivalent) in stdio.h.
3210
3211       "d_strchr"
3212           From d_strchr.U:
3213
3214           This variable conditionally defines "HAS_STRCHR" if strchr() and
3215           strrchr() are available for string searching.
3216
3217       "d_strcoll"
3218           From d_strcoll.U:
3219
3220           This variable conditionally defines "HAS_STRCOLL" if strcoll() is
3221           available to compare strings using collating information.
3222
3223       "d_strctcpy"
3224           From d_strctcpy.U:
3225
3226           This variable conditionally defines the "USE_STRUCT_COPY" symbol,
3227           which indicates to the C program that this C compiler knows how to
3228           copy structures.
3229
3230       "d_strerrm"
3231           From d_strerror.U:
3232
3233           This variable holds what Strerrr is defined as to translate an
3234           error code condition into an error message string. It could be
3235           "strerror" or a more "complex" macro emulating strrror with
3236           sys_errlist[], or the "unknown" string when both strerror and
3237           sys_errlist are missing.
3238
3239       "d_strerror"
3240           From d_strerror.U:
3241
3242           This variable conditionally defines "HAS_STRERROR" if strerror() is
3243           available to translate error numbers to strings.
3244
3245       "d_strerror_r"
3246           From d_strerror_r.U:
3247
3248           This variable conditionally defines the "HAS_STRERROR_R" symbol,
3249           which indicates to the C program that the strerror_r() routine is
3250           available.
3251
3252       "d_strftime"
3253           From d_strftime.U:
3254
3255           This variable conditionally defines the "HAS_STRFTIME" symbol,
3256           which indicates to the C program that the strftime() routine is
3257           available.
3258
3259       "d_strlcat"
3260           From d_strlcat.U:
3261
3262           This variable conditionally defines the "HAS_STRLCAT" symbol, which
3263           indicates to the C program that the strlcat () routine is
3264           available.
3265
3266       "d_strlcpy"
3267           From d_strlcpy.U:
3268
3269           This variable conditionally defines the "HAS_STRLCPY" symbol, which
3270           indicates to the C program that the strlcpy () routine is
3271           available.
3272
3273       "d_strtod"
3274           From d_strtod.U:
3275
3276           This variable conditionally defines the "HAS_STRTOD" symbol, which
3277           indicates to the C program that the strtod() routine is available
3278           to provide better numeric string conversion than atof().
3279
3280       "d_strtol"
3281           From d_strtol.U:
3282
3283           This variable conditionally defines the "HAS_STRTOL" symbol, which
3284           indicates to the C program that the strtol() routine is available
3285           to provide better numeric string conversion than atoi() and
3286           friends.
3287
3288       "d_strtold"
3289           From d_strtold.U:
3290
3291           This variable conditionally defines the "HAS_STRTOLD" symbol, which
3292           indicates to the C program that the strtold() routine is available.
3293
3294       "d_strtoll"
3295           From d_strtoll.U:
3296
3297           This variable conditionally defines the "HAS_STRTOLL" symbol, which
3298           indicates to the C program that the strtoll() routine is available.
3299
3300       "d_strtoq"
3301           From d_strtoq.U:
3302
3303           This variable conditionally defines the "HAS_STRTOQ" symbol, which
3304           indicates to the C program that the strtoq() routine is available.
3305
3306       "d_strtoul"
3307           From d_strtoul.U:
3308
3309           This variable conditionally defines the "HAS_STRTOUL" symbol, which
3310           indicates to the C program that the strtoul() routine is available
3311           to provide conversion of strings to unsigned long.
3312
3313       "d_strtoull"
3314           From d_strtoull.U:
3315
3316           This variable conditionally defines the "HAS_STRTOULL" symbol,
3317           which indicates to the C program that the strtoull() routine is
3318           available.
3319
3320       "d_strtouq"
3321           From d_strtouq.U:
3322
3323           This variable conditionally defines the "HAS_STRTOUQ" symbol, which
3324           indicates to the C program that the strtouq() routine is available.
3325
3326       "d_strxfrm"
3327           From d_strxfrm.U:
3328
3329           This variable conditionally defines "HAS_STRXFRM" if strxfrm() is
3330           available to transform strings.
3331
3332       "d_suidsafe"
3333           From d_dosuid.U:
3334
3335           This variable conditionally defines "SETUID_SCRIPTS_ARE_SECURE_NOW"
3336           if setuid scripts can be secure.  This test looks in /dev/fd/.
3337
3338       "d_symlink"
3339           From d_symlink.U:
3340
3341           This variable conditionally defines the "HAS_SYMLINK" symbol, which
3342           indicates to the C program that the symlink() routine is available
3343           to create symbolic links.
3344
3345       "d_syscall"
3346           From d_syscall.U:
3347
3348           This variable conditionally defines "HAS_SYSCALL" if syscall() is
3349           available call arbitrary system calls.
3350
3351       "d_syscallproto"
3352           From d_syscallproto.U:
3353
3354           This variable conditionally defines the "HAS_SYSCALL_PROTO" symbol,
3355           which indicates to the C program that the system provides a
3356           prototype for the syscall() function.  Otherwise, it is up to the
3357           program to supply one.
3358
3359       "d_sysconf"
3360           From d_sysconf.U:
3361
3362           This variable conditionally defines the "HAS_SYSCONF" symbol, which
3363           indicates to the C program that the sysconf() routine is available
3364           to determine system related limits and options.
3365
3366       "d_sysernlst"
3367           From d_strerror.U:
3368
3369           This variable conditionally defines "HAS_SYS_ERRNOLIST" if
3370           sys_errnolist[] is available to translate error numbers to the
3371           symbolic name.
3372
3373       "d_syserrlst"
3374           From d_strerror.U:
3375
3376           This variable conditionally defines "HAS_SYS_ERRLIST" if
3377           sys_errlist[] is available to translate error numbers to strings.
3378
3379       "d_system"
3380           From d_system.U:
3381
3382           This variable conditionally defines "HAS_SYSTEM" if system() is
3383           available to issue a shell command.
3384
3385       "d_tcgetpgrp"
3386           From d_tcgtpgrp.U:
3387
3388           This variable conditionally defines the "HAS_TCGETPGRP" symbol,
3389           which indicates to the C program that the tcgetpgrp() routine is
3390           available.  to get foreground process group "ID".
3391
3392       "d_tcsetpgrp"
3393           From d_tcstpgrp.U:
3394
3395           This variable conditionally defines the "HAS_TCSETPGRP" symbol,
3396           which indicates to the C program that the tcsetpgrp() routine is
3397           available to set foreground process group "ID".
3398
3399       "d_telldir"
3400           From d_readdir.U:
3401
3402           This variable conditionally defines "HAS_TELLDIR" if telldir() is
3403           available.
3404
3405       "d_telldirproto"
3406           From d_telldirproto.U:
3407
3408           This variable conditionally defines the "HAS_TELLDIR_PROTO" symbol,
3409           which indicates to the C program that the system provides a
3410           prototype for the telldir() function.  Otherwise, it is up to the
3411           program to supply one.
3412
3413       "d_time"
3414           From d_time.U:
3415
3416           This variable conditionally defines the "HAS_TIME" symbol, which
3417           indicates that the time() routine exists.  The time() routine is
3418           normaly provided on "UNIX" systems.
3419
3420       "d_timegm"
3421           From d_timegm.U:
3422
3423           This variable conditionally defines the "HAS_TIMEGM" symbol, which
3424           indicates to the C program that the timegm () routine is available.
3425
3426       "d_times"
3427           From d_times.U:
3428
3429           This variable conditionally defines the "HAS_TIMES" symbol, which
3430           indicates that the times() routine exists.  The times() routine is
3431           normaly provided on "UNIX" systems. You may have to include
3432           <sys/times.h>.
3433
3434       "d_tm_tm_gmtoff"
3435           From i_time.U:
3436
3437           This variable conditionally defines "HAS_TM_TM_GMTOFF", which
3438           indicates indicates to the C program that the struct tm has the
3439           tm_gmtoff field.
3440
3441       "d_tm_tm_zone"
3442           From i_time.U:
3443
3444           This variable conditionally defines "HAS_TM_TM_ZONE", which
3445           indicates indicates to the C program that the struct tm has the
3446           tm_zone field.
3447
3448       "d_tmpnam_r"
3449           From d_tmpnam_r.U:
3450
3451           This variable conditionally defines the "HAS_TMPNAM_R" symbol,
3452           which indicates to the C program that the tmpnam_r() routine is
3453           available.
3454
3455       "d_truncate"
3456           From d_truncate.U:
3457
3458           This variable conditionally defines "HAS_TRUNCATE" if truncate() is
3459           available to truncate files.
3460
3461       "d_ttyname_r"
3462           From d_ttyname_r.U:
3463
3464           This variable conditionally defines the "HAS_TTYNAME_R" symbol,
3465           which indicates to the C program that the ttyname_r() routine is
3466           available.
3467
3468       "d_tzname"
3469           From d_tzname.U:
3470
3471           This variable conditionally defines "HAS_TZNAME" if tzname[] is
3472           available to access timezone names.
3473
3474       "d_u32align"
3475           From d_u32align.U:
3476
3477           This variable tells whether you must access character data through
3478           U32-aligned pointers.
3479
3480       "d_ualarm"
3481           From d_ualarm.U:
3482
3483           This variable conditionally defines the "HAS_UALARM" symbol, which
3484           indicates to the C program that the ualarm() routine is available.
3485
3486       "d_umask"
3487           From d_umask.U:
3488
3489           This variable conditionally defines the "HAS_UMASK" symbol, which
3490           indicates to the C program that the umask() routine is available.
3491           to set and get the value of the file creation mask.
3492
3493       "d_uname"
3494           From d_gethname.U:
3495
3496           This variable conditionally defines the "HAS_UNAME" symbol, which
3497           indicates to the C program that the uname() routine may be used to
3498           derive the host name.
3499
3500       "d_union_semun"
3501           From d_union_semun.U:
3502
3503           This variable conditionally defines "HAS_UNION_SEMUN" if the union
3504           semun is defined by including <sys/sem.h>.
3505
3506       "d_unordered"
3507           From d_unordered.U:
3508
3509           This variable conditionally defines the "HAS_UNORDERED" symbol,
3510           which indicates to the C program that the unordered() routine is
3511           available.
3512
3513       "d_unsetenv"
3514           From d_unsetenv.U:
3515
3516           This variable conditionally defines the "HAS_UNSETENV" symbol,
3517           which indicates to the C program that the unsetenv () routine is
3518           available.
3519
3520       "d_usleep"
3521           From d_usleep.U:
3522
3523           This variable conditionally defines "HAS_USLEEP" if usleep() is
3524           available to do high granularity sleeps.
3525
3526       "d_usleepproto"
3527           From d_usleepproto.U:
3528
3529           This variable conditionally defines the "HAS_USLEEP_PROTO" symbol,
3530           which indicates to the C program that the system provides a
3531           prototype for the usleep() function.  Otherwise, it is up to the
3532           program to supply one.
3533
3534       "d_ustat"
3535           From d_ustat.U:
3536
3537           This variable conditionally defines "HAS_USTAT" if ustat() is
3538           available to query file system statistics by dev_t.
3539
3540       "d_vendorarch"
3541           From vendorarch.U:
3542
3543           This variable conditionally defined "PERL_VENDORARCH".
3544
3545       "d_vendorbin"
3546           From vendorbin.U:
3547
3548           This variable conditionally defines "PERL_VENDORBIN".
3549
3550       "d_vendorlib"
3551           From vendorlib.U:
3552
3553           This variable conditionally defines "PERL_VENDORLIB".
3554
3555       "d_vendorscript"
3556           From vendorscript.U:
3557
3558           This variable conditionally defines "PERL_VENDORSCRIPT".
3559
3560       "d_vfork"
3561           From d_vfork.U:
3562
3563           This variable conditionally defines the "HAS_VFORK" symbol, which
3564           indicates the vfork() routine is available.
3565
3566       "d_void_closedir"
3567           From d_closedir.U:
3568
3569           This variable conditionally defines "VOID_CLOSEDIR" if closedir()
3570           does not return a value.
3571
3572       "d_voidsig"
3573           From d_voidsig.U:
3574
3575           This variable conditionally defines "VOIDSIG" if this system
3576           declares "void (*signal(...))()" in signal.h.  The old way was to
3577           declare it as "int (*signal(...))()".
3578
3579       "d_voidtty"
3580           From i_sysioctl.U:
3581
3582           This variable conditionally defines "USE_IOCNOTTY" to indicate that
3583           the ioctl() call with "TIOCNOTTY" should be used to void tty
3584           association.  Otherwise (on "USG" probably), it is enough to close
3585           the standard file decriptors and do a setpgrp().
3586
3587       "d_volatile"
3588           From d_volatile.U:
3589
3590           This variable conditionally defines the "HASVOLATILE" symbol, which
3591           indicates to the C program that this C compiler knows about the
3592           volatile declaration.
3593
3594       "d_vprintf"
3595           From d_vprintf.U:
3596
3597           This variable conditionally defines the "HAS_VPRINTF" symbol, which
3598           indicates to the C program that the vprintf() routine is available
3599           to printf with a pointer to an argument list.
3600
3601       "d_vsnprintf"
3602           From d_snprintf.U:
3603
3604           This variable conditionally defines the "HAS_VSNPRINTF" symbol,
3605           which indicates to the C program that the vsnprintf () library
3606           function is available.
3607
3608       "d_wait4"
3609           From d_wait4.U:
3610
3611           This variable conditionally defines the HAS_WAIT4 symbol, which
3612           indicates the wait4() routine is available.
3613
3614       "d_waitpid"
3615           From d_waitpid.U:
3616
3617           This variable conditionally defines "HAS_WAITPID" if waitpid() is
3618           available to wait for child process.
3619
3620       "d_wcstombs"
3621           From d_wcstombs.U:
3622
3623           This variable conditionally defines the "HAS_WCSTOMBS" symbol,
3624           which indicates to the C program that the wcstombs() routine is
3625           available to convert wide character strings to multibyte strings.
3626
3627       "d_wctomb"
3628           From d_wctomb.U:
3629
3630           This variable conditionally defines the "HAS_WCTOMB" symbol, which
3631           indicates to the C program that the wctomb() routine is available
3632           to convert a wide character to a multibyte.
3633
3634       "d_writev"
3635           From d_writev.U:
3636
3637           This variable conditionally defines the "HAS_WRITEV" symbol, which
3638           indicates to the C program that the writev() routine is available.
3639
3640       "d_xenix"
3641           From Guess.U:
3642
3643           This variable conditionally defines the symbol "XENIX", which
3644           alerts the C program that it runs under Xenix.
3645
3646       "date"
3647           From Loc.U:
3648
3649           This variable is used internally by Configure to determine the full
3650           pathname (if any) of the date program.  After Configure runs, the
3651           value is reset to a plain "date" and is not useful.
3652
3653       "db_hashtype"
3654           From i_db.U:
3655
3656           This variable contains the type of the hash structure element in
3657           the <db.h> header file.  In older versions of "DB", it was int,
3658           while in newer ones it is u_int32_t.
3659
3660       "db_prefixtype"
3661           From i_db.U:
3662
3663           This variable contains the type of the prefix structure element in
3664           the <db.h> header file.  In older versions of "DB", it was int,
3665           while in newer ones it is size_t.
3666
3667       "db_version_major"
3668           From i_db.U:
3669
3670           This variable contains the major version number of Berkeley "DB"
3671           found in the <db.h> header file.
3672
3673       "db_version_minor"
3674           From i_db.U:
3675
3676           This variable contains the minor version number of Berkeley "DB"
3677           found in the <db.h> header file.  For "DB" version 1 this is always
3678           0.
3679
3680       "db_version_patch"
3681           From i_db.U:
3682
3683           This variable contains the patch version number of Berkeley "DB"
3684           found in the <db.h> header file.  For "DB" version 1 this is always
3685           0.
3686
3687       "defvoidused"
3688           From voidflags.U:
3689
3690           This variable contains the default value of the "VOIDUSED" symbol
3691           (15).
3692
3693       "direntrytype"
3694           From i_dirent.U:
3695
3696           This symbol is set to "struct direct" or "struct dirent" depending
3697           on whether dirent is available or not. You should use this pseudo
3698           type to portably declare your directory entries.
3699
3700       "dlext"
3701           From dlext.U:
3702
3703           This variable contains the extension that is to be used for the
3704           dynamically loaded modules that perl generaties.
3705
3706       "dlsrc"
3707           From dlsrc.U:
3708
3709           This variable contains the name of the dynamic loading file that
3710           will be used with the package.
3711
3712       "doublesize"
3713           From doublesize.U:
3714
3715           This variable contains the value of the "DOUBLESIZE" symbol, which
3716           indicates to the C program how many bytes there are in a double.
3717
3718       "drand01"
3719           From randfunc.U:
3720
3721           Indicates the macro to be used to generate normalized random
3722           numbers.  Uses randfunc, often divided by (double) (((unsigned
3723           long) 1 << randbits)) in order to normalize the result.  In C
3724           programs, the macro "Drand01" is mapped to drand01.
3725
3726       "drand48_r_proto"
3727           From d_drand48_r.U:
3728
3729           This variable encodes the prototype of drand48_r.  It is zero if
3730           d_drand48_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
3731           of reentr.h if d_drand48_r is defined.
3732
3733       "dtrace"
3734           From usedtrace.U:
3735
3736           This variable holds the location of the dtrace executable.
3737
3738       "dynamic_ext"
3739           From Extensions.U:
3740
3741           This variable holds a list of "XS" extension files we want to link
3742           dynamically into the package.  It is used by Makefile.
3743
3744   e
3745       "eagain"
3746           From nblock_io.U:
3747
3748           This variable bears the symbolic errno code set by read() when no
3749           data is present on the file and non-blocking I/O was enabled
3750           (otherwise, read() blocks naturally).
3751
3752       "ebcdic"
3753           From ebcdic.U:
3754
3755           This variable conditionally defines "EBCDIC" if this system uses
3756           "EBCDIC" encoding.  Among other things, this means that the
3757           character ranges are not contiguous.  See trnl.U
3758
3759       "echo"
3760           From Loc.U:
3761
3762           This variable is used internally by Configure to determine the full
3763           pathname (if any) of the echo program.  After Configure runs, the
3764           value is reset to a plain "echo" and is not useful.
3765
3766       "egrep"
3767           From Loc.U:
3768
3769           This variable is used internally by Configure to determine the full
3770           pathname (if any) of the egrep program.  After Configure runs, the
3771           value is reset to a plain "egrep" and is not useful.
3772
3773       "emacs"
3774           From Loc.U:
3775
3776           This variable is defined but not used by Configure.  The value is
3777           the empty string and is not useful.
3778
3779       "endgrent_r_proto"
3780           From d_endgrent_r.U:
3781
3782           This variable encodes the prototype of endgrent_r.  It is zero if
3783           d_endgrent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3784           macros of reentr.h if d_endgrent_r is defined.
3785
3786       "endhostent_r_proto"
3787           From d_endhostent_r.U:
3788
3789           This variable encodes the prototype of endhostent_r.  It is zero if
3790           d_endhostent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3791           macros of reentr.h if d_endhostent_r is defined.
3792
3793       "endnetent_r_proto"
3794           From d_endnetent_r.U:
3795
3796           This variable encodes the prototype of endnetent_r.  It is zero if
3797           d_endnetent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3798           macros of reentr.h if d_endnetent_r is defined.
3799
3800       "endprotoent_r_proto"
3801           From d_endprotoent_r.U:
3802
3803           This variable encodes the prototype of endprotoent_r.  It is zero
3804           if d_endprotoent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3805           macros of reentr.h if d_endprotoent_r is defined.
3806
3807       "endpwent_r_proto"
3808           From d_endpwent_r.U:
3809
3810           This variable encodes the prototype of endpwent_r.  It is zero if
3811           d_endpwent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3812           macros of reentr.h if d_endpwent_r is defined.
3813
3814       "endservent_r_proto"
3815           From d_endservent_r.U:
3816
3817           This variable encodes the prototype of endservent_r.  It is zero if
3818           d_endservent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3819           macros of reentr.h if d_endservent_r is defined.
3820
3821       "eunicefix"
3822           From Init.U:
3823
3824           When running under Eunice this variable contains a command which
3825           will convert a shell script to the proper form of text file for it
3826           to be executable by the shell.  On other systems it is a no-op.
3827
3828       "exe_ext"
3829           From Unix.U:
3830
3831           This is an old synonym for _exe.
3832
3833       "expr"
3834           From Loc.U:
3835
3836           This variable is used internally by Configure to determine the full
3837           pathname (if any) of the expr program.  After Configure runs, the
3838           value is reset to a plain "expr" and is not useful.
3839
3840       "extensions"
3841           From Extensions.U:
3842
3843           This variable holds a list of all extension files (both "XS" and
3844           non-xs linked into the package.  It is propagated to Config.pm and
3845           is typically used to test whether a particular extesion is
3846           available.
3847
3848       "extern_C"
3849           From Csym.U:
3850
3851           "ANSI" C requires "extern" where C++ requires 'extern "C"'. This
3852           variable can be used in Configure to do the right thing.
3853
3854       "extras"
3855           From Extras.U:
3856
3857           This variable holds a list of extra modules to install.
3858
3859   f
3860       "fflushall"
3861           From fflushall.U:
3862
3863           This symbol, if defined, tells that to flush all pending stdio
3864           output one must loop through all the stdio file handles stored in
3865           an array and fflush them.  Note that if fflushNULL is defined,
3866           fflushall will not even be probed for and will be left undefined.
3867
3868       "fflushNULL"
3869           From fflushall.U:
3870
3871           This symbol, if defined, tells that fflush("NULL") does flush all
3872           pending stdio output.
3873
3874       "find"
3875           From Loc.U:
3876
3877           This variable is defined but not used by Configure.  The value is
3878           the empty string and is not useful.
3879
3880       "firstmakefile"
3881           From Unix.U:
3882
3883           This variable defines the first file searched by make.  On unix, it
3884           is makefile (then Makefile).  On case-insensitive systems, it might
3885           be something else.  This is only used to deal with convoluted make
3886           depend tricks.
3887
3888       "flex"
3889           From Loc.U:
3890
3891           This variable is defined but not used by Configure.  The value is
3892           the empty string and is not useful.
3893
3894       "fpossize"
3895           From fpossize.U:
3896
3897           This variable contains the size of a fpostype in bytes.
3898
3899       "fpostype"
3900           From fpostype.U:
3901
3902           This variable defines Fpos_t to be something like fpos_t, long,
3903           uint, or whatever type is used to declare file positions in libc.
3904
3905       "freetype"
3906           From mallocsrc.U:
3907
3908           This variable contains the return type of free().  It is usually
3909           void, but occasionally int.
3910
3911       "from"
3912           From Cross.U:
3913
3914           This variable contains the command used by Configure to copy files
3915           from the target host.  Useful and available only during Perl build.
3916           The string ":" if not cross-compiling.
3917
3918       "full_ar"
3919           From Loc_ar.U:
3920
3921           This variable contains the full pathname to "ar", whether or not
3922           the user has specified "portability".  This is only used in the
3923           Makefile.SH.
3924
3925       "full_csh"
3926           From d_csh.U:
3927
3928           This variable contains the full pathname to "csh", whether or not
3929           the user has specified "portability".  This is only used in the
3930           compiled C program, and we assume that all systems which can share
3931           this executable will have the same full pathname to csh.
3932
3933       "full_sed"
3934           From Loc_sed.U:
3935
3936           This variable contains the full pathname to "sed", whether or not
3937           the user has specified "portability".  This is only used in the
3938           compiled C program, and we assume that all systems which can share
3939           this executable will have the same full pathname to sed.
3940
3941   g
3942       "gccansipedantic"
3943           From gccvers.U:
3944
3945           If "GNU" cc (gcc) is used, this variable will enable (if set) the
3946           -ansi and -pedantic ccflags for building core files (through cflags
3947           script). (See Porting/pumpkin.pod for full description).
3948
3949       "gccosandvers"
3950           From gccvers.U:
3951
3952           If "GNU" cc (gcc) is used, this variable holds the operating system
3953           and version used to compile gcc.  It is set to '' if not gcc, or if
3954           nothing useful can be parsed as the os version.
3955
3956       "gccversion"
3957           From gccvers.U:
3958
3959           If "GNU" cc (gcc) is used, this variable holds 1 or 2 to indicate
3960           whether the compiler is version 1 or 2.  This is used in setting
3961           some of the default cflags.  It is set to '' if not gcc.
3962
3963       "getgrent_r_proto"
3964           From d_getgrent_r.U:
3965
3966           This variable encodes the prototype of getgrent_r.  It is zero if
3967           d_getgrent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3968           macros of reentr.h if d_getgrent_r is defined.
3969
3970       "getgrgid_r_proto"
3971           From d_getgrgid_r.U:
3972
3973           This variable encodes the prototype of getgrgid_r.  It is zero if
3974           d_getgrgid_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3975           macros of reentr.h if d_getgrgid_r is defined.
3976
3977       "getgrnam_r_proto"
3978           From d_getgrnam_r.U:
3979
3980           This variable encodes the prototype of getgrnam_r.  It is zero if
3981           d_getgrnam_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
3982           macros of reentr.h if d_getgrnam_r is defined.
3983
3984       "gethostbyaddr_r_proto"
3985           From d_gethostbyaddr_r.U:
3986
3987           This variable encodes the prototype of gethostbyaddr_r.  It is zero
3988           if d_gethostbyaddr_r is undef, and one of the
3989           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_gethostbyaddr_r is
3990           defined.
3991
3992       "gethostbyname_r_proto"
3993           From d_gethostbyname_r.U:
3994
3995           This variable encodes the prototype of gethostbyname_r.  It is zero
3996           if d_gethostbyname_r is undef, and one of the
3997           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_gethostbyname_r is
3998           defined.
3999
4000       "gethostent_r_proto"
4001           From d_gethostent_r.U:
4002
4003           This variable encodes the prototype of gethostent_r.  It is zero if
4004           d_gethostent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4005           macros of reentr.h if d_gethostent_r is defined.
4006
4007       "getlogin_r_proto"
4008           From d_getlogin_r.U:
4009
4010           This variable encodes the prototype of getlogin_r.  It is zero if
4011           d_getlogin_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4012           macros of reentr.h if d_getlogin_r is defined.
4013
4014       "getnetbyaddr_r_proto"
4015           From d_getnetbyaddr_r.U:
4016
4017           This variable encodes the prototype of getnetbyaddr_r.  It is zero
4018           if d_getnetbyaddr_r is undef, and one of the
4019           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getnetbyaddr_r is
4020           defined.
4021
4022       "getnetbyname_r_proto"
4023           From d_getnetbyname_r.U:
4024
4025           This variable encodes the prototype of getnetbyname_r.  It is zero
4026           if d_getnetbyname_r is undef, and one of the
4027           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getnetbyname_r is
4028           defined.
4029
4030       "getnetent_r_proto"
4031           From d_getnetent_r.U:
4032
4033           This variable encodes the prototype of getnetent_r.  It is zero if
4034           d_getnetent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4035           macros of reentr.h if d_getnetent_r is defined.
4036
4037       "getprotobyname_r_proto"
4038           From d_getprotobyname_r.U:
4039
4040           This variable encodes the prototype of getprotobyname_r.  It is
4041           zero if d_getprotobyname_r is undef, and one of the
4042           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getprotobyname_r is
4043           defined.
4044
4045       "getprotobynumber_r_proto"
4046           From d_getprotobynumber_r.U:
4047
4048           This variable encodes the prototype of getprotobynumber_r.  It is
4049           zero if d_getprotobynumber_r is undef, and one of the
4050           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getprotobynumber_r
4051           is defined.
4052
4053       "getprotoent_r_proto"
4054           From d_getprotoent_r.U:
4055
4056           This variable encodes the prototype of getprotoent_r.  It is zero
4057           if d_getprotoent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4058           macros of reentr.h if d_getprotoent_r is defined.
4059
4060       "getpwent_r_proto"
4061           From d_getpwent_r.U:
4062
4063           This variable encodes the prototype of getpwent_r.  It is zero if
4064           d_getpwent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4065           macros of reentr.h if d_getpwent_r is defined.
4066
4067       "getpwnam_r_proto"
4068           From d_getpwnam_r.U:
4069
4070           This variable encodes the prototype of getpwnam_r.  It is zero if
4071           d_getpwnam_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4072           macros of reentr.h if d_getpwnam_r is defined.
4073
4074       "getpwuid_r_proto"
4075           From d_getpwuid_r.U:
4076
4077           This variable encodes the prototype of getpwuid_r.  It is zero if
4078           d_getpwuid_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4079           macros of reentr.h if d_getpwuid_r is defined.
4080
4081       "getservbyname_r_proto"
4082           From d_getservbyname_r.U:
4083
4084           This variable encodes the prototype of getservbyname_r.  It is zero
4085           if d_getservbyname_r is undef, and one of the
4086           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getservbyname_r is
4087           defined.
4088
4089       "getservbyport_r_proto"
4090           From d_getservbyport_r.U:
4091
4092           This variable encodes the prototype of getservbyport_r.  It is zero
4093           if d_getservbyport_r is undef, and one of the
4094           "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getservbyport_r is
4095           defined.
4096
4097       "getservent_r_proto"
4098           From d_getservent_r.U:
4099
4100           This variable encodes the prototype of getservent_r.  It is zero if
4101           d_getservent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4102           macros of reentr.h if d_getservent_r is defined.
4103
4104       "getspnam_r_proto"
4105           From d_getspnam_r.U:
4106
4107           This variable encodes the prototype of getspnam_r.  It is zero if
4108           d_getspnam_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
4109           macros of reentr.h if d_getspnam_r is defined.
4110
4111       "gidformat"
4112           From gidf.U:
4113
4114           This variable contains the format string used for printing a Gid_t.
4115
4116       "gidsign"
4117           From gidsign.U:
4118
4119           This variable contains the signedness of a gidtype.  1 for
4120           unsigned, -1 for signed.
4121
4122       "gidsize"
4123           From gidsize.U:
4124
4125           This variable contains the size of a gidtype in bytes.
4126
4127       "gidtype"
4128           From gidtype.U:
4129
4130           This variable defines Gid_t to be something like gid_t, int,
4131           ushort, or whatever type is used to declare the return type of
4132           getgid().  Typically, it is the type of group ids in the kernel.
4133
4134       "glibpth"
4135           From libpth.U:
4136
4137           This variable holds the general path (space-separated) used to find
4138           libraries.  It may contain directories that do not exist on this
4139           platform, libpth is the cleaned-up version.
4140
4141       "gmake"
4142           From Loc.U:
4143
4144           This variable is used internally by Configure to determine the full
4145           pathname (if any) of the gmake program.  After Configure runs, the
4146           value is reset to a plain "gmake" and is not useful.
4147
4148       "gmtime_r_proto"
4149           From d_gmtime_r.U:
4150
4151           This variable encodes the prototype of gmtime_r.  It is zero if
4152           d_gmtime_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
4153           of reentr.h if d_gmtime_r is defined.
4154
4155       "gnulibc_version"
4156           From d_gnulibc.U:
4157
4158           This variable contains the version number of the "GNU" C library.
4159           It is usually something like 2.2.5.  It is a plain '' if this is
4160           not the "GNU" C library, or if the version is unknown.
4161
4162       "grep"
4163           From Loc.U:
4164
4165           This variable is used internally by Configure to determine the full
4166           pathname (if any) of the grep program.  After Configure runs, the
4167           value is reset to a plain "grep" and is not useful.
4168
4169       "groupcat"
4170           From nis.U:
4171
4172           This variable contains a command that produces the text of the
4173           /etc/group file.  This is normally "cat /etc/group", but can be
4174           "ypcat group" when "NIS" is used.  On some systems, such as os390,
4175           there may be no equivalent command, in which case this variable is
4176           unset.
4177
4178       "groupstype"
4179           From groupstype.U:
4180
4181           This variable defines Groups_t to be something like gid_t, int,
4182           ushort, or whatever type is used for the second argument to
4183           getgroups() and setgroups().  Usually, this is the same as gidtype
4184           (gid_t), but sometimes it isn't.
4185
4186       "gzip"
4187           From Loc.U:
4188
4189           This variable is used internally by Configure to determine the full
4190           pathname (if any) of the gzip program.  After Configure runs, the
4191           value is reset to a plain "gzip" and is not useful.
4192
4193   h
4194       "h_fcntl"
4195           From h_fcntl.U:
4196
4197           This is variable gets set in various places to tell i_fcntl that
4198           <fcntl.h> should be included.
4199
4200       "h_sysfile"
4201           From h_sysfile.U:
4202
4203           This is variable gets set in various places to tell i_sys_file that
4204           <sys/file.h> should be included.
4205
4206       "hint"
4207           From Oldconfig.U:
4208
4209           Gives the type of hints used for previous answers. May be one of
4210           "default", "recommended" or "previous".
4211
4212       "hostcat"
4213           From nis.U:
4214
4215           This variable contains a command that produces the text of the
4216           /etc/hosts file.  This is normally "cat /etc/hosts", but can be
4217           "ypcat hosts" when "NIS" is used.  On some systems, such as os390,
4218           there may be no equivalent command, in which case this variable is
4219           unset.
4220
4221       "html1dir"
4222           From html1dir.U:
4223
4224           This variable contains the name of the directory in which html
4225           source pages are to be put.  This directory is for pages that
4226           describe whole programs, not libraries or modules.  It is intended
4227           to correspond roughly to section 1 of the Unix manuals.
4228
4229       "html1direxp"
4230           From html1dir.U:
4231
4232           This variable is the same as the html1dir variable, but is filename
4233           expanded at configuration time, for convenient use in makefiles.
4234
4235       "html3dir"
4236           From html3dir.U:
4237
4238           This variable contains the name of the directory in which html
4239           source pages are to be put.  This directory is for pages that
4240           describe libraries or modules.  It is intended to correspond
4241           roughly to section 3 of the Unix manuals.
4242
4243       "html3direxp"
4244           From html3dir.U:
4245
4246           This variable is the same as the html3dir variable, but is filename
4247           expanded at configuration time, for convenient use in makefiles.
4248
4249   i
4250       "i16size"
4251           From perlxv.U:
4252
4253           This variable is the size of an I16 in bytes.
4254
4255       "i16type"
4256           From perlxv.U:
4257
4258           This variable contains the C type used for Perl's I16.
4259
4260       "i32size"
4261           From perlxv.U:
4262
4263           This variable is the size of an I32 in bytes.
4264
4265       "i32type"
4266           From perlxv.U:
4267
4268           This variable contains the C type used for Perl's I32.
4269
4270       "i64size"
4271           From perlxv.U:
4272
4273           This variable is the size of an I64 in bytes.
4274
4275       "i64type"
4276           From perlxv.U:
4277
4278           This variable contains the C type used for Perl's I64.
4279
4280       "i8size"
4281           From perlxv.U:
4282
4283           This variable is the size of an I8 in bytes.
4284
4285       "i8type"
4286           From perlxv.U:
4287
4288           This variable contains the C type used for Perl's I8.
4289
4290       "i_arpainet"
4291           From i_arpainet.U:
4292
4293           This variable conditionally defines the "I_ARPA_INET" symbol, and
4294           indicates whether a C program should include <arpa/inet.h>.
4295
4296       "i_assert"
4297           From i_assert.U:
4298
4299           This variable conditionally defines the "I_ASSERT" symbol, which
4300           indicates to the C program that <assert.h> exists and could be
4301           included.
4302
4303       "i_bsdioctl"
4304           From i_sysioctl.U:
4305
4306           This variable conditionally defines the "I_SYS_BSDIOCTL" symbol,
4307           which indicates to the C program that <sys/bsdioctl.h> exists and
4308           should be included.
4309
4310       "i_crypt"
4311           From i_crypt.U:
4312
4313           This variable conditionally defines the "I_CRYPT" symbol, and
4314           indicates whether a C program should include <crypt.h>.
4315
4316       "i_db"
4317           From i_db.U:
4318
4319           This variable conditionally defines the "I_DB" symbol, and
4320           indicates whether a C program may include Berkeley's "DB" include
4321           file <db.h>.
4322
4323       "i_dbm"
4324           From i_dbm.U:
4325
4326           This variable conditionally defines the "I_DBM" symbol, which
4327           indicates to the C program that <dbm.h> exists and should be
4328           included.
4329
4330       "i_dirent"
4331           From i_dirent.U:
4332
4333           This variable conditionally defines "I_DIRENT", which indicates to
4334           the C program that it should include <dirent.h>.
4335
4336       "i_dld"
4337           From i_dld.U:
4338
4339           This variable conditionally defines the "I_DLD" symbol, which
4340           indicates to the C program that <dld.h> ("GNU" dynamic loading)
4341           exists and should be included.
4342
4343       "i_dlfcn"
4344           From i_dlfcn.U:
4345
4346           This variable conditionally defines the "I_DLFCN" symbol, which
4347           indicates to the C program that <dlfcn.h> exists and should be
4348           included.
4349
4350       "i_fcntl"
4351           From i_fcntl.U:
4352
4353           This variable controls the value of "I_FCNTL" (which tells the C
4354           program to include <fcntl.h>).
4355
4356       "i_float"
4357           From i_float.U:
4358
4359           This variable conditionally defines the "I_FLOAT" symbol, and
4360           indicates whether a C program may include <float.h> to get symbols
4361           like "DBL_MAX" or "DBL_MIN", i.e. machine dependent floating point
4362           values.
4363
4364       "i_fp"
4365           From i_fp.U:
4366
4367           This variable conditionally defines the "I_FP" symbol, and
4368           indicates whether a C program should include <fp.h>.
4369
4370       "i_fp_class"
4371           From i_fp_class.U:
4372
4373           This variable conditionally defines the "I_FP_CLASS" symbol, and
4374           indicates whether a C program should include <fp_class.h>.
4375
4376       "i_gdbm"
4377           From i_gdbm.U:
4378
4379           This variable conditionally defines the "I_GDBM" symbol, which
4380           indicates to the C program that <gdbm.h> exists and should be
4381           included.
4382
4383       "i_gdbm_ndbm"
4384           From i_ndbm.U:
4385
4386           This variable conditionally defines the "I_GDBM_NDBM" symbol, which
4387           indicates to the C program that <gdbm-ndbm.h> exists and should be
4388           included.  This is the location of the ndbm.h compatibility file in
4389           Debian 4.0.
4390
4391       "i_gdbmndbm"
4392           From i_ndbm.U:
4393
4394           This variable conditionally defines the "I_GDBMNDBM" symbol, which
4395           indicates to the C program that <gdbm/ndbm.h> exists and should be
4396           included.  This was the location of the ndbm.h compatibility file
4397           in RedHat 7.1.
4398
4399       "i_grp"
4400           From i_grp.U:
4401
4402           This variable conditionally defines the "I_GRP" symbol, and
4403           indicates whether a C program should include <grp.h>.
4404
4405       "i_ieeefp"
4406           From i_ieeefp.U:
4407
4408           This variable conditionally defines the "I_IEEEFP" symbol, and
4409           indicates whether a C program should include <ieeefp.h>.
4410
4411       "i_inttypes"
4412           From i_inttypes.U:
4413
4414           This variable conditionally defines the "I_INTTYPES" symbol, and
4415           indicates whether a C program should include <inttypes.h>.
4416
4417       "i_langinfo"
4418           From i_langinfo.U:
4419
4420           This variable conditionally defines the "I_LANGINFO" symbol, and
4421           indicates whether a C program should include <langinfo.h>.
4422
4423       "i_libutil"
4424           From i_libutil.U:
4425
4426           This variable conditionally defines the "I_LIBUTIL" symbol, and
4427           indicates whether a C program should include <libutil.h>.
4428
4429       "i_limits"
4430           From i_limits.U:
4431
4432           This variable conditionally defines the "I_LIMITS" symbol, and
4433           indicates whether a C program may include <limits.h> to get symbols
4434           like "WORD_BIT" and friends.
4435
4436       "i_locale"
4437           From i_locale.U:
4438
4439           This variable conditionally defines the "I_LOCALE" symbol, and
4440           indicates whether a C program should include <locale.h>.
4441
4442       "i_machcthr"
4443           From i_machcthr.U:
4444
4445           This variable conditionally defines the "I_MACH_CTHREADS" symbol,
4446           and indicates whether a C program should include <mach/cthreads.h>.
4447
4448       "i_malloc"
4449           From i_malloc.U:
4450
4451           This variable conditionally defines the "I_MALLOC" symbol, and
4452           indicates whether a C program should include <malloc.h>.
4453
4454       "i_mallocmalloc"
4455           From i_mallocmalloc.U:
4456
4457           This variable conditionally defines the "I_MALLOCMALLOC" symbol,
4458           and indicates whether a C program should include <malloc/malloc.h>.
4459
4460       "i_math"
4461           From i_math.U:
4462
4463           This variable conditionally defines the "I_MATH" symbol, and
4464           indicates whether a C program may include <math.h>.
4465
4466       "i_memory"
4467           From i_memory.U:
4468
4469           This variable conditionally defines the "I_MEMORY" symbol, and
4470           indicates whether a C program should include <memory.h>.
4471
4472       "i_mntent"
4473           From i_mntent.U:
4474
4475           This variable conditionally defines the "I_MNTENT" symbol, and
4476           indicates whether a C program should include <mntent.h>.
4477
4478       "i_ndbm"
4479           From i_ndbm.U:
4480
4481           This variable conditionally defines the "I_NDBM" symbol, which
4482           indicates to the C program that <ndbm.h> exists and should be
4483           included.
4484
4485       "i_netdb"
4486           From i_netdb.U:
4487
4488           This variable conditionally defines the "I_NETDB" symbol, and
4489           indicates whether a C program should include <netdb.h>.
4490
4491       "i_neterrno"
4492           From i_neterrno.U:
4493
4494           This variable conditionally defines the "I_NET_ERRNO" symbol, which
4495           indicates to the C program that <net/errno.h> exists and should be
4496           included.
4497
4498       "i_netinettcp"
4499           From i_netinettcp.U:
4500
4501           This variable conditionally defines the "I_NETINET_TCP" symbol, and
4502           indicates whether a C program should include <netinet/tcp.h>.
4503
4504       "i_niin"
4505           From i_niin.U:
4506
4507           This variable conditionally defines "I_NETINET_IN", which indicates
4508           to the C program that it should include <netinet/in.h>. Otherwise,
4509           you may try <sys/in.h>.
4510
4511       "i_poll"
4512           From i_poll.U:
4513
4514           This variable conditionally defines the "I_POLL" symbol, and
4515           indicates whether a C program should include <poll.h>.
4516
4517       "i_prot"
4518           From i_prot.U:
4519
4520           This variable conditionally defines the "I_PROT" symbol, and
4521           indicates whether a C program should include <prot.h>.
4522
4523       "i_pthread"
4524           From i_pthread.U:
4525
4526           This variable conditionally defines the "I_PTHREAD" symbol, and
4527           indicates whether a C program should include <pthread.h>.
4528
4529       "i_pwd"
4530           From i_pwd.U:
4531
4532           This variable conditionally defines "I_PWD", which indicates to the
4533           C program that it should include <pwd.h>.
4534
4535       "i_rpcsvcdbm"
4536           From i_dbm.U:
4537
4538           This variable conditionally defines the "I_RPCSVC_DBM" symbol,
4539           which indicates to the C program that <rpcsvc/dbm.h> exists and
4540           should be included.  Some System V systems might need this instead
4541           of <dbm.h>.
4542
4543       "i_sfio"
4544           From i_sfio.U:
4545
4546           This variable conditionally defines the "I_SFIO" symbol, and
4547           indicates whether a C program should include <sfio.h>.
4548
4549       "i_sgtty"
4550           From i_termio.U:
4551
4552           This variable conditionally defines the "I_SGTTY" symbol, which
4553           indicates to the C program that it should include <sgtty.h> rather
4554           than <termio.h>.
4555
4556       "i_shadow"
4557           From i_shadow.U:
4558
4559           This variable conditionally defines the "I_SHADOW" symbol, and
4560           indicates whether a C program should include <shadow.h>.
4561
4562       "i_socks"
4563           From i_socks.U:
4564
4565           This variable conditionally defines the "I_SOCKS" symbol, and
4566           indicates whether a C program should include <socks.h>.
4567
4568       "i_stdarg"
4569           From i_varhdr.U:
4570
4571           This variable conditionally defines the "I_STDARG" symbol, which
4572           indicates to the C program that <stdarg.h> exists and should be
4573           included.
4574
4575       "i_stddef"
4576           From i_stddef.U:
4577
4578           This variable conditionally defines the "I_STDDEF" symbol, which
4579           indicates to the C program that <stddef.h> exists and should be
4580           included.
4581
4582       "i_stdlib"
4583           From i_stdlib.U:
4584
4585           This variable conditionally defines the "I_STDLIB" symbol, which
4586           indicates to the C program that <stdlib.h> exists and should be
4587           included.
4588
4589       "i_string"
4590           From i_string.U:
4591
4592           This variable conditionally defines the "I_STRING" symbol, which
4593           indicates that <string.h> should be included rather than
4594           <strings.h>.
4595
4596       "i_sunmath"
4597           From i_sunmath.U:
4598
4599           This variable conditionally defines the "I_SUNMATH" symbol, and
4600           indicates whether a C program should include <sunmath.h>.
4601
4602       "i_sysaccess"
4603           From i_sysaccess.U:
4604
4605           This variable conditionally defines the "I_SYS_ACCESS" symbol, and
4606           indicates whether a C program should include <sys/access.h>.
4607
4608       "i_sysdir"
4609           From i_sysdir.U:
4610
4611           This variable conditionally defines the "I_SYS_DIR" symbol, and
4612           indicates whether a C program should include <sys/dir.h>.
4613
4614       "i_sysfile"
4615           From i_sysfile.U:
4616
4617           This variable conditionally defines the "I_SYS_FILE" symbol, and
4618           indicates whether a C program should include <sys/file.h> to get
4619           "R_OK" and friends.
4620
4621       "i_sysfilio"
4622           From i_sysioctl.U:
4623
4624           This variable conditionally defines the "I_SYS_FILIO" symbol, which
4625           indicates to the C program that <sys/filio.h> exists and should be
4626           included in preference to <sys/ioctl.h>.
4627
4628       "i_sysin"
4629           From i_niin.U:
4630
4631           This variable conditionally defines "I_SYS_IN", which indicates to
4632           the C program that it should include <sys/in.h> instead of
4633           <netinet/in.h>.
4634
4635       "i_sysioctl"
4636           From i_sysioctl.U:
4637
4638           This variable conditionally defines the "I_SYS_IOCTL" symbol, which
4639           indicates to the C program that <sys/ioctl.h> exists and should be
4640           included.
4641
4642       "i_syslog"
4643           From i_syslog.U:
4644
4645           This variable conditionally defines the "I_SYSLOG" symbol, and
4646           indicates whether a C program should include <syslog.h>.
4647
4648       "i_sysmman"
4649           From i_sysmman.U:
4650
4651           This variable conditionally defines the "I_SYS_MMAN" symbol, and
4652           indicates whether a C program should include <sys/mman.h>.
4653
4654       "i_sysmode"
4655           From i_sysmode.U:
4656
4657           This variable conditionally defines the "I_SYSMODE" symbol, and
4658           indicates whether a C program should include <sys/mode.h>.
4659
4660       "i_sysmount"
4661           From i_sysmount.U:
4662
4663           This variable conditionally defines the "I_SYSMOUNT" symbol, and
4664           indicates whether a C program should include <sys/mount.h>.
4665
4666       "i_sysndir"
4667           From i_sysndir.U:
4668
4669           This variable conditionally defines the "I_SYS_NDIR" symbol, and
4670           indicates whether a C program should include <sys/ndir.h>.
4671
4672       "i_sysparam"
4673           From i_sysparam.U:
4674
4675           This variable conditionally defines the "I_SYS_PARAM" symbol, and
4676           indicates whether a C program should include <sys/param.h>.
4677
4678       "i_syspoll"
4679           From i_syspoll.U:
4680
4681           This variable conditionally defines the "I_SYS_POLL" symbol, which
4682           indicates to the C program that it should include <sys/poll.h>.
4683
4684       "i_sysresrc"
4685           From i_sysresrc.U:
4686
4687           This variable conditionally defines the "I_SYS_RESOURCE" symbol,
4688           and indicates whether a C program should include <sys/resource.h>.
4689
4690       "i_syssecrt"
4691           From i_syssecrt.U:
4692
4693           This variable conditionally defines the "I_SYS_SECURITY" symbol,
4694           and indicates whether a C program should include <sys/security.h>.
4695
4696       "i_sysselct"
4697           From i_sysselct.U:
4698
4699           This variable conditionally defines "I_SYS_SELECT", which indicates
4700           to the C program that it should include <sys/select.h> in order to
4701           get the definition of struct timeval.
4702
4703       "i_syssockio"
4704           From i_sysioctl.U:
4705
4706           This variable conditionally defines "I_SYS_SOCKIO" to indicate to
4707           the C program that socket ioctl codes may be found in
4708           <sys/sockio.h> instead of <sys/ioctl.h>.
4709
4710       "i_sysstat"
4711           From i_sysstat.U:
4712
4713           This variable conditionally defines the "I_SYS_STAT" symbol, and
4714           indicates whether a C program should include <sys/stat.h>.
4715
4716       "i_sysstatfs"
4717           From i_sysstatfs.U:
4718
4719           This variable conditionally defines the "I_SYSSTATFS" symbol, and
4720           indicates whether a C program should include <sys/statfs.h>.
4721
4722       "i_sysstatvfs"
4723           From i_sysstatvfs.U:
4724
4725           This variable conditionally defines the "I_SYSSTATVFS" symbol, and
4726           indicates whether a C program should include <sys/statvfs.h>.
4727
4728       "i_systime"
4729           From i_time.U:
4730
4731           This variable conditionally defines "I_SYS_TIME", which indicates
4732           to the C program that it should include <sys/time.h>.
4733
4734       "i_systimek"
4735           From i_time.U:
4736
4737           This variable conditionally defines "I_SYS_TIME_KERNEL", which
4738           indicates to the C program that it should include <sys/time.h> with
4739           "KERNEL" defined.
4740
4741       "i_systimes"
4742           From i_systimes.U:
4743
4744           This variable conditionally defines the "I_SYS_TIMES" symbol, and
4745           indicates whether a C program should include <sys/times.h>.
4746
4747       "i_systypes"
4748           From i_systypes.U:
4749
4750           This variable conditionally defines the "I_SYS_TYPES" symbol, and
4751           indicates whether a C program should include <sys/types.h>.
4752
4753       "i_sysuio"
4754           From i_sysuio.U:
4755
4756           This variable conditionally defines the "I_SYSUIO" symbol, and
4757           indicates whether a C program should include <sys/uio.h>.
4758
4759       "i_sysun"
4760           From i_sysun.U:
4761
4762           This variable conditionally defines "I_SYS_UN", which indicates to
4763           the C program that it should include <sys/un.h> to get "UNIX"
4764           domain socket definitions.
4765
4766       "i_sysutsname"
4767           From i_sysutsname.U:
4768
4769           This variable conditionally defines the "I_SYSUTSNAME" symbol, and
4770           indicates whether a C program should include <sys/utsname.h>.
4771
4772       "i_sysvfs"
4773           From i_sysvfs.U:
4774
4775           This variable conditionally defines the "I_SYSVFS" symbol, and
4776           indicates whether a C program should include <sys/vfs.h>.
4777
4778       "i_syswait"
4779           From i_syswait.U:
4780
4781           This variable conditionally defines "I_SYS_WAIT", which indicates
4782           to the C program that it should include <sys/wait.h>.
4783
4784       "i_termio"
4785           From i_termio.U:
4786
4787           This variable conditionally defines the "I_TERMIO" symbol, which
4788           indicates to the C program that it should include <termio.h> rather
4789           than <sgtty.h>.
4790
4791       "i_termios"
4792           From i_termio.U:
4793
4794           This variable conditionally defines the "I_TERMIOS" symbol, which
4795           indicates to the C program that the "POSIX" <termios.h> file is to
4796           be included.
4797
4798       "i_time"
4799           From i_time.U:
4800
4801           This variable conditionally defines "I_TIME", which indicates to
4802           the C program that it should include <time.h>.
4803
4804       "i_unistd"
4805           From i_unistd.U:
4806
4807           This variable conditionally defines the "I_UNISTD" symbol, and
4808           indicates whether a C program should include <unistd.h>.
4809
4810       "i_ustat"
4811           From i_ustat.U:
4812
4813           This variable conditionally defines the "I_USTAT" symbol, and
4814           indicates whether a C program should include <ustat.h>.
4815
4816       "i_utime"
4817           From i_utime.U:
4818
4819           This variable conditionally defines the "I_UTIME" symbol, and
4820           indicates whether a C program should include <utime.h>.
4821
4822       "i_values"
4823           From i_values.U:
4824
4825           This variable conditionally defines the "I_VALUES" symbol, and
4826           indicates whether a C program may include <values.h> to get symbols
4827           like "MAXLONG" and friends.
4828
4829       "i_varargs"
4830           From i_varhdr.U:
4831
4832           This variable conditionally defines "I_VARARGS", which indicates to
4833           the C program that it should include <varargs.h>.
4834
4835       "i_varhdr"
4836           From i_varhdr.U:
4837
4838           Contains the name of the header to be included to get va_dcl
4839           definition.  Typically one of varargs.h or stdarg.h.
4840
4841       "i_vfork"
4842           From i_vfork.U:
4843
4844           This variable conditionally defines the "I_VFORK" symbol, and
4845           indicates whether a C program should include vfork.h.
4846
4847       "ignore_versioned_solibs"
4848           From libs.U:
4849
4850           This variable should be non-empty if non-versioned shared libraries
4851           (libfoo.so.x.y) are to be ignored (because they cannot be linked
4852           against).
4853
4854       "inc_version_list"
4855           From inc_version_list.U:
4856
4857           This variable specifies the list of subdirectories in over which
4858           perl.c:incpush() and lib/lib.pm will automatically search when
4859           adding directories to @"INC".  The elements in the list are
4860           separated by spaces.  This is only useful if you have a perl
4861           library directory tree structured like the default one.  See
4862           "INSTALL" for how this works.  The versioned site_perl directory
4863           was introduced in 5.005, so that is the lowest possible value.
4864
4865           This list includes architecture-dependent directories back to
4866           version $api_versionstring (e.g. 5.5.640) and architecture-
4867           independent directories all the way back to 5.005.
4868
4869       "inc_version_list_init"
4870           From inc_version_list.U:
4871
4872           This variable holds the same list as inc_version_list, but each
4873           item is enclosed in double quotes and separated by commas, suitable
4874           for use in the "PERL_INC_VERSION_LIST" initialization.
4875
4876       "incpath"
4877           From usrinc.U:
4878
4879           This variable must preceed the normal include path to get hte right
4880           one, as in $incpath/usr/include or $incpath/usr/lib.  Value can be
4881           "" or /bsd43 on mips.
4882
4883       "inews"
4884           From Loc.U:
4885
4886           This variable is defined but not used by Configure.  The value is
4887           the empty string and is not useful.
4888
4889       "initialinstalllocation"
4890           From bin.U:
4891
4892           When userelocatableinc is true, this variable holds the location
4893           that make install should copy the perl binary to, with all the run-
4894           time relocatable paths calculated from this at install time.  When
4895           used, it is initialised to the original value of binexp, and then
4896           binexp is set to .../, as the other binaries are found relative to
4897           the perl binary.
4898
4899       "installarchlib"
4900           From archlib.U:
4901
4902           This variable is really the same as archlibexp but may differ on
4903           those systems using "AFS". For extra portability, only this
4904           variable should be used in makefiles.
4905
4906       "installbin"
4907           From bin.U:
4908
4909           This variable is the same as binexp unless "AFS" is running in
4910           which case the user is explicitely prompted for it. This variable
4911           should always be used in your makefiles for maximum portability.
4912
4913       "installhtml1dir"
4914           From html1dir.U:
4915
4916           This variable is really the same as html1direxp, unless you are
4917           using a different installprefix.  For extra portability, you should
4918           only use this variable within your makefiles.
4919
4920       "installhtml3dir"
4921           From html3dir.U:
4922
4923           This variable is really the same as html3direxp, unless you are
4924           using a different installprefix.  For extra portability, you should
4925           only use this variable within your makefiles.
4926
4927       "installman1dir"
4928           From man1dir.U:
4929
4930           This variable is really the same as man1direxp, unless you are
4931           using "AFS" in which case it points to the read/write location
4932           whereas man1direxp only points to the read-only access location.
4933           For extra portability, you should only use this variable within
4934           your makefiles.
4935
4936       "installman3dir"
4937           From man3dir.U:
4938
4939           This variable is really the same as man3direxp, unless you are
4940           using "AFS" in which case it points to the read/write location
4941           whereas man3direxp only points to the read-only access location.
4942           For extra portability, you should only use this variable within
4943           your makefiles.
4944
4945       "installprefix"
4946           From installprefix.U:
4947
4948           This variable holds the name of the directory below which "make
4949           install" will install the package.  For most users, this is the
4950           same as prefix.  However, it is useful for installing the software
4951           into a different (usually temporary) location after which it can be
4952           bundled up and moved somehow to the final location specified by
4953           prefix.
4954
4955       "installprefixexp"
4956           From installprefix.U:
4957
4958           This variable holds the full absolute path of installprefix with
4959           all ~-expansion done.
4960
4961       "installprivlib"
4962           From privlib.U:
4963
4964           This variable is really the same as privlibexp but may differ on
4965           those systems using "AFS". For extra portability, only this
4966           variable should be used in makefiles.
4967
4968       "installscript"
4969           From scriptdir.U:
4970
4971           This variable is usually the same as scriptdirexp, unless you are
4972           on a system running "AFS", in which case they may differ slightly.
4973           You should always use this variable within your makefiles for
4974           portability.
4975
4976       "installsitearch"
4977           From sitearch.U:
4978
4979           This variable is really the same as sitearchexp but may differ on
4980           those systems using "AFS". For extra portability, only this
4981           variable should be used in makefiles.
4982
4983       "installsitebin"
4984           From sitebin.U:
4985
4986           This variable is usually the same as sitebinexp, unless you are on
4987           a system running "AFS", in which case they may differ slightly. You
4988           should always use this variable within your makefiles for
4989           portability.
4990
4991       "installsitehtml1dir"
4992           From sitehtml1dir.U:
4993
4994           This variable is really the same as sitehtml1direxp, unless you are
4995           using "AFS" in which case it points to the read/write location
4996           whereas html1direxp only points to the read-only access location.
4997           For extra portability, you should only use this variable within
4998           your makefiles.
4999
5000       "installsitehtml3dir"
5001           From sitehtml3dir.U:
5002
5003           This variable is really the same as sitehtml3direxp, unless you are
5004           using "AFS" in which case it points to the read/write location
5005           whereas html3direxp only points to the read-only access location.
5006           For extra portability, you should only use this variable within
5007           your makefiles.
5008
5009       "installsitelib"
5010           From sitelib.U:
5011
5012           This variable is really the same as sitelibexp but may differ on
5013           those systems using "AFS". For extra portability, only this
5014           variable should be used in makefiles.
5015
5016       "installsiteman1dir"
5017           From siteman1dir.U:
5018
5019           This variable is really the same as siteman1direxp, unless you are
5020           using "AFS" in which case it points to the read/write location
5021           whereas man1direxp only points to the read-only access location.
5022           For extra portability, you should only use this variable within
5023           your makefiles.
5024
5025       "installsiteman3dir"
5026           From siteman3dir.U:
5027
5028           This variable is really the same as siteman3direxp, unless you are
5029           using "AFS" in which case it points to the read/write location
5030           whereas man3direxp only points to the read-only access location.
5031           For extra portability, you should only use this variable within
5032           your makefiles.
5033
5034       "installsitescript"
5035           From sitescript.U:
5036
5037           This variable is usually the same as sitescriptexp, unless you are
5038           on a system running "AFS", in which case they may differ slightly.
5039           You should always use this variable within your makefiles for
5040           portability.
5041
5042       "installstyle"
5043           From installstyle.U:
5044
5045           This variable describes the "style" of the perl installation.  This
5046           is intended to be useful for tools that need to manipulate entire
5047           perl distributions.  Perl itself doesn't use this to find its
5048           libraries -- the library directories are stored directly in
5049           Config.pm.  Currently, there are only two styles:  "lib" and
5050           lib/perl5.  The default library locations (e.g. privlib, sitelib)
5051           are either $prefix/lib or $prefix/lib/perl5.  The former is useful
5052           if $prefix is a directory dedicated to perl (e.g. /opt/perl), while
5053           the latter is useful if $prefix is shared by many packages, e.g. if
5054           $prefix=/usr/local.
5055
5056           Unfortunately, while this "style" variable is used to set defaults
5057           for all three directory hierarchies (core, vendor, and site), there
5058           is no guarantee that the same style is actually appropriate for all
5059           those directories.  For example, $prefix might be /opt/perl, but
5060           $siteprefix might be /usr/local.  (Perhaps, in retrospect, the
5061           "lib" style should never have been supported, but it did seem like
5062           a nice idea at the time.)
5063
5064           The situation is even less clear for tools such as MakeMaker that
5065           can be used to install additional modules into non-standard places.
5066           For example, if a user intends to install a module into a private
5067           directory (perhaps by setting "PREFIX" on the Makefile.PL command
5068           line), then there is no reason to assume that the Configure-time
5069           $installstyle setting will be relevant for that "PREFIX".
5070
5071           This may later be extended to include other information, so be
5072           careful with pattern-matching on the results.
5073
5074           For compatibility with perl5.005 and earlier, the default setting
5075           is based on whether or not $prefix contains the string "perl".
5076
5077       "installusrbinperl"
5078           From instubperl.U:
5079
5080           This variable tells whether Perl should be installed also as
5081           /usr/bin/perl in addition to $installbin/perl
5082
5083       "installvendorarch"
5084           From vendorarch.U:
5085
5086           This variable is really the same as vendorarchexp but may differ on
5087           those systems using "AFS". For extra portability, only this
5088           variable should be used in makefiles.
5089
5090       "installvendorbin"
5091           From vendorbin.U:
5092
5093           This variable is really the same as vendorbinexp but may differ on
5094           those systems using "AFS". For extra portability, only this
5095           variable should be used in makefiles.
5096
5097       "installvendorhtml1dir"
5098           From vendorhtml1dir.U:
5099
5100           This variable is really the same as vendorhtml1direxp but may
5101           differ on those systems using "AFS". For extra portability, only
5102           this variable should be used in makefiles.
5103
5104       "installvendorhtml3dir"
5105           From vendorhtml3dir.U:
5106
5107           This variable is really the same as vendorhtml3direxp but may
5108           differ on those systems using "AFS". For extra portability, only
5109           this variable should be used in makefiles.
5110
5111       "installvendorlib"
5112           From vendorlib.U:
5113
5114           This variable is really the same as vendorlibexp but may differ on
5115           those systems using "AFS". For extra portability, only this
5116           variable should be used in makefiles.
5117
5118       "installvendorman1dir"
5119           From vendorman1dir.U:
5120
5121           This variable is really the same as vendorman1direxp but may differ
5122           on those systems using "AFS". For extra portability, only this
5123           variable should be used in makefiles.
5124
5125       "installvendorman3dir"
5126           From vendorman3dir.U:
5127
5128           This variable is really the same as vendorman3direxp but may differ
5129           on those systems using "AFS". For extra portability, only this
5130           variable should be used in makefiles.
5131
5132       "installvendorscript"
5133           From vendorscript.U:
5134
5135           This variable is really the same as vendorscriptexp but may differ
5136           on those systems using "AFS". For extra portability, only this
5137           variable should be used in makefiles.
5138
5139       "intsize"
5140           From intsize.U:
5141
5142           This variable contains the value of the "INTSIZE" symbol, which
5143           indicates to the C program how many bytes there are in an int.
5144
5145       "issymlink"
5146           From issymlink.U:
5147
5148           This variable holds the test command to test for a symbolic link
5149           (if they are supported).  Typical values include "test -h" and
5150           "test -L".
5151
5152       "ivdformat"
5153           From perlxvf.U:
5154
5155           This variable contains the format string used for printing a Perl
5156           "IV" as a signed decimal integer.
5157
5158       "ivsize"
5159           From perlxv.U:
5160
5161           This variable is the size of an "IV" in bytes.
5162
5163       "ivtype"
5164           From perlxv.U:
5165
5166           This variable contains the C type used for Perl's "IV".
5167
5168   k
5169       "known_extensions"
5170           From Extensions.U:
5171
5172           This variable holds a list of all "XS" extensions included in the
5173           package.
5174
5175       "ksh"
5176           From Loc.U:
5177
5178           This variable is defined but not used by Configure.  The value is
5179           the empty string and is not useful.
5180
5181   l
5182       "ld"
5183           From dlsrc.U:
5184
5185           This variable indicates the program to be used to link libraries
5186           for dynamic loading.  On some systems, it is "ld".  On "ELF"
5187           systems, it should be $cc.  Mostly, we'll try to respect the hint
5188           file setting.
5189
5190       "lddlflags"
5191           From dlsrc.U:
5192
5193           This variable contains any special flags that might need to be
5194           passed to $ld to create a shared library suitable for dynamic
5195           loading.  It is up to the makefile to use it.  For hpux, it should
5196           be "-b".  For sunos 4.1, it is empty.
5197
5198       "ldflags"
5199           From ccflags.U:
5200
5201           This variable contains any additional C loader flags desired by the
5202           user.  It is up to the Makefile to use this.
5203
5204       "ldflags_uselargefiles"
5205           From uselfs.U:
5206
5207           This variable contains the loader flags needed by large file builds
5208           and added to ldflags by hints files.
5209
5210       "ldlibpthname"
5211           From libperl.U:
5212
5213           This variable holds the name of the shared library search path,
5214           often "LD_LIBRARY_PATH".  To get an empty string, the hints file
5215           must set this to "none".
5216
5217       "less"
5218           From Loc.U:
5219
5220           This variable is used internally by Configure to determine the full
5221           pathname (if any) of the less program.  After Configure runs, the
5222           value is reset to a plain "less" and is not useful.
5223
5224       "lib_ext"
5225           From Unix.U:
5226
5227           This is an old synonym for _a.
5228
5229       "libc"
5230           From libc.U:
5231
5232           This variable contains the location of the C library.
5233
5234       "libperl"
5235           From libperl.U:
5236
5237           The perl executable is obtained by linking perlmain.c with libperl,
5238           any static extensions (usually just DynaLoader), and any other
5239           libraries needed on this system.  libperl is usually libperl.a, but
5240           can also be libperl.so.xxx if the user wishes to build a perl
5241           executable with a shared library.
5242
5243       "libpth"
5244           From libpth.U:
5245
5246           This variable holds the general path (space-separated) used to find
5247           libraries. It is intended to be used by other units.
5248
5249       "libs"
5250           From libs.U:
5251
5252           This variable holds the additional libraries we want to use.  It is
5253           up to the Makefile to deal with it.  The list can be empty.
5254
5255       "libsdirs"
5256           From libs.U:
5257
5258           This variable holds the directory names aka dirnames of the
5259           libraries we found and accepted, duplicates are removed.
5260
5261       "libsfiles"
5262           From libs.U:
5263
5264           This variable holds the filenames aka basenames of the libraries we
5265           found and accepted.
5266
5267       "libsfound"
5268           From libs.U:
5269
5270           This variable holds the full pathnames of the libraries we found
5271           and accepted.
5272
5273       "libspath"
5274           From libs.U:
5275
5276           This variable holds the directory names probed for libraries.
5277
5278       "libswanted"
5279           From Myinit.U:
5280
5281           This variable holds a list of all the libraries we want to search.
5282           The order is chosen to pick up the c library ahead of ucb or bsd
5283           libraries for SVR4.
5284
5285       "libswanted_uselargefiles"
5286           From uselfs.U:
5287
5288           This variable contains the libraries needed by large file builds
5289           and added to ldflags by hints files.  It is a space separated list
5290           of the library names without the "lib" prefix or any suffix, just
5291           like libswanted..
5292
5293       "line"
5294           From Loc.U:
5295
5296           This variable is defined but not used by Configure.  The value is
5297           the empty string and is not useful.
5298
5299       "lint"
5300           From Loc.U:
5301
5302           This variable is defined but not used by Configure.  The value is
5303           the empty string and is not useful.
5304
5305       "lkflags"
5306           From ccflags.U:
5307
5308           This variable contains any additional C partial linker flags
5309           desired by the user.  It is up to the Makefile to use this.
5310
5311       "ln"
5312           From Loc.U:
5313
5314           This variable is used internally by Configure to determine the full
5315           pathname (if any) of the ln program.  After Configure runs, the
5316           value is reset to a plain "ln" and is not useful.
5317
5318       "lns"
5319           From lns.U:
5320
5321           This variable holds the name of the command to make symbolic links
5322           (if they are supported).  It can be used in the Makefile. It is
5323           either "ln -s" or "ln"
5324
5325       "localtime_r_proto"
5326           From d_localtime_r.U:
5327
5328           This variable encodes the prototype of localtime_r.  It is zero if
5329           d_localtime_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
5330           macros of reentr.h if d_localtime_r is defined.
5331
5332       "locincpth"
5333           From ccflags.U:
5334
5335           This variable contains a list of additional directories to be
5336           searched by the compiler.  The appropriate "-I" directives will be
5337           added to ccflags.  This is intended to simplify setting local
5338           directories from the Configure command line.  It's not much, but it
5339           parallels the loclibpth stuff in libpth.U.
5340
5341       "loclibpth"
5342           From libpth.U:
5343
5344           This variable holds the paths (space-separated) used to find local
5345           libraries.  It is prepended to libpth, and is intended to be easily
5346           set from the command line.
5347
5348       "longdblsize"
5349           From d_longdbl.U:
5350
5351           This variable contains the value of the "LONG_DOUBLESIZE" symbol,
5352           which indicates to the C program how many bytes there are in a long
5353           double, if this system supports long doubles.
5354
5355       "longlongsize"
5356           From d_longlong.U:
5357
5358           This variable contains the value of the "LONGLONGSIZE" symbol,
5359           which indicates to the C program how many bytes there are in a long
5360           long, if this system supports long long.
5361
5362       "longsize"
5363           From intsize.U:
5364
5365           This variable contains the value of the "LONGSIZE" symbol, which
5366           indicates to the C program how many bytes there are in a long.
5367
5368       "lp"
5369           From Loc.U:
5370
5371           This variable is defined but not used by Configure.  The value is
5372           the empty string and is not useful.
5373
5374       "lpr"
5375           From Loc.U:
5376
5377           This variable is defined but not used by Configure.  The value is
5378           the empty string and is not useful.
5379
5380       "ls"
5381           From Loc.U:
5382
5383           This variable is used internally by Configure to determine the full
5384           pathname (if any) of the ls program.  After Configure runs, the
5385           value is reset to a plain "ls" and is not useful.
5386
5387       "lseeksize"
5388           From lseektype.U:
5389
5390           This variable defines lseektype to be something like off_t, long,
5391           or whatever type is used to declare lseek offset's type in the
5392           kernel (which also appears to be lseek's return type).
5393
5394       "lseektype"
5395           From lseektype.U:
5396
5397           This variable defines lseektype to be something like off_t, long,
5398           or whatever type is used to declare lseek offset's type in the
5399           kernel (which also appears to be lseek's return type).
5400
5401   m
5402       "mad"
5403           From mad.U:
5404
5405           This variable indicates that the Misc Attribute Definition code is
5406           to be compiled.
5407
5408       "madlyh"
5409           From mad.U:
5410
5411           If the Misc Attribute Decoration is to be compiled, this variable
5412           is set to the name of the extra header files to be used, else it is
5413           ''
5414
5415       "madlyobj"
5416           From mad.U:
5417
5418           If the Misc Attribute Decoration is to be compiled, this variable
5419           is set to the name of the extra object files to be used, else it is
5420           ''
5421
5422       "madlysrc"
5423           From mad.U:
5424
5425           If the Misc Attribute Decoration is to be compiled, this variable
5426           is set to the name of the extra C source files to be used, else it
5427           is ''
5428
5429       "mail"
5430           From Loc.U:
5431
5432           This variable is defined but not used by Configure.  The value is
5433           the empty string and is not useful.
5434
5435       "mailx"
5436           From Loc.U:
5437
5438           This variable is defined but not used by Configure.  The value is
5439           the empty string and is not useful.
5440
5441       "make"
5442           From Loc.U:
5443
5444           This variable is used internally by Configure to determine the full
5445           pathname (if any) of the make program.  After Configure runs, the
5446           value is reset to a plain "make" and is not useful.
5447
5448       "make_set_make"
5449           From make.U:
5450
5451           Some versions of "make" set the variable "MAKE".  Others do not.
5452           This variable contains the string to be included in Makefile.SH so
5453           that "MAKE" is set if needed, and not if not needed.  Possible
5454           values are:
5455
5456           make_set_make="#"        # If your make program handles this for
5457           you,
5458
5459           make_set_make="MAKE=$make"    # if it doesn't.
5460
5461           This uses a comment character so that we can distinguish a "set"
5462           value (from a previous config.sh or Configure "-D" option) from an
5463           uncomputed value.
5464
5465       "mallocobj"
5466           From mallocsrc.U:
5467
5468           This variable contains the name of the malloc.o that this package
5469           generates, if that malloc.o is preferred over the system malloc.
5470           Otherwise the value is null.  This variable is intended for
5471           generating Makefiles.  See mallocsrc.
5472
5473       "mallocsrc"
5474           From mallocsrc.U:
5475
5476           This variable contains the name of the malloc.c that comes with the
5477           package, if that malloc.c is preferred over the system malloc.
5478           Otherwise the value is null.  This variable is intended for
5479           generating Makefiles.
5480
5481       "malloctype"
5482           From mallocsrc.U:
5483
5484           This variable contains the kind of ptr returned by malloc and
5485           realloc.
5486
5487       "man1dir"
5488           From man1dir.U:
5489
5490           This variable contains the name of the directory in which manual
5491           source pages are to be put.  It is the responsibility of the
5492           Makefile.SH to get the value of this into the proper command.  You
5493           must be prepared to do the ~name expansion yourself.
5494
5495       "man1direxp"
5496           From man1dir.U:
5497
5498           This variable is the same as the man1dir variable, but is filename
5499           expanded at configuration time, for convenient use in makefiles.
5500
5501       "man1ext"
5502           From man1dir.U:
5503
5504           This variable contains the extension that the manual page should
5505           have: one of "n", "l", or 1.  The Makefile must supply the ..  See
5506           man1dir.
5507
5508       "man3dir"
5509           From man3dir.U:
5510
5511           This variable contains the name of the directory in which manual
5512           source pages are to be put.  It is the responsibility of the
5513           Makefile.SH to get the value of this into the proper command.  You
5514           must be prepared to do the ~name expansion yourself.
5515
5516       "man3direxp"
5517           From man3dir.U:
5518
5519           This variable is the same as the man3dir variable, but is filename
5520           expanded at configuration time, for convenient use in makefiles.
5521
5522       "man3ext"
5523           From man3dir.U:
5524
5525           This variable contains the extension that the manual page should
5526           have: one of "n", "l", or 3.  The Makefile must supply the ..  See
5527           man3dir.
5528
5529       "mips_type"
5530           From usrinc.U:
5531
5532           This variable holds the environment type for the mips system.
5533           Possible values are "BSD 4.3" and "System V".
5534
5535       "mistrustnm"
5536           From Csym.U:
5537
5538           This variable can be used to establish a fallthrough for the cases
5539           where nm fails to find a symbol.  If usenm is false or usenm is
5540           true and mistrustnm is false, this variable has no effect.  If
5541           usenm is true and mistrustnm is "compile", a test program will be
5542           compiled to try to find any symbol that can't be located via nm
5543           lookup.  If mistrustnm is "run", the test program will be run as
5544           well as being compiled.
5545
5546       "mkdir"
5547           From Loc.U:
5548
5549           This variable is used internally by Configure to determine the full
5550           pathname (if any) of the mkdir program.  After Configure runs, the
5551           value is reset to a plain "mkdir" and is not useful.
5552
5553       "mmaptype"
5554           From d_mmap.U:
5555
5556           This symbol contains the type of pointer returned by mmap() (and
5557           simultaneously the type of the first argument).  It can be "void *"
5558           or "caddr_t".
5559
5560       "modetype"
5561           From modetype.U:
5562
5563           This variable defines modetype to be something like mode_t, int,
5564           unsigned short, or whatever type is used to declare file modes for
5565           system calls.
5566
5567       "more"
5568           From Loc.U:
5569
5570           This variable is used internally by Configure to determine the full
5571           pathname (if any) of the more program.  After Configure runs, the
5572           value is reset to a plain "more" and is not useful.
5573
5574       "multiarch"
5575           From multiarch.U:
5576
5577           This variable conditionally defines the "MULTIARCH" symbol which
5578           signifies the presence of multiplatform files.  This is normally
5579           set by hints files.
5580
5581       "mv"
5582           From Loc.U:
5583
5584           This variable is defined but not used by Configure.  The value is
5585           the empty string and is not useful.
5586
5587       "myarchname"
5588           From archname.U:
5589
5590           This variable holds the architecture name computed by Configure in
5591           a previous run. It is not intended to be perused by any user and
5592           should never be set in a hint file.
5593
5594       "mydomain"
5595           From myhostname.U:
5596
5597           This variable contains the eventual value of the "MYDOMAIN" symbol,
5598           which is the domain of the host the program is going to run on.
5599           The domain must be appended to myhostname to form a complete host
5600           name.  The dot comes with mydomain, and need not be supplied by the
5601           program.
5602
5603       "myhostname"
5604           From myhostname.U:
5605
5606           This variable contains the eventual value of the "MYHOSTNAME"
5607           symbol, which is the name of the host the program is going to run
5608           on.  The domain is not kept with hostname, but must be gotten from
5609           mydomain.  The dot comes with mydomain, and need not be supplied by
5610           the program.
5611
5612       "myuname"
5613           From Oldconfig.U:
5614
5615           The output of "uname -a" if available, otherwise the hostname. On
5616           Xenix, pseudo variables assignments in the output are stripped,
5617           thank you. The whole thing is then lower-cased.
5618
5619   n
5620       "n" From n.U:
5621
5622           This variable contains the "-n" flag if that is what causes the
5623           echo command to suppress newline.  Otherwise it is null.  Correct
5624           usage is $echo $n "prompt for a question: $c".
5625
5626       "need_va_copy"
5627           From need_va_copy.U:
5628
5629           This symbol, if defined, indicates that the system stores the
5630           variable argument list datatype, va_list, in a format that cannot
5631           be copied by simple assignment, so that some other means must be
5632           used when copying is required.  As such systems vary in their
5633           provision (or non-provision) of copying mechanisms, handy.h defines
5634           a platform- "independent" macro, Perl_va_copy(src, dst), to do the
5635           job.
5636
5637       "netdb_hlen_type"
5638           From netdbtype.U:
5639
5640           This variable holds the type used for the 2nd argument to
5641           gethostbyaddr().  Usually, this is int or size_t or unsigned.  This
5642           is only useful if you have gethostbyaddr(), naturally.
5643
5644       "netdb_host_type"
5645           From netdbtype.U:
5646
5647           This variable holds the type used for the 1st argument to
5648           gethostbyaddr().  Usually, this is char * or void *,  possibly with
5649           or without a const prefix.  This is only useful if you have
5650           gethostbyaddr(), naturally.
5651
5652       "netdb_name_type"
5653           From netdbtype.U:
5654
5655           This variable holds the type used for the argument to
5656           gethostbyname().  Usually, this is char * or const char *.  This is
5657           only useful if you have gethostbyname(), naturally.
5658
5659       "netdb_net_type"
5660           From netdbtype.U:
5661
5662           This variable holds the type used for the 1st argument to
5663           getnetbyaddr().  Usually, this is int or long.  This is only useful
5664           if you have getnetbyaddr(), naturally.
5665
5666       "nm"
5667           From Loc.U:
5668
5669           This variable is used internally by Configure to determine the full
5670           pathname (if any) of the nm program.  After Configure runs, the
5671           value is reset to a plain "nm" and is not useful.
5672
5673       "nm_opt"
5674           From usenm.U:
5675
5676           This variable holds the options that may be necessary for nm.
5677
5678       "nm_so_opt"
5679           From usenm.U:
5680
5681           This variable holds the options that may be necessary for nm to
5682           work on a shared library but that can not be used on an archive
5683           library.  Currently, this is only used by Linux, where nm --dynamic
5684           is *required* to get symbols from an "ELF" library which has been
5685           stripped, but nm --dynamic is *fatal* on an archive library.  Maybe
5686           Linux should just always set usenm=false.
5687
5688       "nonxs_ext"
5689           From Extensions.U:
5690
5691           This variable holds a list of all non-xs extensions included in the
5692           package.  All of them will be built.
5693
5694       "nroff"
5695           From Loc.U:
5696
5697           This variable is used internally by Configure to determine the full
5698           pathname (if any) of the nroff program.  After Configure runs, the
5699           value is reset to a plain "nroff" and is not useful.
5700
5701       "nv_overflows_integers_at"
5702           From perlxv.U:
5703
5704           This variable gives the largest integer value that NVs can hold as
5705           a constant floating point expression.  If it could not be
5706           determined, it holds the value 0.
5707
5708       "nv_preserves_uv_bits"
5709           From perlxv.U:
5710
5711           This variable indicates how many of bits type uvtype a variable
5712           nvtype can preserve.
5713
5714       "nveformat"
5715           From perlxvf.U:
5716
5717           This variable contains the format string used for printing a Perl
5718           "NV" using %e-ish floating point format.
5719
5720       "nvEUformat"
5721           From perlxvf.U:
5722
5723           This variable contains the format string used for printing a Perl
5724           "NV" using %E-ish floating point format.
5725
5726       "nvfformat"
5727           From perlxvf.U:
5728
5729           This variable confains the format string used for printing a Perl
5730           "NV" using %f-ish floating point format.
5731
5732       "nvFUformat"
5733           From perlxvf.U:
5734
5735           This variable confains the format string used for printing a Perl
5736           "NV" using %F-ish floating point format.
5737
5738       "nvgformat"
5739           From perlxvf.U:
5740
5741           This variable contains the format string used for printing a Perl
5742           "NV" using %g-ish floating point format.
5743
5744       "nvGUformat"
5745           From perlxvf.U:
5746
5747           This variable contains the format string used for printing a Perl
5748           "NV" using %G-ish floating point format.
5749
5750       "nvsize"
5751           From perlxv.U:
5752
5753           This variable is the size of an "NV" in bytes.
5754
5755       "nvtype"
5756           From perlxv.U:
5757
5758           This variable contains the C type used for Perl's "NV".
5759
5760   o
5761       "o_nonblock"
5762           From nblock_io.U:
5763
5764           This variable bears the symbol value to be used during open() or
5765           fcntl() to turn on non-blocking I/O for a file descriptor. If you
5766           wish to switch between blocking and non-blocking, you may try
5767           ioctl("FIOSNBIO") instead, but that is only supported by some
5768           devices.
5769
5770       "obj_ext"
5771           From Unix.U:
5772
5773           This is an old synonym for _o.
5774
5775       "old_pthread_create_joinable"
5776           From d_pthrattrj.U:
5777
5778           This variable defines the constant to use for creating joinable
5779           (aka undetached) pthreads.  Unused if pthread.h defines
5780           "PTHREAD_CREATE_JOINABLE".  If used, possible values are
5781           "PTHREAD_CREATE_UNDETACHED" and "__UNDETACHED".
5782
5783       "optimize"
5784           From ccflags.U:
5785
5786           This variable contains any optimizer/debugger flag that should be
5787           used.  It is up to the Makefile to use it.
5788
5789       "orderlib"
5790           From orderlib.U:
5791
5792           This variable is "true" if the components of libraries must be
5793           ordered (with `lorder $* | tsort`) before placing them in an
5794           archive.  Set to "false" if ranlib or ar can generate random
5795           libraries.
5796
5797       "osname"
5798           From Oldconfig.U:
5799
5800           This variable contains the operating system name (e.g. sunos,
5801           solaris, hpux, etc.).  It can be useful later on for setting
5802           defaults.  Any spaces are replaced with underscores.  It is set to
5803           a null string if we can't figure it out.
5804
5805       "osvers"
5806           From Oldconfig.U:
5807
5808           This variable contains the operating system version (e.g.  4.1.3,
5809           5.2, etc.).  It is primarily used for helping select an appropriate
5810           hints file, but might be useful elsewhere for setting defaults.  It
5811           is set to '' if we can't figure it out.  We try to be flexible
5812           about how much of the version number to keep, e.g. if 4.1.1, 4.1.2,
5813           and 4.1.3 are essentially the same for this package, hints files
5814           might just be os_4.0 or os_4.1, etc., not keeping separate files
5815           for each little release.
5816
5817       "otherlibdirs"
5818           From otherlibdirs.U:
5819
5820           This variable contains a colon-separated set of paths for the perl
5821           binary to search for additional library files or modules.  These
5822           directories will be tacked to the end of @"INC".  Perl will
5823           automatically search below each path for version- and architecture-
5824           specific directories.  See inc_version_list for more details.  A
5825           value of " " means "none" and is used to preserve this value for
5826           the next run through Configure.
5827
5828   p
5829       "package"
5830           From package.U:
5831
5832           This variable contains the name of the package being constructed.
5833           It is primarily intended for the use of later Configure units.
5834
5835       "pager"
5836           From pager.U:
5837
5838           This variable contains the name of the preferred pager on the
5839           system.  Usual values are (the full pathnames of) more, less, pg,
5840           or cat.
5841
5842       "passcat"
5843           From nis.U:
5844
5845           This variable contains a command that produces the text of the
5846           /etc/passwd file.  This is normally "cat /etc/passwd", but can be
5847           "ypcat passwd" when "NIS" is used.  On some systems, such as os390,
5848           there may be no equivalent command, in which case this variable is
5849           unset.
5850
5851       "patchlevel"
5852           From patchlevel.U:
5853
5854           The patchlevel level of this package.  The value of patchlevel
5855           comes from the patchlevel.h file.  In a version number such as
5856           5.6.1, this is the 6.  In patchlevel.h, this is referred to as
5857           "PERL_VERSION".
5858
5859       "path_sep"
5860           From Unix.U:
5861
5862           This is an old synonym for p_ in Head.U, the character used to
5863           separate elements in the command shell search "PATH".
5864
5865       "perl"
5866           From Loc.U:
5867
5868           This variable is defined but not used by Configure.  The value is
5869           the empty string and is not useful.
5870
5871       "perl5"
5872           From perl5.U:
5873
5874           This variable contains the full path (if any) to a previously
5875           installed perl5.005 or later suitable for running the script to
5876           determine inc_version_list.
5877
5878   P
5879       "PERL_API_REVISION"
5880           From patchlevel.h:
5881
5882           This number describes the earliest compatible "PERL_REVISION" of
5883           Perl ("compatibility" here being defined as sufficient binary/"API"
5884           compatibility to run "XS" code built with the older version).
5885           Normally this does not change across maintenance releases.  Please
5886           read the comment in patchlevel.h.
5887
5888       "PERL_API_SUBVERSION"
5889           From patchlevel.h:
5890
5891           This number describes the earliest compatible "PERL_SUBVERSION" of
5892           Perl ("compatibility" here being defined as sufficient binary/"API"
5893           compatibility to run "XS" code built with the older version).
5894           Normally this does not change across maintenance releases.  Please
5895           read the comment in patchlevel.h.
5896
5897       "PERL_API_VERSION"
5898           From patchlevel.h:
5899
5900           This number describes the earliest compatible "PERL_VERSION" of
5901           Perl ("compatibility" here being defined as sufficient binary/"API"
5902           compatibility to run "XS" code built with the older version).
5903           Normally this does not change across maintenance releases.  Please
5904           read the comment in patchlevel.h.
5905
5906       "PERL_CONFIG_SH"
5907           From Oldsyms.U:
5908
5909           This is set to "true" in config.sh so that a shell script sourcing
5910           config.sh can tell if it has been sourced already.
5911
5912       "PERL_PATCHLEVEL"
5913           From Oldsyms.U:
5914
5915           This symbol reflects the patchlevel, if available. Will usually
5916           come from the .patch file, which is available when the perl source
5917           tree was fetched with rsync.
5918
5919       "perl_patchlevel"
5920           From patchlevel.U:
5921
5922           This is the Perl patch level, a numeric change identifier, as
5923           defined by whichever source code maintenance system is used to
5924           maintain the patches; currently Perforce.  It does not correlate
5925           with the Perl version numbers or the maintenance versus development
5926           dichotomy except by also being increasing.
5927
5928       "PERL_REVISION"
5929           From Oldsyms.U:
5930
5931           In a Perl version number such as 5.6.2, this is the 5.  This value
5932           is manually set in patchlevel.h
5933
5934       "PERL_SUBVERSION"
5935           From Oldsyms.U:
5936
5937           In a Perl version number such as 5.6.2, this is the 2.  Values
5938           greater than 50 represent potentially unstable development
5939           subversions.  This value is manually set in patchlevel.h
5940
5941       "PERL_VERSION"
5942           From Oldsyms.U:
5943
5944           In a Perl version number such as 5.6.2, this is the 6.  This value
5945           is manually set in patchlevel.h
5946
5947       "perladmin"
5948           From perladmin.U:
5949
5950           Electronic mail address of the perl5 administrator.
5951
5952       "perllibs"
5953           From End.U:
5954
5955           The list of libraries needed by Perl only (any libraries needed by
5956           extensions only will by dropped, if using dynamic loading).
5957
5958       "perlpath"
5959           From perlpath.U:
5960
5961           This variable contains the eventual value of the "PERLPATH" symbol,
5962           which contains the name of the perl interpreter to be used in shell
5963           scripts and in the "eval "exec"" idiom.  This variable is not
5964           necessarily the pathname of the file containing the perl
5965           interpreter; you must append the executable extension (_exe) if it
5966           is not already present.  Note that Perl code that runs during the
5967           Perl build process cannot reference this variable, as Perl may not
5968           have been installed, or even if installed, may be a different
5969           version of Perl.
5970
5971       "pg"
5972           From Loc.U:
5973
5974           This variable is used internally by Configure to determine the full
5975           pathname (if any) of the pg program.  After Configure runs, the
5976           value is reset to a plain "pg" and is not useful.
5977
5978       "phostname"
5979           From myhostname.U:
5980
5981           This variable contains the eventual value of the "PHOSTNAME"
5982           symbol, which is a command that can be fed to popen() to get the
5983           host name.  The program should probably not presume that the domain
5984           is or isn't there already.
5985
5986       "pidtype"
5987           From pidtype.U:
5988
5989           This variable defines "PIDTYPE" to be something like pid_t, int,
5990           ushort, or whatever type is used to declare process ids in the
5991           kernel.
5992
5993       "plibpth"
5994           From libpth.U:
5995
5996           Holds the private path used by Configure to find out the libraries.
5997           Its value is prepend to libpth. This variable takes care of special
5998           machines, like the mips.  Usually, it should be empty.
5999
6000       "pmake"
6001           From Loc.U:
6002
6003           This variable is defined but not used by Configure.  The value is
6004           the empty string and is not useful.
6005
6006       "pr"
6007           From Loc.U:
6008
6009           This variable is defined but not used by Configure.  The value is
6010           the empty string and is not useful.
6011
6012       "prefix"
6013           From prefix.U:
6014
6015           This variable holds the name of the directory below which the user
6016           will install the package.  Usually, this is /usr/local, and
6017           executables go in /usr/local/bin, library stuff in /usr/local/lib,
6018           man pages in /usr/local/man, etc.  It is only used to set defaults
6019           for things in bin.U, mansrc.U, privlib.U, or scriptdir.U.
6020
6021       "prefixexp"
6022           From prefix.U:
6023
6024           This variable holds the full absolute path of the directory below
6025           which the user will install the package.  Derived from prefix.
6026
6027       "privlib"
6028           From privlib.U:
6029
6030           This variable contains the eventual value of the "PRIVLIB" symbol,
6031           which is the name of the private library for this package.  It may
6032           have a ~ on the front. It is up to the makefile to eventually
6033           create this directory while performing installation (with ~
6034           substitution).
6035
6036       "privlibexp"
6037           From privlib.U:
6038
6039           This variable is the ~name expanded version of privlib, so that you
6040           may use it directly in Makefiles or shell scripts.
6041
6042       "procselfexe"
6043           From d_procselfexe.U:
6044
6045           If d_procselfexe is defined, $procselfexe is the filename of the
6046           symbolic link pointing to the absolute pathname of the executing
6047           program.
6048
6049       "prototype"
6050           From prototype.U:
6051
6052           This variable holds the eventual value of "CAN_PROTOTYPE", which
6053           indicates the C compiler can handle funciton prototypes.
6054
6055       "ptrsize"
6056           From ptrsize.U:
6057
6058           This variable contains the value of the "PTRSIZE" symbol, which
6059           indicates to the C program how many bytes there are in a pointer.
6060
6061   q
6062       "quadkind"
6063           From quadtype.U:
6064
6065           This variable, if defined, encodes the type of a quad: 1 = int, 2 =
6066           long, 3 = long long, 4 = int64_t.
6067
6068       "quadtype"
6069           From quadtype.U:
6070
6071           This variable defines Quad_t to be something like long, int, long
6072           long, int64_t, or whatever type is used for 64-bit integers.
6073
6074   r
6075       "randbits"
6076           From randfunc.U:
6077
6078           Indicates how many bits are produced by the function used to
6079           generate normalized random numbers.
6080
6081       "randfunc"
6082           From randfunc.U:
6083
6084           Indicates the name of the random number function to use.  Values
6085           include drand48, random, and rand. In C programs, the "Drand01"
6086           macro is defined to generate uniformly distributed random numbers
6087           over the range [0., 1.[ (see drand01 and nrand).
6088
6089       "random_r_proto"
6090           From d_random_r.U:
6091
6092           This variable encodes the prototype of random_r.  It is zero if
6093           d_random_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
6094           of reentr.h if d_random_r is defined.
6095
6096       "randseedtype"
6097           From randfunc.U:
6098
6099           Indicates the type of the argument of the seedfunc.
6100
6101       "ranlib"
6102           From orderlib.U:
6103
6104           This variable is set to the pathname of the ranlib program, if it
6105           is needed to generate random libraries.  Set to ":" if ar can
6106           generate random libraries or if random libraries are not supported
6107
6108       "rd_nodata"
6109           From nblock_io.U:
6110
6111           This variable holds the return code from read() when no data is
6112           present. It should be -1, but some systems return 0 when "O_NDELAY"
6113           is used, which is a shame because you cannot make the difference
6114           between no data and an EOF.. Sigh!
6115
6116       "readdir64_r_proto"
6117           From d_readdir64_r.U:
6118
6119           This variable encodes the prototype of readdir64_r.  It is zero if
6120           d_readdir64_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6121           macros of reentr.h if d_readdir64_r is defined.
6122
6123       "readdir_r_proto"
6124           From d_readdir_r.U:
6125
6126           This variable encodes the prototype of readdir_r.  It is zero if
6127           d_readdir_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
6128           of reentr.h if d_readdir_r is defined.
6129
6130       "revision"
6131           From patchlevel.U:
6132
6133           The value of revision comes from the patchlevel.h file.  In a
6134           version number such as 5.6.1, this is the 5.  In patchlevel.h, this
6135           is referred to as "PERL_REVISION".
6136
6137       "rm"
6138           From Loc.U:
6139
6140           This variable is used internally by Configure to determine the full
6141           pathname (if any) of the rm program.  After Configure runs, the
6142           value is reset to a plain "rm" and is not useful.
6143
6144       "rm_try"
6145           From Unix.U:
6146
6147           This is a cleanup variable for try test programs.  Internal
6148           Configure use only.
6149
6150       "rmail"
6151           From Loc.U:
6152
6153           This variable is defined but not used by Configure.  The value is
6154           the empty string and is not useful.
6155
6156       "run"
6157           From Cross.U:
6158
6159           This variable contains the command used by Configure to copy and
6160           execute a cross-compiled executable in the target host.  Useful and
6161           available only during Perl build.  Empty string '' if not cross-
6162           compiling.
6163
6164       "runnm"
6165           From usenm.U:
6166
6167           This variable contains "true" or "false" depending whether the nm
6168           extraction should be performed or not, according to the value of
6169           usenm and the flags on the Configure command line.
6170
6171   s
6172       "sched_yield"
6173           From d_pthread_y.U:
6174
6175           This variable defines the way to yield the execution of the current
6176           thread.
6177
6178       "scriptdir"
6179           From scriptdir.U:
6180
6181           This variable holds the name of the directory in which the user
6182           wants to put publicly scripts for the package in question.  It is
6183           either the same directory as for binaries, or a special one that
6184           can be mounted across different architectures, like /usr/share.
6185           Programs must be prepared to deal with ~name expansion.
6186
6187       "scriptdirexp"
6188           From scriptdir.U:
6189
6190           This variable is the same as scriptdir, but is filename expanded at
6191           configuration time, for programs not wanting to bother with it.
6192
6193       "sed"
6194           From Loc.U:
6195
6196           This variable is used internally by Configure to determine the full
6197           pathname (if any) of the sed program.  After Configure runs, the
6198           value is reset to a plain "sed" and is not useful.
6199
6200       "seedfunc"
6201           From randfunc.U:
6202
6203           Indicates the random number generating seed function.  Values
6204           include srand48, srandom, and srand.
6205
6206       "selectminbits"
6207           From selectminbits.U:
6208
6209           This variable holds the minimum number of bits operated by select.
6210           That is, if you do select(n, ...), how many bits at least will be
6211           cleared in the masks if some activity is detected.  Usually this is
6212           either n or 32*ceil(n/32), especially many little-endians do the
6213           latter.  This is only useful if you have select(), naturally.
6214
6215       "selecttype"
6216           From selecttype.U:
6217
6218           This variable holds the type used for the 2nd, 3rd, and 4th
6219           arguments to select.  Usually, this is "fd_set *", if "HAS_FD_SET"
6220           is defined, and "int *" otherwise.  This is only useful if you have
6221           select(), naturally.
6222
6223       "sendmail"
6224           From Loc.U:
6225
6226           This variable is defined but not used by Configure.  The value is
6227           the empty string and is not useful.
6228
6229       "setgrent_r_proto"
6230           From d_setgrent_r.U:
6231
6232           This variable encodes the prototype of setgrent_r.  It is zero if
6233           d_setgrent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6234           macros of reentr.h if d_setgrent_r is defined.
6235
6236       "sethostent_r_proto"
6237           From d_sethostent_r.U:
6238
6239           This variable encodes the prototype of sethostent_r.  It is zero if
6240           d_sethostent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6241           macros of reentr.h if d_sethostent_r is defined.
6242
6243       "setlocale_r_proto"
6244           From d_setlocale_r.U:
6245
6246           This variable encodes the prototype of setlocale_r.  It is zero if
6247           d_setlocale_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6248           macros of reentr.h if d_setlocale_r is defined.
6249
6250       "setnetent_r_proto"
6251           From d_setnetent_r.U:
6252
6253           This variable encodes the prototype of setnetent_r.  It is zero if
6254           d_setnetent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6255           macros of reentr.h if d_setnetent_r is defined.
6256
6257       "setprotoent_r_proto"
6258           From d_setprotoent_r.U:
6259
6260           This variable encodes the prototype of setprotoent_r.  It is zero
6261           if d_setprotoent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6262           macros of reentr.h if d_setprotoent_r is defined.
6263
6264       "setpwent_r_proto"
6265           From d_setpwent_r.U:
6266
6267           This variable encodes the prototype of setpwent_r.  It is zero if
6268           d_setpwent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6269           macros of reentr.h if d_setpwent_r is defined.
6270
6271       "setservent_r_proto"
6272           From d_setservent_r.U:
6273
6274           This variable encodes the prototype of setservent_r.  It is zero if
6275           d_setservent_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6276           macros of reentr.h if d_setservent_r is defined.
6277
6278       "sGMTIME_max"
6279           From time_size.U:
6280
6281           This variable defines the maximum value of the time_t offset that
6282           the system function gmtime () accepts
6283
6284       "sGMTIME_min"
6285           From time_size.U:
6286
6287           This variable defines the minimum value of the time_t offset that
6288           the system function gmtime () accepts
6289
6290       "sh"
6291           From sh.U:
6292
6293           This variable contains the full pathname of the shell used on this
6294           system to execute Bourne shell scripts.  Usually, this will be
6295           /bin/sh, though it's possible that some systems will have /bin/ksh,
6296           /bin/pdksh, /bin/ash, /bin/bash, or even something such as
6297           D:/bin/sh.exe.  This unit comes before Options.U, so you can't set
6298           sh with a "-D" option, though you can override this (and startsh)
6299           with "-O -Dsh=/bin/whatever -Dstartsh=whatever"
6300
6301       "shar"
6302           From Loc.U:
6303
6304           This variable is defined but not used by Configure.  The value is
6305           the empty string and is not useful.
6306
6307       "sharpbang"
6308           From spitshell.U:
6309
6310           This variable contains the string #! if this system supports that
6311           construct.
6312
6313       "shmattype"
6314           From d_shmat.U:
6315
6316           This symbol contains the type of pointer returned by shmat().  It
6317           can be "void *" or "char *".
6318
6319       "shortsize"
6320           From intsize.U:
6321
6322           This variable contains the value of the "SHORTSIZE" symbol which
6323           indicates to the C program how many bytes there are in a short.
6324
6325       "shrpenv"
6326           From libperl.U:
6327
6328           If the user builds a shared libperl.so, then we need to tell the
6329           "perl" executable where it will be able to find the installed
6330           libperl.so.  One way to do this on some systems is to set the
6331           environment variable "LD_RUN_PATH" to the directory that will be
6332           the final location of the shared libperl.so.  The makefile can use
6333           this with something like $shrpenv $("CC") -o perl perlmain.o
6334           $libperl $libs Typical values are shrpenv="env
6335           "LD_RUN_PATH"=$archlibexp/"CORE"" or shrpenv='' See the main perl
6336           Makefile.SH for actual working usage.  Alternatively, we might be
6337           able to use a command line option such as -R $archlibexp/"CORE"
6338           (Solaris) or -Wl,-rpath $archlibexp/"CORE" (Linux).
6339
6340       "shsharp"
6341           From spitshell.U:
6342
6343           This variable tells further Configure units whether your sh can
6344           handle # comments.
6345
6346       "sig_count"
6347           From sig_name.U:
6348
6349           This variable holds a number larger than the largest valid signal
6350           number.  This is usually the same as the "NSIG" macro.
6351
6352       "sig_name"
6353           From sig_name.U:
6354
6355           This variable holds the signal names, space separated. The leading
6356           "SIG" in signal name is removed.  A "ZERO" is prepended to the
6357           list.  This is currently not used, sig_name_init is used instead.
6358
6359       "sig_name_init"
6360           From sig_name.U:
6361
6362           This variable holds the signal names, enclosed in double quotes and
6363           separated by commas, suitable for use in the "SIG_NAME" definition
6364           below.  A "ZERO" is prepended to the list, and the list is
6365           terminated with a plain 0.  The leading "SIG" in signal names is
6366           removed. See sig_num.
6367
6368       "sig_num"
6369           From sig_name.U:
6370
6371           This variable holds the signal numbers, space separated. A "ZERO"
6372           is prepended to the list (corresponding to the fake "SIGZERO").
6373           Those numbers correspond to  the value of the signal listed in the
6374           same place within the sig_name list.  This is currently not used,
6375           sig_num_init is used instead.
6376
6377       "sig_num_init"
6378           From sig_name.U:
6379
6380           This variable holds the signal numbers, enclosed in double quotes
6381           and separated by commas, suitable for use in the "SIG_NUM"
6382           definition below.  A "ZERO" is prepended to the list, and the list
6383           is terminated with a plain 0.
6384
6385       "sig_size"
6386           From sig_name.U:
6387
6388           This variable contains the number of elements of the sig_name and
6389           sig_num arrays.
6390
6391       "signal_t"
6392           From d_voidsig.U:
6393
6394           This variable holds the type of the signal handler (void or int).
6395
6396       "sitearch"
6397           From sitearch.U:
6398
6399           This variable contains the eventual value of the "SITEARCH" symbol,
6400           which is the name of the private library for this package.  It may
6401           have a ~ on the front. It is up to the makefile to eventually
6402           create this directory while performing installation (with ~
6403           substitution).  The standard distribution will put nothing in this
6404           directory.  After perl has been installed, users may install their
6405           own local architecture-dependent modules in this directory with
6406           MakeMaker Makefile.PL or equivalent.  See "INSTALL" for details.
6407
6408       "sitearchexp"
6409           From sitearch.U:
6410
6411           This variable is the ~name expanded version of sitearch, so that
6412           you may use it directly in Makefiles or shell scripts.
6413
6414       "sitebin"
6415           From sitebin.U:
6416
6417           This variable holds the name of the directory in which the user
6418           wants to put add-on publicly executable files for the package in
6419           question.  It is most often a local directory such as
6420           /usr/local/bin. Programs using this variable must be prepared to
6421           deal with ~name substitution.  The standard distribution will put
6422           nothing in this directory.  After perl has been installed, users
6423           may install their own local executables in this directory with
6424           MakeMaker Makefile.PL or equivalent.  See "INSTALL" for details.
6425
6426       "sitebinexp"
6427           From sitebin.U:
6428
6429           This is the same as the sitebin variable, but is filename expanded
6430           at configuration time, for use in your makefiles.
6431
6432       "sitehtml1dir"
6433           From sitehtml1dir.U:
6434
6435           This variable contains the name of the directory in which site-
6436           specific html source pages are to be put.  It is the responsibility
6437           of the Makefile.SH to get the value of this into the proper
6438           command.  You must be prepared to do the ~name expansion yourself.
6439           The standard distribution will put nothing in this directory.
6440           After perl has been installed, users may install their own local
6441           html pages in this directory with MakeMaker Makefile.PL or
6442           equivalent.  See "INSTALL" for details.
6443
6444       "sitehtml1direxp"
6445           From sitehtml1dir.U:
6446
6447           This variable is the same as the sitehtml1dir variable, but is
6448           filename expanded at configuration time, for convenient use in
6449           makefiles.
6450
6451       "sitehtml3dir"
6452           From sitehtml3dir.U:
6453
6454           This variable contains the name of the directory in which site-
6455           specific library html source pages are to be put.  It is the
6456           responsibility of the Makefile.SH to get the value of this into the
6457           proper command.  You must be prepared to do the ~name expansion
6458           yourself.  The standard distribution will put nothing in this
6459           directory.  After perl has been installed, users may install their
6460           own local library html pages in this directory with MakeMaker
6461           Makefile.PL or equivalent.  See "INSTALL" for details.
6462
6463       "sitehtml3direxp"
6464           From sitehtml3dir.U:
6465
6466           This variable is the same as the sitehtml3dir variable, but is
6467           filename expanded at configuration time, for convenient use in
6468           makefiles.
6469
6470       "sitelib"
6471           From sitelib.U:
6472
6473           This variable contains the eventual value of the "SITELIB" symbol,
6474           which is the name of the private library for this package.  It may
6475           have a ~ on the front. It is up to the makefile to eventually
6476           create this directory while performing installation (with ~
6477           substitution).  The standard distribution will put nothing in this
6478           directory.  After perl has been installed, users may install their
6479           own local architecture-independent modules in this directory with
6480           MakeMaker Makefile.PL or equivalent.  See "INSTALL" for details.
6481
6482       "sitelib_stem"
6483           From sitelib.U:
6484
6485           This variable is $sitelibexp with any trailing version-specific
6486           component removed.  The elements in inc_version_list
6487           (inc_version_list.U) can be tacked onto this variable to generate a
6488           list of directories to search.
6489
6490       "sitelibexp"
6491           From sitelib.U:
6492
6493           This variable is the ~name expanded version of sitelib, so that you
6494           may use it directly in Makefiles or shell scripts.
6495
6496       "siteman1dir"
6497           From siteman1dir.U:
6498
6499           This variable contains the name of the directory in which site-
6500           specific manual source pages are to be put.  It is the
6501           responsibility of the Makefile.SH to get the value of this into the
6502           proper command.  You must be prepared to do the ~name expansion
6503           yourself.  The standard distribution will put nothing in this
6504           directory.  After perl has been installed, users may install their
6505           own local man1 pages in this directory with MakeMaker Makefile.PL
6506           or equivalent.  See "INSTALL" for details.
6507
6508       "siteman1direxp"
6509           From siteman1dir.U:
6510
6511           This variable is the same as the siteman1dir variable, but is
6512           filename expanded at configuration time, for convenient use in
6513           makefiles.
6514
6515       "siteman3dir"
6516           From siteman3dir.U:
6517
6518           This variable contains the name of the directory in which site-
6519           specific library man source pages are to be put.  It is the
6520           responsibility of the Makefile.SH to get the value of this into the
6521           proper command.  You must be prepared to do the ~name expansion
6522           yourself.  The standard distribution will put nothing in this
6523           directory.  After perl has been installed, users may install their
6524           own local man3 pages in this directory with MakeMaker Makefile.PL
6525           or equivalent.  See "INSTALL" for details.
6526
6527       "siteman3direxp"
6528           From siteman3dir.U:
6529
6530           This variable is the same as the siteman3dir variable, but is
6531           filename expanded at configuration time, for convenient use in
6532           makefiles.
6533
6534       "siteprefix"
6535           From siteprefix.U:
6536
6537           This variable holds the full absolute path of the directory below
6538           which the user will install add-on packages.  See "INSTALL" for
6539           usage and examples.
6540
6541       "siteprefixexp"
6542           From siteprefix.U:
6543
6544           This variable holds the full absolute path of the directory below
6545           which the user will install add-on packages.  Derived from
6546           siteprefix.
6547
6548       "sitescript"
6549           From sitescript.U:
6550
6551           This variable holds the name of the directory in which the user
6552           wants to put add-on publicly executable files for the package in
6553           question.  It is most often a local directory such as
6554           /usr/local/bin. Programs using this variable must be prepared to
6555           deal with ~name substitution.  The standard distribution will put
6556           nothing in this directory.  After perl has been installed, users
6557           may install their own local scripts in this directory with
6558           MakeMaker Makefile.PL or equivalent.  See "INSTALL" for details.
6559
6560       "sitescriptexp"
6561           From sitescript.U:
6562
6563           This is the same as the sitescript variable, but is filename
6564           expanded at configuration time, for use in your makefiles.
6565
6566       "sizesize"
6567           From sizesize.U:
6568
6569           This variable contains the size of a sizetype in bytes.
6570
6571       "sizetype"
6572           From sizetype.U:
6573
6574           This variable defines sizetype to be something like size_t,
6575           unsigned long, or whatever type is used to declare length
6576           parameters for string functions.
6577
6578       "sleep"
6579           From Loc.U:
6580
6581           This variable is defined but not used by Configure.  The value is
6582           the empty string and is not useful.
6583
6584       "sLOCALTIME_max"
6585           From time_size.U:
6586
6587           This variable defines the maximum value of the time_t offset that
6588           the system function localtime () accepts
6589
6590       "sLOCALTIME_min"
6591           From time_size.U:
6592
6593           This variable defines the minimum value of the time_t offset that
6594           the system function localtime () accepts
6595
6596       "smail"
6597           From Loc.U:
6598
6599           This variable is defined but not used by Configure.  The value is
6600           the empty string and is not useful.
6601
6602       "so"
6603           From so.U:
6604
6605           This variable holds the extension used to identify shared libraries
6606           (also known as shared objects) on the system. Usually set to "so".
6607
6608       "sockethdr"
6609           From d_socket.U:
6610
6611           This variable has any cpp "-I" flags needed for socket support.
6612
6613       "socketlib"
6614           From d_socket.U:
6615
6616           This variable has the names of any libraries needed for socket
6617           support.
6618
6619       "socksizetype"
6620           From socksizetype.U:
6621
6622           This variable holds the type used for the size argument for various
6623           socket calls like accept.  Usual values include socklen_t, size_t,
6624           and int.
6625
6626       "sort"
6627           From Loc.U:
6628
6629           This variable is used internally by Configure to determine the full
6630           pathname (if any) of the sort program.  After Configure runs, the
6631           value is reset to a plain "sort" and is not useful.
6632
6633       "spackage"
6634           From package.U:
6635
6636           This variable contains the name of the package being constructed,
6637           with the first letter uppercased, i.e. suitable for starting
6638           sentences.
6639
6640       "spitshell"
6641           From spitshell.U:
6642
6643           This variable contains the command necessary to spit out a runnable
6644           shell on this system.  It is either cat or a grep "-v" for #
6645           comments.
6646
6647       "sPRId64"
6648           From quadfio.U:
6649
6650           This variable, if defined, contains the string used by stdio to
6651           format 64-bit decimal numbers (format "d") for output.
6652
6653       "sPRIeldbl"
6654           From longdblfio.U:
6655
6656           This variable, if defined, contains the string used by stdio to
6657           format long doubles (format "e") for output.
6658
6659       "sPRIEUldbl"
6660           From longdblfio.U:
6661
6662           This variable, if defined, contains the string used by stdio to
6663           format long doubles (format "E") for output.  The "U" in the name
6664           is to separate this from sPRIeldbl so that even case-blind systems
6665           can see the difference.
6666
6667       "sPRIfldbl"
6668           From longdblfio.U:
6669
6670           This variable, if defined, contains the string used by stdio to
6671           format long doubles (format "f") for output.
6672
6673       "sPRIFUldbl"
6674           From longdblfio.U:
6675
6676           This variable, if defined, contains the string used by stdio to
6677           format long doubles (format "F") for output.  The "U" in the name
6678           is to separate this from sPRIfldbl so that even case-blind systems
6679           can see the difference.
6680
6681       "sPRIgldbl"
6682           From longdblfio.U:
6683
6684           This variable, if defined, contains the string used by stdio to
6685           format long doubles (format "g") for output.
6686
6687       "sPRIGUldbl"
6688           From longdblfio.U:
6689
6690           This variable, if defined, contains the string used by stdio to
6691           format long doubles (format "G") for output.  The "U" in the name
6692           is to separate this from sPRIgldbl so that even case-blind systems
6693           can see the difference.
6694
6695       "sPRIi64"
6696           From quadfio.U:
6697
6698           This variable, if defined, contains the string used by stdio to
6699           format 64-bit decimal numbers (format "i") for output.
6700
6701       "sPRIo64"
6702           From quadfio.U:
6703
6704           This variable, if defined, contains the string used by stdio to
6705           format 64-bit octal numbers (format "o") for output.
6706
6707       "sPRIu64"
6708           From quadfio.U:
6709
6710           This variable, if defined, contains the string used by stdio to
6711           format 64-bit unsigned decimal numbers (format "u") for output.
6712
6713       "sPRIx64"
6714           From quadfio.U:
6715
6716           This variable, if defined, contains the string used by stdio to
6717           format 64-bit hexadecimal numbers (format "x") for output.
6718
6719       "sPRIXU64"
6720           From quadfio.U:
6721
6722           This variable, if defined, contains the string used by stdio to
6723           format 64-bit hExADECimAl numbers (format "X") for output.  The "U"
6724           in the name is to separate this from sPRIx64 so that even case-
6725           blind systems can see the difference.
6726
6727       "srand48_r_proto"
6728           From d_srand48_r.U:
6729
6730           This variable encodes the prototype of srand48_r.  It is zero if
6731           d_srand48_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
6732           of reentr.h if d_srand48_r is defined.
6733
6734       "srandom_r_proto"
6735           From d_srandom_r.U:
6736
6737           This variable encodes the prototype of srandom_r.  It is zero if
6738           d_srandom_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
6739           of reentr.h if d_srandom_r is defined.
6740
6741       "src"
6742           From src.U:
6743
6744           This variable holds the (possibly relative) path of the package
6745           source.  It is up to the Makefile to use this variable and set
6746           "VPATH" accordingly to find the sources remotely.  Use $pkgsrc to
6747           have an absolute path.
6748
6749       "sSCNfldbl"
6750           From longdblfio.U:
6751
6752           This variable, if defined, contains the string used by stdio to
6753           format long doubles (format "f") for input.
6754
6755       "ssizetype"
6756           From ssizetype.U:
6757
6758           This variable defines ssizetype to be something like ssize_t, long
6759           or int.  It is used by functions that return a count of bytes or an
6760           error condition.  It must be a signed type.  We will pick a type
6761           such that sizeof(SSize_t) == sizeof(Size_t).
6762
6763       "startperl"
6764           From startperl.U:
6765
6766           This variable contains the string to put on the front of a perl
6767           script to make sure (hopefully) that it runs with perl and not some
6768           shell. Of course, that leading line must be followed by the
6769           classical perl idiom: eval 'exec perl -S $0 ${1+$@}' if
6770           $running_under_some_shell; to guarantee perl startup should the
6771           shell execute the script. Note that this magic incatation is not
6772           understood by csh.
6773
6774       "startsh"
6775           From startsh.U:
6776
6777           This variable contains the string to put on the front of a shell
6778           script to make sure (hopefully) that it runs with sh and not some
6779           other shell.
6780
6781       "static_ext"
6782           From Extensions.U:
6783
6784           This variable holds a list of "XS" extension files we want to link
6785           statically into the package.  It is used by Makefile.
6786
6787       "stdchar"
6788           From stdchar.U:
6789
6790           This variable conditionally defines "STDCHAR" to be the type of
6791           char used in stdio.h.  It has the values "unsigned char" or "char".
6792
6793       "stdio_base"
6794           From d_stdstdio.U:
6795
6796           This variable defines how, given a "FILE" pointer, fp, to access
6797           the _base field (or equivalent) of stdio.h's "FILE" structure.
6798           This will be used to define the macro FILE_base(fp).
6799
6800       "stdio_bufsiz"
6801           From d_stdstdio.U:
6802
6803           This variable defines how, given a "FILE" pointer, fp, to determine
6804           the number of bytes store in the I/O buffer pointer to by the _base
6805           field (or equivalent) of stdio.h's "FILE" structure.  This will be
6806           used to define the macro FILE_bufsiz(fp).
6807
6808       "stdio_cnt"
6809           From d_stdstdio.U:
6810
6811           This variable defines how, given a "FILE" pointer, fp, to access
6812           the _cnt field (or equivalent) of stdio.h's "FILE" structure.  This
6813           will be used to define the macro FILE_cnt(fp).
6814
6815       "stdio_filbuf"
6816           From d_stdstdio.U:
6817
6818           This variable defines how, given a "FILE" pointer, fp, to tell
6819           stdio to refill its internal buffers (?).  This will be used to
6820           define the macro FILE_filbuf(fp).
6821
6822       "stdio_ptr"
6823           From d_stdstdio.U:
6824
6825           This variable defines how, given a "FILE" pointer, fp, to access
6826           the _ptr field (or equivalent) of stdio.h's "FILE" structure.  This
6827           will be used to define the macro FILE_ptr(fp).
6828
6829       "stdio_stream_array"
6830           From stdio_streams.U:
6831
6832           This variable tells the name of the array holding the stdio
6833           streams.  Usual values include _iob, __iob, and __sF.
6834
6835       "strerror_r_proto"
6836           From d_strerror_r.U:
6837
6838           This variable encodes the prototype of strerror_r.  It is zero if
6839           d_strerror_r is undef, and one of the "REENTRANT_PROTO_T_ABC"
6840           macros of reentr.h if d_strerror_r is defined.
6841
6842       "strings"
6843           From i_string.U:
6844
6845           This variable holds the full path of the string header that will be
6846           used. Typically /usr/include/string.h or /usr/include/strings.h.
6847
6848       "submit"
6849           From Loc.U:
6850
6851           This variable is defined but not used by Configure.  The value is
6852           the empty string and is not useful.
6853
6854       "subversion"
6855           From patchlevel.U:
6856
6857           The subversion level of this package.  The value of subversion
6858           comes from the patchlevel.h file.  In a version number such as
6859           5.6.1, this is the 1.  In patchlevel.h, this is referred to as
6860           "PERL_SUBVERSION".  This is unique to perl.
6861
6862       "sysman"
6863           From sysman.U:
6864
6865           This variable holds the place where the manual is located on this
6866           system. It is not the place where the user wants to put his manual
6867           pages. Rather it is the place where Configure may look to find
6868           manual for unix commands (section 1 of the manual usually). See
6869           mansrc.
6870
6871   t
6872       "tail"
6873           From Loc.U:
6874
6875           This variable is defined but not used by Configure.  The value is
6876           the empty string and is not useful.
6877
6878       "tar"
6879           From Loc.U:
6880
6881           This variable is defined but not used by Configure.  The value is
6882           the empty string and is not useful.
6883
6884       "targetarch"
6885           From Cross.U:
6886
6887           If cross-compiling, this variable contains the target architecture.
6888           If not, this will be empty.
6889
6890       "tbl"
6891           From Loc.U:
6892
6893           This variable is defined but not used by Configure.  The value is
6894           the empty string and is not useful.
6895
6896       "tee"
6897           From Loc.U:
6898
6899           This variable is defined but not used by Configure.  The value is
6900           the empty string and is not useful.
6901
6902       "test"
6903           From Loc.U:
6904
6905           This variable is used internally by Configure to determine the full
6906           pathname (if any) of the test program.  After Configure runs, the
6907           value is reset to a plain "test" and is not useful.
6908
6909       "timeincl"
6910           From i_time.U:
6911
6912           This variable holds the full path of the included time header(s).
6913
6914       "timetype"
6915           From d_time.U:
6916
6917           This variable holds the type returned by time(). It can be long, or
6918           time_t on "BSD" sites (in which case <sys/types.h> should be
6919           included). Anyway, the type Time_t should be used.
6920
6921       "tmpnam_r_proto"
6922           From d_tmpnam_r.U:
6923
6924           This variable encodes the prototype of tmpnam_r.  It is zero if
6925           d_tmpnam_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
6926           of reentr.h if d_tmpnam_r is defined.
6927
6928       "to"
6929           From Cross.U:
6930
6931           This variable contains the command used by Configure to copy to
6932           from the target host.  Useful and available only during Perl build.
6933           The string ":" if not cross-compiling.
6934
6935       "touch"
6936           From Loc.U:
6937
6938           This variable is used internally by Configure to determine the full
6939           pathname (if any) of the touch program.  After Configure runs, the
6940           value is reset to a plain "touch" and is not useful.
6941
6942       "tr"
6943           From Loc.U:
6944
6945           This variable is used internally by Configure to determine the full
6946           pathname (if any) of the tr program.  After Configure runs, the
6947           value is reset to a plain "tr" and is not useful.
6948
6949       "trnl"
6950           From trnl.U:
6951
6952           This variable contains the value to be passed to the tr(1) command
6953           to transliterate a newline.  Typical values are "\012" and "\n".
6954           This is needed for "EBCDIC" systems where newline is not
6955           necessarily "\012".
6956
6957       "troff"
6958           From Loc.U:
6959
6960           This variable is defined but not used by Configure.  The value is
6961           the empty string and is not useful.
6962
6963       "ttyname_r_proto"
6964           From d_ttyname_r.U:
6965
6966           This variable encodes the prototype of ttyname_r.  It is zero if
6967           d_ttyname_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros
6968           of reentr.h if d_ttyname_r is defined.
6969
6970   u
6971       "u16size"
6972           From perlxv.U:
6973
6974           This variable is the size of an U16 in bytes.
6975
6976       "u16type"
6977           From perlxv.U:
6978
6979           This variable contains the C type used for Perl's U16.
6980
6981       "u32size"
6982           From perlxv.U:
6983
6984           This variable is the size of an U32 in bytes.
6985
6986       "u32type"
6987           From perlxv.U:
6988
6989           This variable contains the C type used for Perl's U32.
6990
6991       "u64size"
6992           From perlxv.U:
6993
6994           This variable is the size of an U64 in bytes.
6995
6996       "u64type"
6997           From perlxv.U:
6998
6999           This variable contains the C type used for Perl's U64.
7000
7001       "u8size"
7002           From perlxv.U:
7003
7004           This variable is the size of an U8 in bytes.
7005
7006       "u8type"
7007           From perlxv.U:
7008
7009           This variable contains the C type used for Perl's U8.
7010
7011       "uidformat"
7012           From uidf.U:
7013
7014           This variable contains the format string used for printing a Uid_t.
7015
7016       "uidsign"
7017           From uidsign.U:
7018
7019           This variable contains the signedness of a uidtype.  1 for
7020           unsigned, -1 for signed.
7021
7022       "uidsize"
7023           From uidsize.U:
7024
7025           This variable contains the size of a uidtype in bytes.
7026
7027       "uidtype"
7028           From uidtype.U:
7029
7030           This variable defines Uid_t to be something like uid_t, int,
7031           ushort, or whatever type is used to declare user ids in the kernel.
7032
7033       "uname"
7034           From Loc.U:
7035
7036           This variable is used internally by Configure to determine the full
7037           pathname (if any) of the uname program.  After Configure runs, the
7038           value is reset to a plain "uname" and is not useful.
7039
7040       "uniq"
7041           From Loc.U:
7042
7043           This variable is used internally by Configure to determine the full
7044           pathname (if any) of the uniq program.  After Configure runs, the
7045           value is reset to a plain "uniq" and is not useful.
7046
7047       "uquadtype"
7048           From quadtype.U:
7049
7050           This variable defines Uquad_t to be something like unsigned long,
7051           unsigned int, unsigned long long, uint64_t, or whatever type is
7052           used for 64-bit integers.
7053
7054       "use5005threads"
7055           From usethreads.U:
7056
7057           This variable conditionally defines the USE_5005THREADS symbol, and
7058           indicates that Perl should be built to use the 5.005-based
7059           threading implementation. Only valid up to 5.8.x.
7060
7061       "use64bitall"
7062           From use64bits.U:
7063
7064           This variable conditionally defines the USE_64_BIT_ALL symbol, and
7065           indicates that 64-bit integer types should be used when available.
7066           The maximal possible 64-bitness is employed: LP64 or ILP64, meaning
7067           that you will be able to use more than 2 gigabytes of memory.  This
7068           mode is even more binary incompatible than USE_64_BIT_INT. You may
7069           not be able to run the resulting executable in a 32-bit "CPU" at
7070           all or you may need at least to reboot your "OS" to 64-bit mode.
7071
7072       "use64bitint"
7073           From use64bits.U:
7074
7075           This variable conditionally defines the USE_64_BIT_INT symbol, and
7076           indicates that 64-bit integer types should be used when available.
7077           The minimal possible 64-bitness is employed, just enough to get
7078           64-bit integers into Perl.  This may mean using for example "long
7079           longs", while your memory may still be limited to 2 gigabytes.
7080
7081       "usecrosscompile"
7082           From Cross.U:
7083
7084           This variable conditionally defines the "USE_CROSS_COMPILE" symbol,
7085           and indicates that Perl has been cross-compiled.
7086
7087       "usedevel"
7088           From Devel.U:
7089
7090           This variable indicates that Perl was configured with development
7091           features enabled.  This should not be done for production builds.
7092
7093       "usedl"
7094           From dlsrc.U:
7095
7096           This variable indicates if the system supports dynamic loading of
7097           some sort.  See also dlsrc and dlobj.
7098
7099       "usedtrace"
7100           From usedtrace.U:
7101
7102           This variable indicates whether we are compiling with dtrace
7103           support. See also dtrace.
7104
7105       "usefaststdio"
7106           From usefaststdio.U:
7107
7108           This variable conditionally defines the "USE_FAST_STDIO" symbol,
7109           and indicates that Perl should be built to use "fast stdio".
7110           Defaults to define in Perls 5.8 and earlier, to undef later.
7111
7112       "useithreads"
7113           From usethreads.U:
7114
7115           This variable conditionally defines the "USE_ITHREADS" symbol, and
7116           indicates that Perl should be built to use the interpreter-based
7117           threading implementation.
7118
7119       "uselargefiles"
7120           From uselfs.U:
7121
7122           This variable conditionally defines the "USE_LARGE_FILES" symbol,
7123           and indicates that large file interfaces should be used when
7124           available.
7125
7126       "uselongdouble"
7127           From uselongdbl.U:
7128
7129           This variable conditionally defines the "USE_LONG_DOUBLE" symbol,
7130           and indicates that long doubles should be used when available.
7131
7132       "usemallocwrap"
7133           From mallocsrc.U:
7134
7135           This variable contains y if we are wrapping malloc to prevent
7136           integer overflow during size calculations.
7137
7138       "usemorebits"
7139           From usemorebits.U:
7140
7141           This variable conditionally defines the "USE_MORE_BITS" symbol, and
7142           indicates that explicit 64-bit interfaces and long doubles should
7143           be used when available.
7144
7145       "usemultiplicity"
7146           From usemultiplicity.U:
7147
7148           This variable conditionally defines the "MULTIPLICITY" symbol, and
7149           indicates that Perl should be built to use multiplicity.
7150
7151       "usemymalloc"
7152           From mallocsrc.U:
7153
7154           This variable contains y if the malloc that comes with this package
7155           is desired over the system's version of malloc.  People often
7156           include special versions of malloc for effiency, but such versions
7157           are often less portable.  See also mallocsrc and mallocobj.  If
7158           this is "y", then -lmalloc is removed from $libs.
7159
7160       "usenm"
7161           From usenm.U:
7162
7163           This variable contains "true" or "false" depending whether the nm
7164           extraction is wanted or not.
7165
7166       "useopcode"
7167           From Extensions.U:
7168
7169           This variable holds either "true" or "false" to indicate whether
7170           the Opcode extension should be used.  The sole use for this
7171           currently is to allow an easy mechanism for users to skip the
7172           Opcode extension from the Configure command line.
7173
7174       "useperlio"
7175           From useperlio.U:
7176
7177           This variable conditionally defines the "USE_PERLIO" symbol, and
7178           indicates that the PerlIO abstraction should be used throughout.
7179
7180       "useposix"
7181           From Extensions.U:
7182
7183           This variable holds either "true" or "false" to indicate whether
7184           the "POSIX" extension should be used.  The sole use for this
7185           currently is to allow an easy mechanism for hints files to indicate
7186           that "POSIX" will not compile on a particular system.
7187
7188       "usereentrant"
7189           From usethreads.U:
7190
7191           This variable conditionally defines the "USE_REENTRANT_API" symbol,
7192           which indicates that the thread code may try to use the various _r
7193           versions of library functions.  This is only potentially meaningful
7194           if usethreads is set and is very experimental, it is not even
7195           prompted for.
7196
7197       "userelocatableinc"
7198           From bin.U:
7199
7200           This variable is set to true to indicate that perl should relocate
7201           @"INC" entries at runtime based on the path to the perl binary.
7202           Any @"INC" paths starting .../ are relocated relative to the
7203           directory containing the perl binary, and a logical cleanup of the
7204           path is then made around the join point (removing dir/../ pairs)
7205
7206       "usesfio"
7207           From d_sfio.U:
7208
7209           This variable is set to true when the user agrees to use sfio.  It
7210           is set to false when sfio is not available or when the user
7211           explicitely requests not to use sfio.  It is here primarily so that
7212           command-line settings can override the auto-detection of d_sfio
7213           without running into a "WHOA THERE".
7214
7215       "useshrplib"
7216           From libperl.U:
7217
7218           This variable is set to "true" if the user wishes to build a shared
7219           libperl, and "false" otherwise.
7220
7221       "usesitecustomize"
7222           From d_sitecustomize.U:
7223
7224           This variable is set to true when the user requires a mechanism
7225           that allows the sysadmin to add entries to @"INC" at runtime.  This
7226           variable being set, makes perl run $sitelib/sitecustomize.pl at
7227           startup.
7228
7229       "usesocks"
7230           From usesocks.U:
7231
7232           This variable conditionally defines the "USE_SOCKS" symbol, and
7233           indicates that Perl should be built to use "SOCKS".
7234
7235       "usethreads"
7236           From usethreads.U:
7237
7238           This variable conditionally defines the "USE_THREADS" symbol, and
7239           indicates that Perl should be built to use threads.
7240
7241       "usevendorprefix"
7242           From vendorprefix.U:
7243
7244           This variable tells whether the vendorprefix and consequently other
7245           vendor* paths are in use.
7246
7247       "usevfork"
7248           From d_vfork.U:
7249
7250           This variable is set to true when the user accepts to use vfork.
7251           It is set to false when no vfork is available or when the user
7252           explicitely requests not to use vfork.
7253
7254       "usrinc"
7255           From usrinc.U:
7256
7257           This variable holds the path of the include files, which is usually
7258           /usr/include. It is mainly used by other Configure units.
7259
7260       "uuname"
7261           From Loc.U:
7262
7263           This variable is defined but not used by Configure.  The value is
7264           the empty string and is not useful.
7265
7266       "uvoformat"
7267           From perlxvf.U:
7268
7269           This variable contains the format string used for printing a Perl
7270           "UV" as an unsigned octal integer.
7271
7272       "uvsize"
7273           From perlxv.U:
7274
7275           This variable is the size of a "UV" in bytes.
7276
7277       "uvtype"
7278           From perlxv.U:
7279
7280           This variable contains the C type used for Perl's "UV".
7281
7282       "uvuformat"
7283           From perlxvf.U:
7284
7285           This variable contains the format string used for printing a Perl
7286           "UV" as an unsigned decimal integer.
7287
7288       "uvxformat"
7289           From perlxvf.U:
7290
7291           This variable contains the format string used for printing a Perl
7292           "UV" as an unsigned hexadecimal integer in lowercase abcdef.
7293
7294       "uvXUformat"
7295           From perlxvf.U:
7296
7297           This variable contains the format string used for printing a Perl
7298           "UV" as an unsigned hexadecimal integer in uppercase "ABCDEF".
7299
7300   v
7301       "vaproto"
7302           From vaproto.U:
7303
7304           This variable conditionally defines "CAN_VAPROTO" on systems
7305           supporting prototype declaration of functions with a variable
7306           number of arguments. See also prototype.
7307
7308       "vendorarch"
7309           From vendorarch.U:
7310
7311           This variable contains the value of the "PERL_VENDORARCH" symbol.
7312           It may have a ~ on the front.  The standard distribution will put
7313           nothing in this directory.  Vendors who distribute perl may wish to
7314           place their own architecture-dependent modules and extensions in
7315           this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or
7316           equivalent.  See "INSTALL" for details.
7317
7318       "vendorarchexp"
7319           From vendorarch.U:
7320
7321           This variable is the ~name expanded version of vendorarch, so that
7322           you may use it directly in Makefiles or shell scripts.
7323
7324       "vendorbin"
7325           From vendorbin.U:
7326
7327           This variable contains the eventual value of the "VENDORBIN"
7328           symbol.  It may have a ~ on the front.  The standard distribution
7329           will put nothing in this directory.  Vendors who distribute perl
7330           may wish to place additional binaries in this directory with
7331           MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent.  See
7332           "INSTALL" for details.
7333
7334       "vendorbinexp"
7335           From vendorbin.U:
7336
7337           This variable is the ~name expanded version of vendorbin, so that
7338           you may use it directly in Makefiles or shell scripts.
7339
7340       "vendorhtml1dir"
7341           From vendorhtml1dir.U:
7342
7343           This variable contains the name of the directory for html pages.
7344           It may have a ~ on the front.  The standard distribution will put
7345           nothing in this directory.  Vendors who distribute perl may wish to
7346           place their own html pages in this directory with MakeMaker
7347           Makefile.PL "INSTALLDIRS"=vendor or equivalent.  See "INSTALL" for
7348           details.
7349
7350       "vendorhtml1direxp"
7351           From vendorhtml1dir.U:
7352
7353           This variable is the ~name expanded version of vendorhtml1dir, so
7354           that you may use it directly in Makefiles or shell scripts.
7355
7356       "vendorhtml3dir"
7357           From vendorhtml3dir.U:
7358
7359           This variable contains the name of the directory for html library
7360           pages.  It may have a ~ on the front.  The standard distribution
7361           will put nothing in this directory.  Vendors who distribute perl
7362           may wish to place their own html pages for modules and extensions
7363           in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor
7364           or equivalent.  See "INSTALL" for details.
7365
7366       "vendorhtml3direxp"
7367           From vendorhtml3dir.U:
7368
7369           This variable is the ~name expanded version of vendorhtml3dir, so
7370           that you may use it directly in Makefiles or shell scripts.
7371
7372       "vendorlib"
7373           From vendorlib.U:
7374
7375           This variable contains the eventual value of the "VENDORLIB"
7376           symbol, which is the name of the private library for this package.
7377           The standard distribution will put nothing in this directory.
7378           Vendors who distribute perl may wish to place their own modules in
7379           this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or
7380           equivalent.  See "INSTALL" for details.
7381
7382       "vendorlib_stem"
7383           From vendorlib.U:
7384
7385           This variable is $vendorlibexp with any trailing version-specific
7386           component removed.  The elements in inc_version_list
7387           (inc_version_list.U) can be tacked onto this variable to generate a
7388           list of directories to search.
7389
7390       "vendorlibexp"
7391           From vendorlib.U:
7392
7393           This variable is the ~name expanded version of vendorlib, so that
7394           you may use it directly in Makefiles or shell scripts.
7395
7396       "vendorman1dir"
7397           From vendorman1dir.U:
7398
7399           This variable contains the name of the directory for man1 pages.
7400           It may have a ~ on the front.  The standard distribution will put
7401           nothing in this directory.  Vendors who distribute perl may wish to
7402           place their own man1 pages in this directory with MakeMaker
7403           Makefile.PL "INSTALLDIRS"=vendor or equivalent.  See "INSTALL" for
7404           details.
7405
7406       "vendorman1direxp"
7407           From vendorman1dir.U:
7408
7409           This variable is the ~name expanded version of vendorman1dir, so
7410           that you may use it directly in Makefiles or shell scripts.
7411
7412       "vendorman3dir"
7413           From vendorman3dir.U:
7414
7415           This variable contains the name of the directory for man3 pages.
7416           It may have a ~ on the front.  The standard distribution will put
7417           nothing in this directory.  Vendors who distribute perl may wish to
7418           place their own man3 pages in this directory with MakeMaker
7419           Makefile.PL "INSTALLDIRS"=vendor or equivalent.  See "INSTALL" for
7420           details.
7421
7422       "vendorman3direxp"
7423           From vendorman3dir.U:
7424
7425           This variable is the ~name expanded version of vendorman3dir, so
7426           that you may use it directly in Makefiles or shell scripts.
7427
7428       "vendorprefix"
7429           From vendorprefix.U:
7430
7431           This variable holds the full absolute path of the directory below
7432           which the vendor will install add-on packages.  See "INSTALL" for
7433           usage and examples.
7434
7435       "vendorprefixexp"
7436           From vendorprefix.U:
7437
7438           This variable holds the full absolute path of the directory below
7439           which the vendor will install add-on packages.  Derived from
7440           vendorprefix.
7441
7442       "vendorscript"
7443           From vendorscript.U:
7444
7445           This variable contains the eventual value of the "VENDORSCRIPT"
7446           symbol.  It may have a ~ on the front.  The standard distribution
7447           will put nothing in this directory.  Vendors who distribute perl
7448           may wish to place additional executable scripts in this directory
7449           with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent.  See
7450           "INSTALL" for details.
7451
7452       "vendorscriptexp"
7453           From vendorscript.U:
7454
7455           This variable is the ~name expanded version of vendorscript, so
7456           that you may use it directly in Makefiles or shell scripts.
7457
7458       "version"
7459           From patchlevel.U:
7460
7461           The full version number of this package, such as 5.6.1 (or 5_6_1).
7462           This combines revision, patchlevel, and subversion to get the full
7463           version number, including any possible subversions.  This is
7464           suitable for use as a directory name, and hence is filesystem
7465           dependent.
7466
7467       "version_patchlevel_string"
7468           From patchlevel.U:
7469
7470           This is a string combining version, subversion and perl_patchlevel
7471           (if perl_patchlevel is non-zero).  It is typically something like
7472           'version 7 subversion 1'  or 'version 7 subversion 1 patchlevel
7473           11224' It is computed here to avoid duplication of code in
7474           myconfig.SH and lib/Config.pm.
7475
7476       "versiononly"
7477           From versiononly.U:
7478
7479           If set, this symbol indicates that only the version-specific
7480           components of a perl installation should be installed.  This may be
7481           useful for making a test installation of a new version without
7482           disturbing the existing installation.  Setting versiononly is
7483           equivalent to setting installperl's -v option.  In particular, the
7484           non-versioned scripts and programs such as a2p, c2ph, h2xs, pod2*,
7485           and perldoc are not installed (see "INSTALL" for a more complete
7486           list).  Nor are the man pages installed.  Usually, this is undef.
7487
7488       "vi"
7489           From Loc.U:
7490
7491           This variable is defined but not used by Configure.  The value is
7492           the empty string and is not useful.
7493
7494       "voidflags"
7495           From voidflags.U:
7496
7497           This variable contains the eventual value of the "VOIDFLAGS"
7498           symbol, which indicates how much support of the void type is given
7499           by this compiler.  See "VOIDFLAGS" for more info.
7500
7501   x
7502       "xlibpth"
7503           From libpth.U:
7504
7505           This variable holds extra path (space-separated) used to find
7506           libraries on this platform, for example "CPU"-specific libraries
7507           (on multi-"CPU" platforms) may be listed here.
7508
7509   y
7510       "yacc"
7511           From yacc.U:
7512
7513           This variable holds the name of the compiler compiler we want to
7514           use in the Makefile. It can be yacc, byacc, or bison -y.
7515
7516       "yaccflags"
7517           From yacc.U:
7518
7519           This variable contains any additional yacc flags desired by the
7520           user.  It is up to the Makefile to use this.
7521
7522   z
7523       "zcat"
7524           From Loc.U:
7525
7526           This variable is defined but not used by Configure.  The value is
7527           the empty string and is not useful.
7528
7529       "zip"
7530           From Loc.U:
7531
7532           This variable is used internally by Configure to determine the full
7533           pathname (if any) of the zip program.  After Configure runs, the
7534           value is reset to a plain "zip" and is not useful.
7535

GIT DATA

7537       Information on the git commit from which the current perl binary was
7538       compiled can be found in the variable $Config::Git_Data.  The variable
7539       is a structured string that looks something like this:
7540
7541         git_commit_id='ea0c2dbd5f5ac6845ecc7ec6696415bf8e27bd52'
7542         git_describe='GitLive-blead-1076-gea0c2db'
7543         git_branch='smartmatch'
7544         git_uncommitted_changes=''
7545         git_commit_id_title='Commit id:'
7546         git_commit_date='2009-05-09 17:47:31 +0200'
7547
7548       Its format is not guaranteed not to change over time.
7549

NOTE

7551       This module contains a good example of how to use tie to implement a
7552       cache and an example of how to make a tied variable readonly to those
7553       outside of it.
7554
7555
7556
7557perl v5.12.4                      2011-11-04                       Config(3pm)
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