1PERL571DELTA(1) Perl Programmers Reference Guide PERL571DELTA(1)
2
6 perl571delta - what's new for perl v5.7.1
7
9 This document describes differences between the 5.7.0 release and the
10 5.7.1 release.
11 (To view the differences between the 5.6.0 release and the 5.7.0
13 release, see perl570delta.)
14
16 (This change was already made in 5.7.0 but bears repeating here.)
17 A potential security vulnerability in the optional suidperl component
19 of Perl was identified in August 2000. suidperl is neither built nor
20 installed by default. As of April 2001 the only known vulnerable
21 platform is Linux, most likely all Linux distributions. CERT and
22 various vendors and distributors have been alerted about the
23 vulnerability. See
24 http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt for
25 more information.
26 The problem was caused by Perl trying to report a suspected security
28 exploit attempt using an external program, /bin/mail. On Linux
29 platforms the /bin/mail program had an undocumented feature which when
30 combined with suidperl gave access to a root shell, resulting in a
31 serious compromise instead of reporting the exploit attempt. If you
32 don't have /bin/mail, or if you have 'safe setuid scripts', or if
33 suidperl is not installed, you are safe.
34 The exploit attempt reporting feature has been completely removed from
36 all the Perl 5.7 releases (and will be gone also from the maintenance
37 release 5.6.1), so that particular vulnerability isn't there anymore.
38 However, further security vulnerabilities are, unfortunately, always
39 possible. The suidperl code is being reviewed and if deemed too risky
40 to continue to be supported, it may be completely removed from future
41 releases. In any case, suidperl should only be used by security
42 experts who know exactly what they are doing and why they are using
43 suidperl instead of some other solution such as sudo ( see
44 http://www.courtesan.com/sudo/ ).
45
47 · Although "you shouldn't do that", it was possible to write code
48 that depends on Perl's hashed key order (Data::Dumper does this).
49 The new algorithm "One-at-a-Time" produces a different hashed key
50 order. More details are in "Performance Enhancements".
51 · The list of filenames from glob() (or <...>) is now by default
53 sorted alphabetically to be csh-compliant. (bsd_glob() does still
54 sort platform natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is
55 specified.)
56
58 AUTOLOAD Is Now Lvaluable
59 AUTOLOAD is now lvaluable, meaning that you can add the :lvalue
60 attribute to AUTOLOAD subroutines and you can assign to the AUTOLOAD
61 return value.
62 PerlIO is Now The Default
64 · IO is now by default done via PerlIO rather than system's "stdio".
65 PerlIO allows "layers" to be "pushed" onto a file handle to alter
66 the handle's behaviour. Layers can be specified at open time via
67 3-arg form of open:
68 open($fh,'>:crlf :utf8', $path) || ...
70 or on already opened handles via extended "binmode":
72 binmode($fh,':encoding(iso-8859-7)');
74 The built-in layers are: unix (low level read/write), stdio (as in
76 previous Perls), perlio (re-implementation of stdio buffering in a
77 portable manner), crlf (does CRLF <=> "\n" translation as on Win32,
78 but available on any platform). A mmap layer may be available if
79 platform supports it (mostly Unixes).
80 Layers to be applied by default may be specified via the 'open'
82 pragma.
83 See "Installation and Configuration Improvements" for the effects
85 of PerlIO on your architecture name.
86 · File handles can be marked as accepting Perl's internal encoding of
88 Unicode (UTF-8 or UTF-EBCDIC depending on platform) by a pseudo
89 layer ":utf8" :
90 open($fh,">:utf8","Uni.txt");
92 Note for EBCDIC users: the pseudo layer ":utf8" is erroneously
94 named for you since it's not UTF-8 what you will be getting but
95 instead UTF-EBCDIC. See perlunicode, utf8, and
96 http://www.unicode.org/unicode/reports/tr16/ for more information.
97 In future releases this naming may change.
98 · File handles can translate character encodings from/to Perl's
100 internal Unicode form on read/write via the ":encoding()" layer.
101 · File handles can be opened to "in memory" files held in Perl
103 scalars via:
104 open($fh,'>', \$variable) || ...
106 · Anonymous temporary files are available without need to 'use
108 FileHandle' or other module via
109 open($fh,"+>", undef) || ...
111 That is a literal undef, not an undefined value.
113 · The list form of "open" is now implemented for pipes (at least on
115 Unix):
116 open($fh,"-|", 'cat', '/etc/motd')
118 creates a pipe, and runs the equivalent of exec('cat', '/etc/motd')
120 in the child process.
121 · The following builtin functions are now overridable: chop(),
123 chomp(), each(), keys(), pop(), push(), shift(), splice(),
124 unshift().
125 · Formats now support zero-padded decimal fields.
127 · Perl now tries internally to use integer values in numeric
129 conversions and basic arithmetics (+ - * /) if the arguments are
130 integers, and tries also to keep the results stored internally as
131 integers. This change leads into often slightly faster and always
132 less lossy arithmetics. (Previously Perl always preferred floating
133 point numbers in its math.)
134 · The printf() and sprintf() now support parameter reordering using
136 the "%\d+\$" and "*\d+\$" syntaxes. For example
137 print "%2\$s %1\$s\n", "foo", "bar";
139 will print "bar foo\n"; This feature helps in writing
141 internationalised software.
142 · Unicode in general should be now much more usable. Unicode can be
144 used in hash keys, Unicode in regular expressions should work now,
145 Unicode in tr/// should work now (though tr/// seems to be a
146 particularly tricky to get right, so you have been warned)
147 · The Unicode Character Database coming with Perl has been upgraded
149 to Unicode 3.1. For more information, see http://www.unicode.org/
150 , and http://www.unicode.org/unicode/reports/tr27/
151 For developers interested in enhancing Perl's Unicode capabilities:
153 almost all the UCD files are included with the Perl distribution in
154 the lib/unicode subdirectory. The most notable omission, for space
155 considerations, is the Unihan database.
156 · The Unicode character classes \p{Blank} and \p{SpacePerl} have been
158 added. "Blank" is like C isblank(), that is, it contains only
159 "horizontal whitespace" (the space character is, the newline
160 isn't), and the "SpacePerl" is the Unicode equivalent of "\s"
161 (\p{Space} isn't, since that includes the vertical tabulator
162 character, whereas "\s" doesn't.)
163 Signals Are Now Safe
165 Perl used to be fragile in that signals arriving at inopportune moments
166 could corrupt Perl's internal state.
167
169 New Modules
170 · B::Concise, by Stephen McCamant, is a new compiler backend for
171 walking the Perl syntax tree, printing concise info about ops. The
172 output is highly customisable.
173 See B::Concise for more information.
175 · Class::ISA, by Sean Burke, for reporting the search path for a
177 class's ISA tree, has been added.
178 See Class::ISA for more information.
180 · Cwd has now a split personality: if possible, an extension is used,
182 (this will hopefully be both faster and more secure and robust) but
183 if not possible, the familiar Perl library implementation is used.
184 · Digest, a frontend module for calculating digests (checksums), from
186 Gisle Aas, has been added.
187 See Digest for more information.
189 · Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
191 has been added.
192 use Digest::MD5 'md5_hex';
194 $digest = md5_hex("Thirsty Camel");
196 print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
198 NOTE: the MD5 backward compatibility module is deliberately not
200 included since its use is discouraged.
201 See Digest::MD5 for more information.
203 · Encode, by Nick Ing-Simmons, provides a mechanism to translate
205 between different character encodings. Support for Unicode,
206 ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
207 compiled in to the module. Several other encodings (like Japanese,
208 Chinese, and MacIntosh encodings) are included and will be loaded
209 at runtime.
210 Any encoding supported by Encode module is also available to the
212 ":encoding()" layer if PerlIO is used.
213 See Encode for more information.
215 · Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
217 from Damian Conway.
218 # in MyFilter.pm:
220 package MyFilter;
222 use Filter::Simple sub {
224 while (my ($from, $to) = splice @_, 0, 2) {
225 s/$from/$to/g;
226 }
227 };
228 1;
230 # in user's code:
232 use MyFilter qr/red/ => 'green';
234 print "red\n"; # this code is filtered, will print "green\n"
236 print "bored\n"; # this code is filtered, will print "bogreen\n"
237 no MyFilter;
239 print "red\n"; # this code is not filtered, will print "red\n"
241 See Filter::Simple for more information.
243 · Filter::Util::Call, by Paul Marquess, provides you with the
245 framework to write Source Filters in Perl. For most uses the
246 frontend Filter::Simple is to be preferred. See Filter::Util::Call
247 for more information.
248 · Locale::Constants, Locale::Country, Locale::Currency, and
250 Locale::Language, from Neil Bowers, have been added. They provide
251 the codes for various locale standards, such as "fr" for France,
252 "usd" for US Dollar, and "jp" for Japanese.
253 use Locale::Country;
255 $country = code2country('jp'); # $country gets 'Japan'
257 $code = country2code('Norway'); # $code gets 'no'
258 See Locale::Constants, Locale::Country, Locale::Currency, and
260 Locale::Language for more information.
261 · MIME::Base64, by Gisle Aas, allows you to encode data in base64.
263 use MIME::Base64;
265 $encoded = encode_base64('Aladdin:open sesame');
267 $decoded = decode_base64($encoded);
268 print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
270 See MIME::Base64 for more information.
272 · MIME::QuotedPrint, by Gisle Aas, allows you to encode data in
274 quoted-printable encoding.
275 use MIME::QuotedPrint;
277 $encoded = encode_qp("Smiley in Unicode: \x{263a}");
279 $decoded = decode_qp($encoded);
280 print $encoded, "\n"; # "Smiley in Unicode: =263A"
282 MIME::QuotedPrint has been enhanced to provide the basic methods
284 necessary to use it with PerlIO::Via as in :
285 use MIME::QuotedPrint;
287 open($fh,">Via(MIME::QuotedPrint)",$path)
288 See MIME::QuotedPrint for more information.
290 · PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
292 IO to "in memory" Perl scalars as discussed above. It also serves
293 as an example of a loadable layer. Other future possibilities
294 include PerlIO::Array and PerlIO::Code. See PerlIO::Scalar for
295 more information.
296 · PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
298 PerlIO layer functionality provided by a class (typically
299 implemented in perl code).
300 use MIME::QuotedPrint;
302 open($fh,">Via(MIME::QuotedPrint)",$path)
303 This will automatically convert everything output to $fh to Quoted-
305 Printable. See PerlIO::Via for more information.
306 · Pod::Text::Overstrike, by Joe Smith, has been added. It converts
308 POD data to formatted overstrike text. See Pod::Text::Overstrike
309 for more information.
310 · Switch from Damian Conway has been added. Just by saying
312 use Switch;
314 you have "switch" and "case" available in Perl.
316 use Switch;
318 switch ($val) {
320 case 1 { print "number 1" }
322 case "a" { print "string a" }
323 case [1..10,42] { print "number in list" }
324 case (@array) { print "number in list" }
325 case /\w+/ { print "pattern" }
326 case qr/\w+/ { print "pattern" }
327 case (%hash) { print "entry in hash" }
328 case (\%hash) { print "entry in hash" }
329 case (\&sub) { print "arg to subroutine" }
330 else { print "previous case not true" }
331 }
332 See Switch for more information.
334 · Text::Balanced from Damian Conway has been added, for extracting
336 delimited text sequences from strings.
337 use Text::Balanced 'extract_delimited';
339 ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
341 $a will be "'never say never'", $b will be ', he never said'.
343 In addition to extract_delimited() there are also
345 extract_bracketed(), extract_quotelike(), extract_codeblock(),
346 extract_variable(), extract_tagged(), extract_multiple(),
347 gen_delimited_pat(), and gen_extract_tagged(). With these you can
348 implement rather advanced parsing algorithms. See Text::Balanced
349 for more information.
350 · Tie::RefHash::Nestable, by Edward Avis, allows storing hash
352 references (unlike the standard Tie::RefHash) The module is
353 contained within Tie::RefHash.
354 · XS::Typemap, by Tim Jenness, is a test extension that exercises XS
356 typemaps. Nothing gets installed but for extension writers the
357 code is worth studying.
358 Updated And Improved Modules and Pragmata
360 · B::Deparse should be now more robust. It still far from providing
361 a full round trip for any random piece of Perl code, though, and is
362 under active development: expect more robustness in 5.7.2.
363 · Class::Struct can now define the classes in compile time.
365 · Math::BigFloat has undergone much fixing, and in addition the
367 fmod() function now supports modulus operations.
368 ( The fixed Math::BigFloat module is also available in CPAN for
370 those who can't upgrade their Perl:
371 http://www.cpan.org/authors/id/J/JP/JPEACOCK/ )
372 · Devel::Peek now has an interface for the Perl memory statistics
374 (this works only if you are using perl's malloc, and if you have
375 compiled with debugging).
376 · IO::Socket has now atmark() method, which returns true if the
378 socket is positioned at the out-of-band mark. The method is also
379 exportable as a sockatmark() function.
380 · IO::Socket::INET has support for ReusePort option (if your platform
382 supports it). The Reuse option now has an alias, ReuseAddr. For
383 clarity you may want to prefer ReuseAddr.
384 · Net::Ping has been enhanced. There is now "external" protocol
386 which uses Net::Ping::External module which runs external ping(1)
387 and parses the output. An alpha version of Net::Ping::External is
388 available in CPAN and in 5.7.2 the Net::Ping::External may be
389 integrated to Perl.
390 · The "open" pragma allows layers other than ":raw" and ":crlf" when
392 using PerlIO.
393 · POSIX::sigaction() is now much more flexible and robust. You can
395 now install coderef handlers, 'DEFAULT', and 'IGNORE' handlers,
396 installing new handlers was not atomic.
397 · The Test module has been significantly enhanced. Its use is
399 greatly recommended for module writers.
400 · The utf8:: name space (as in the pragma) provides various Perl-
402 callable functions to provide low level access to Perl's internal
403 Unicode representation. At the moment only length() has been
404 implemented.
405 The following modules have been upgraded from the versions at CPAN:
407 CPAN, CGI, DB_File, File::Temp, Getopt::Long, Pod::Man, Pod::Text,
408 Storable, Text-Tabs+Wrap.
409
411 · Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm (
412 http://burtleburtle.net/bob/hash/doobs.html ). This algorithm is
413 reasonably fast while producing a much better spread of values than
414 the old hashing algorithm (originally by Chris Torek, later tweaked
415 by Ilya Zakharevich). Hash values output from the algorithm on a
416 hash of all 3-char printable ASCII keys comes much closer to
417 passing the DIEHARD random number generation tests. According to
418 perlbench, this change has not affected the overall speed of Perl.
419 · unshift() should now be noticeably faster.
421
423 · h2xs now produces template README.
424 · s2p has been completely rewritten in Perl. (It is in fact a full
426 implementation of sed in Perl.)
427 · xsubpp now supports OUT keyword.
429
431 perlclib
432 Internal replacements for standard C library functions. (Interesting
433 only for extension writers and Perl core hackers.)
434 perliol
436 Internals of PerlIO with layers.
437 README.aix
439 Documentation on compiling Perl on AIX has been added. AIX has several
440 different C compilers and getting the right patch level is essential.
441 On install README.aix will be installed as perlaix.
442 README.bs2000
444 Documentation on compiling Perl on the POSIX-BC platform (an EBCDIC
445 mainframe environment) has been added.
446 This was formerly known as README.posix-bc but the name was considered
448 to be too confusing (it has nothing to do with the POSIX module or the
449 POSIX standard). On install README.bs2000 will be installed as
450 perlbs2000.
451 README.macos
453 In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been
454 synchronised with the standard Perl sources. To compile MacPerl some
455 additional steps are required, and this file documents those steps. On
456 install README.macos will be installed as perlmacos.
457 README.mpeix
459 The README.mpeix has been podified, which means that this information
460 about compiling and using Perl on the MPE/iX miniframe platform will be
461 installed as perlmpeix.
462 README.solaris
464 README.solaris has been created and Solaris wisdom from elsewhere in
465 the Perl documentation has been collected there. On install
466 README.solaris will be installed as perlsolaris.
467 README.vos
469 The README.vos has been podified, which means that this information
470 about compiling and using Perl on the Stratus VOS miniframe platform
471 will be installed as perlvos.
472 Porting/repository.pod
474 Documentation on how to use the Perl source repository has been added.
475
477 · Because PerlIO is now the default on most platforms, "-perlio"
478 doesn't get appended to the $Config{archname} (also known as $^O)
479 anymore. Instead, if you explicitly choose not to use perlio
480 (Configure command line option -Uuseperlio), you will get "-stdio"
481 appended.
482 · Another change related to the architecture name is that "-64all"
484 (-Duse64bitall, or "maximally 64-bit") is appended only if your
485 pointers are 64 bits wide. (To be exact, the use64bitall is
486 ignored.)
487 · APPLLIB_EXP, a less-know configuration-time definition, has been
489 documented. It can be used to prepend site-specific directories to
490 Perl's default search path (@INC), see INSTALL for information.
491 · Building Berkeley DB3 for compatibility modes for DB, NDBM, and
493 ODBM has been documented in INSTALL.
494 · If you are on IRIX or Tru64 platforms, new profiling/debugging
496 options have been added, see perlhack for more information about
497 pixie and Third Degree.
498 New Or Improved Platforms
500 For the list of platforms known to support Perl, see "Supported
501 Platforms" in perlport.
502 · AIX dynamic loading should be now better supported.
504 · After a long pause, AmigaOS has been verified to be happy with
506 Perl.
507 · EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA)
509 have been regained. Many test suite tests still fail and the co-
510 existence of Unicode and EBCDIC isn't quite settled, but the
511 situation is much better than with Perl 5.6. See perlos390,
512 perlbs2000 (for POSIX-BC), and perlvmesa for more information.
513 · Building perl with -Duseithreads or -Duse5005threads now works
515 under HP-UX 10.20 (previously it only worked under 10.30 or later).
516 You will need a thread library package installed. See README.hpux.
517 · Mac OS Classic (MacPerl has of course been available since perl
519 5.004 but now the source code bases of standard Perl and MacPerl
520 have been synchronised)
521 · NCR MP-RAS is now supported.
523 · NonStop-UX is now supported.
525 · Amdahl UTS is now supported.
527 · z/OS (formerly known as OS/390, formerly known as MVS OE) has now
529 support for dynamic loading. This is not selected by default,
530 however, you must specify -Dusedl in the arguments of Configure.
531 Generic Improvements
533 · Configure no longer includes the DBM libraries (dbm, gdbm, db,
534 ndbm) when building the Perl binary. The only exception to this is
535 SunOS 4.x, which needs them.
536 · Some new Configure symbols, useful for extension writers:
538 d_cmsghdr
540 For struct cmsghdr.
541 d_fcntl_can_lock
543 Whether fcntl() can be used for file locking.
544 d_fsync
546 d_getitimer
547 d_getpagsz
548 For getpagesize(), though you should prefer
549 POSIX::sysconf(_SC_PAGE_SIZE))
550 d_msghdr_s
552 For struct msghdr.
553 need_va_copy
555 Whether one needs to use Perl_va_copy() to copy varargs.
556 d_readv
558 d_recvmsg
559 d_sendmsg
560 sig_size
561 The number of elements in an array needed to hold all the
562 available signals.
563 d_sockatmark
565 d_strtoq
566 d_u32align
567 Whether one needs to access character data aligned by U32
568 sized pointers.
569 d_ualarm
571 d_usleep
572 · Removed Configure symbols: the PDP-11 memory model settings: huge,
573 large, medium, models.
574 · SOCKS support is now much more robust.
576 · If your file system supports symbolic links you can build Perl
578 outside of the source directory by
579 mkdir perl/build/directory
581 cd perl/build/directory
582 sh /path/to/perl/source/Configure -Dmksymlinks ...
583 This will create in perl/build/directory a tree of symbolic links
585 pointing to files in /path/to/perl/source. The original files are
586 left unaffected. After Configure has finished you can just say
587 make all test
589 and Perl will be built and tested, all in perl/build/directory.
591
593 Numerous memory leaks and uninitialized memory accesses have been
594 hunted down. Most importantly anonymous subs used to leak quite a bit.
595 · chop(@list) in list context returned the characters chopped in
597 reverse order. This has been reversed to be in the right order.
598 · The order of DESTROYs has been made more predictable.
600 · mkdir() now ignores trailing slashes in the directory name, as
602 mandated by POSIX.
603 · Attributes (like :shared) didn't work with our().
605 · The PERL5OPT environment variable (for passing command line
607 arguments to Perl) didn't work for more than a single group of
608 options.
609 · The tainting behaviour of sprintf() has been rationalized. It does
611 not taint the result of floating point formats anymore, making the
612 behaviour consistent with that of string interpolation.
613 · All but the first argument of the IO syswrite() method are now
615 optional.
616 · Tie::ARRAY SPLICE method was broken.
618 · vec() now tries to work with characters <= 255 when possible, but
620 it leaves higher character values in place. In that case, if vec()
621 was used to modify the string, it is no longer considered to be
622 utf8-encoded.
623 Platform Specific Changes and Fixes
625 · Linux previously had problems related to sockaddrlen when using
626 accept(), revcfrom() (in Perl: recv()), getpeername(), and
627 getsockname().
628 · Previously DYNIX/ptx had problems in its Configure probe for non-
630 blocking I/O.
631 · Windows
633 · Borland C++ v5.5 is now a supported compiler that can build
635 Perl. However, the generated binaries continue to be
636 incompatible with those generated by the other supported
637 compilers (GCC and Visual C++).
638 · Win32::GetCwd() correctly returns C:\ instead of C: when at
640 the drive root. Other bugs in chdir() and Cwd::cwd() have
641 also been fixed.
642 · Duping socket handles with open(F, ">&MYSOCK") now works
644 under Windows 9x.
645 · HTML files will be installed in c:\perl\html instead of
647 c:\perl\lib\pod\html
648 · The makefiles now provide a single switch to bulk-enable
650 all the features enabled in ActiveState ActivePerl (a
651 popular binary distribution).
652
654 Two new debugging options have been added: if you have compiled your
655 Perl with debugging, you can use the -DT and -DR options to trace
656 tokenising and to add reference counts to displaying variables,
657 respectively.
658 · If an attempt to use a (non-blessed) reference as an array index is
660 made, a warning is given.
661 · "push @a;" and "unshift @a;" (with no values to push or unshift)
663 now give a warning. This may be a problem for generated and
664 eval'ed code.
665
667 · Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
668 For the full list of the available APIs see perlapi.
669 · dTHR and djSP have been obsoleted; the former removed (because it's
671 a no-op) and the latter replaced with dSP.
672 · Perl now uses system malloc instead of Perl malloc on all 64-bit
674 platforms, and even in some not-always-64-bit platforms like AIX,
675 IRIX, and Solaris. This change breaks backward compatibility but
676 Perl's malloc has problems with large address spaces and also the
677 speed of vendors' malloc is generally better in large address space
678 machines (Perl's malloc is mostly tuned for space).
679
681 Many new tests have been added. The most notable is probably the
682 lib/1_compile: it is very notable because running it takes quite a long
683 time. It test compiles all the Perl modules in the distribution.
684 Please be patient.
685
687 Note that unlike other sections in this document (which describe
688 changes since 5.7.0) this section is cumulative containing known
689 problems for all the 5.7 releases.
690 AIX vac 5.0.0.0 May Produce Buggy Code For Perl
692 The AIX C compiler vac version 5.0.0.0 may produce buggy code,
693 resulting in few random tests failing, but when the failing tests are
694 run by hand, they succeed. We suggest upgrading to at least vac
695 version 5.0.1.0, that has been known to compile Perl correctly. "lslpp
696 -L|grep vac.C" will tell you the vac version.
697 lib/ftmp-security tests warn 'system possibly insecure'
699 Don't panic. Read INSTALL 'make test' section instead.
700 lib/io_multihomed Fails In LP64-Configured HP-UX
702 The lib/io_multihomed test may hang in HP-UX if Perl has been
703 configured to be 64-bit. Because other 64-bit platforms do not hang in
704 this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
705 test attempts to create and connect to "multihomed" sockets (sockets
706 which have multiple IP addresses).
707 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
709 If perl is configured with -Duse64bitall, the successful result of the
710 subtest 10 of lib/posix may arrive before the successful result of the
711 subtest 9, which confuses the test harness so much that it thinks the
712 subtest 9 failed.
713 lib/b test 19
715 The test fails on various platforms (PA64 and IA64 are known), but the
716 exact cause is still being investigated.
717 Linux With Sfio Fails op/misc Test 48
719 No known fix.
720 sigaction test 13 in VMS
722 The test is known to fail; whether it's because of VMS of because of
723 faulty test is not known.
724 sprintf tests 129 and 130
726 The op/sprintf tests 129 and 130 are known to fail on some platforms.
727 Examples include any platform using sfio, and Compaq/Tandem's NonStop-
728 UX. The failing platforms do not comply with the ANSI C Standard, line
729 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
730 something else than "1" and "-1" when formatting 0.6 and -0.6 using the
731 printf format "%.0f", most often they produce "0" and "-0".)
732 Failure of Thread tests
734 The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
735 fundamental problems in the 5.005 threading implementation. These are
736 not new failures--Perl 5.005_0x has the same bugs, but didn't have
737 these tests. (Note that support for 5.005-style threading remains
738 experimental.)
739 Localising a Tied Variable Leaks Memory
741 use Tie::Hash;
742 tie my %tie_hash => 'Tie::StdHash';
743 ...
745 local($tie_hash{Foo}) = 1; # leaks
747 Code like the above is known to leak memory every time the local() is
749 executed.
750 Self-tying of Arrays and Hashes Is Forbidden
752 Self-tying of arrays and hashes is broken in rather deep and hard-to-
753 fix ways. As a stop-gap measure to avoid people from getting
754 frustrated at the mysterious results (core dumps, most often) it is for
755 now forbidden (you will get a fatal error even from an attempt).
756 Building Extensions Can Fail Because Of Largefiles
758 Some extensions like mod_perl are known to have issues with
759 `largefiles', a change brought by Perl 5.6.0 in which file offsets
760 default to 64 bits wide, where supported. Modules may fail to compile
761 at all or compile and work incorrectly. Currently there is no good
762 solution for the problem, but Configure now provides appropriate non-
763 largefile ccflags, ldflags, libswanted, and libs in the %Config hash
764 (e.g., $Config{ccflags_nolargefiles}) so the extensions that are having
765 problems can try configuring themselves without the largefileness.
766 This is admittedly not a clean solution, and the solution may not even
767 work at all. One potential failure is whether one can (or, if one can,
768 whether it's a good idea) link together at all binaries with different
769 ideas about file offsets, all this is platform-dependent.
770 The Compiler Suite Is Still Experimental
772 The compiler suite is slowly getting better but is nowhere near working
773 order yet.
774
776 If you find what you think is a bug, you might check the articles
777 recently posted to the comp.lang.perl.misc newsgroup and the perl bug
778 database at http://bugs.perl.org/ There may also be information at
779 http://www.perl.com/perl/ , the Perl Home Page.
780 If you believe you have an unreported bug, please run the perlbug
782 program included with your release. Be sure to trim your bug down to a
783 tiny but sufficient test case. Your bug report, along with the output
784 of "perl -V", will be sent off to perlbug@perl.org to be analysed by
785 the Perl porting team.
786
788 The Changes file for exhaustive details on what changed.
789 The INSTALL file for how to build Perl.
791 The README file for general stuff.
793 The Artistic and Copying files for copyright information.
795
797 Written by Jarkko Hietaniemi <jhi@iki.fi>, with many contributions from
798 The Perl Porters and Perl Users submitting feedback and patches.
799 Send omissions or corrections to <perlbug@perl.org>.
801perl v5.12.4 2011-06-01 PERL571DELTA(1)