1Inline(3) User Contributed Perl Documentation Inline(3)
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3
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6 Inline - Write Perl Subroutines in Other Programming Languages
7
9 This document describes Inline version 0.86.
10
12 use Inline C;
13
14 print "9 + 16 = ", add(9, 16), "\n";
15 print "9 - 16 = ", subtract(9, 16), "\n";
16
17 __END__
18 __C__
19 int add(int x, int y) {
20 return x + y;
21 }
22
23 int subtract(int x, int y) {
24 return x - y;
25 }
26
28 The Inline module allows you to put source code from other programming
29 languages directly "inline" in a Perl script or module. The code is
30 automatically compiled as needed, and then loaded for immediate access
31 from Perl.
32
33 Inline saves you from the hassle of having to write and compile your
34 own glue code using facilities like XS or SWIG. Simply type the code
35 where you want it and run your Perl as normal. All the hairy details
36 are handled for you. The compilation and installation of your code
37 chunks all happen transparently; all you will notice is the delay of
38 compilation on the first run.
39
40 The Inline code only gets compiled the first time you run it (or
41 whenever it is modified) so you only take the performance hit once.
42 Code that is Inlined into distributed modules (like on the CPAN) will
43 get compiled when the module is installed, so the end user will never
44 notice the compilation time.
45
46 Best of all, it works the same on both Unix and Microsoft Windows. See
47 Inline- Support for support information.
48
49 Why Inline?
50 Do you want to know "Why would I use other languages in Perl?" or "Why
51 should I use Inline to do it?"? I'll try to answer both.
52
53 Why would I use other languages in Perl?
54 The most obvious reason is performance. For an interpreted
55 language, Perl is very fast. Many people will say "Anything Perl
56 can do, C can do faster". (They never mention the development time
57 :-) Anyway, you may be able to remove a bottleneck in your Perl
58 code by using another language, without having to write the entire
59 program in that language. This keeps your overall development time
60 down, because you're using Perl for all of the non-critical code.
61
62 Another reason is to access functionality from existing API-s that
63 use the language. Some of this code may only be available in binary
64 form. But by creating small subroutines in the native language, you
65 can "glue" existing libraries to your Perl. As a user of the CPAN,
66 you know that code reuse is a good thing. So why throw away those
67 Fortran libraries just yet?
68
69 If you are using Inline with the C language, then you can access
70 the full internals of Perl itself. This opens up the floodgates to
71 both extreme power and peril.
72
73 Maybe the best reason is "Because you want to!". Diversity keeps
74 the world interesting. TMTOWTDI!
75
76 Why should I use Inline to do it?
77 There are already two major facilities for extending Perl with C.
78 They are XS and SWIG. Both are similar in their capabilities, at
79 least as far as Perl is concerned. And both of them are quite
80 difficult to learn compared to Inline.
81
82 There is a big fat learning curve involved with setting up and
83 using the XS environment. You need to get quite intimate with the
84 following docs:
85
86 • perlxs
87
88 • perlxstut
89
90 • perlapi
91
92 • perlguts
93
94 • perlmod
95
96 • h2xs
97
98 • xsubpp
99
100 • ExtUtils::MakeMaker
101
102 With Inline you can be up and running in minutes. There is a C
103 Cookbook with lots of short but complete programs that you can
104 extend to your real-life problems. No need to learn about the
105 complicated build process going on in the background. You don't
106 even need to compile the code yourself. Inline takes care of every
107 last detail except writing the C code.
108
109 Perl programmers cannot be bothered with silly things like
110 compiling. "Tweak, Run, Tweak, Run" is our way of life. Inline does
111 all the dirty work for you.
112
113 Another advantage of Inline is that you can use it directly in a
114 script. You can even use it in a Perl one-liner. With XS and SWIG,
115 you always set up an entirely separate module. Even if you only
116 have one or two functions. Inline makes easy things easy, and hard
117 things possible. Just like Perl.
118
119 Finally, Inline supports several programming languages (not just C
120 and C++). As of this writing, Inline has support for C, C++, Java,
121 Python, Ruby, Tcl, Assembler, Basic, Guile, Befunge, Octave, Awk,
122 BC, TT (Template Toolkit), WebChat and even PERL. New Inline
123 Language Support Modules (ILSMs) are regularly being added. See
124 Inline-API for details on how to create your own ILSM.
125
127 Inline is a little bit different than most of the Perl modules that you
128 are used to. It doesn't import any functions into your namespace and it
129 doesn't have any object oriented methods. Its entire interface (with
130 two minor exceptions) is specified through the 'use Inline ...'
131 command.
132
133 This section will explain all of the different ways to "use Inline". If
134 you want to begin using C with Inline immediately, see
135 Inline::C-Cookbook.
136
137 The Basics
138 The most basic form for using Inline is:
139
140 use Inline X => "X source code";
141
142 where 'X' is one of the supported Inline programming languages. The
143 second parameter identifies the source code that you want to bind to
144 Perl. The source code can be specified using any of the following
145 syntaxes:
146
147 The DATA Keyword.
148 use Inline Java => 'DATA';
149
150 # Perl code goes here ...
151
152 __DATA__
153 __Java__
154 /* Java code goes here ... */
155
156 The easiest and most visually clean way to specify your source code
157 in an Inline Perl program is to use the special "DATA" keyword.
158 This tells Inline to look for a special marker in your "DATA"
159 filehandle's input stream. In this example the special marker is
160 "__Java__", which is the programming language surrounded by double
161 underscores.
162
163 In case you've forgotten, the "DATA" pseudo file is comprised of
164 all the text after the "__END__" or "__DATA__" section of your
165 program. If you're working outside the "main" package, you'd best
166 use the "__DATA__" marker or else Inline will not find your code.
167
168 Using this scheme keeps your Perl code at the top, and all the ugly
169 Java stuff down below where it belongs. This is visually clean and
170 makes for more maintainable code. An excellent side benefit is that
171 you don't have to escape any characters like you might in a Perl
172 string. The source code is verbatim. For these reasons, I prefer
173 this method the most.
174
175 The only problem with this style is that since Perl can't read the
176 "DATA" filehandle until runtime, it obviously can't bind your
177 functions until runtime. The net effect of this is that you can't
178 use your Inline functions as barewords (without predeclaring them)
179 because Perl has no idea they exist during compile time.
180
181 The FILE and BELOW keywords.
182 use Inline::Files;
183 use Inline Java => 'file';
184
185 # Perl code goes here ...
186
187 __JAVA__
188 /* Java code goes here ... */
189
190 This is the newest method of specifying your source code. It makes
191 use of the Perl module "Inline::Files" written by Damian Conway.
192 The basic style and meaning are the same as for the "DATA" keyword,
193 but there are a few syntactic and semantic twists.
194
195 First, you must say 'use Inline::Files' before you 'use Inline'
196 code that needs those files. The special '"DATA"' keyword is
197 replaced by either '"file"' or '"below"'. This allows for the bad
198 pun idiom of:
199
200 use Inline C => 'below';
201
202 You can omit the "__DATA__" tag now. Inline::Files is a source
203 filter that will remove these sections from your program before
204 Perl compiles it. They are then available for Inline to make use
205 of. And since this can all be done at compile time, you don't have
206 to worry about the caveats of the 'DATA' keyword.
207
208 This module has a couple small gotchas. Since Inline::Files only
209 recognizes file markers with capital letters, you must specify the
210 capital form of your language name. Also, there is a startup time
211 penalty for using a source code filter.
212
213 At this point Inline::Files is alpha software and use of it is
214 experimental. Inline's integration of this module is also
215 fledgling at the time being. One of things I plan to do with
216 Inline::Files is to get line number info so when an extension
217 doesn't compile, the error messages will point to the correct
218 source file and line number.
219
220 My best advice is to use Inline::Files for testing (especially as
221 support for it improves), but use DATA for production and
222 distributed/CPAN code.
223
224 Strings
225 use Inline Java => <<'END';
226
227 /* Java code goes here ... */
228 END
229
230 # Perl code goes here ...
231
232 You also just specify the source code as a single string. A handy
233 way to write the string is to use Perl's "here document" style of
234 quoting. This is ok for small functions but can get unwieldy in the
235 large. On the other hand, the string variant probably has the least
236 startup penalty and all functions are bound at compile time.
237
238 If you wish to put the string into a scalar variable, please be
239 aware that the "use" statement is a compile time directive. As
240 such, all the variables it uses must also be set at compile time,
241 "before" the 'use Inline' statement. Here is one way to do it:
242
243 my $code;
244 BEGIN {
245 $code = <<END;
246
247 /* Java code goes here ... */
248 END
249 }
250 use Inline Java => $code;
251
252 # Perl code goes here ...
253
254 The bind() Function
255 An alternative to using the BEGIN block method is to specify the
256 source code at run time using the 'Inline->bind()' method. (This is
257 one of the interface exceptions mentioned above) The "bind()"
258 method takes the same arguments as 'use Inline ...'.
259
260 my $code = <<END;
261
262 /* Java code goes here ... */
263 END
264
265 Inline->bind(Java => $code);
266
267 You can think of "bind()" as a way to "eval()" code in other
268 programming languages.
269
270 Although bind() is a powerful feature, it is not recommended for
271 use in Inline based modules. In fact, it won't work at all for
272 installable modules. See instructions below for creating modules
273 with Inline.
274
275 Other Methods
276 The source code for Inline can also be specified as an external
277 filename, a reference to a subroutine that returns source code, or
278 a reference to an array that contains lines of source code. (Note
279 that if the external source file is in the current directory it
280 must be specified with a leading '.' - ie '.file.ext' instead of
281 simply 'file.ext'.) These methods are less frequently used but may
282 be useful in some situations.
283
284 For instance, to load your C++ code from a file named the same as
285 your perl module with a swapped file extension, you can use:
286
287 use Inline CPP => (__FILE__ =~ s/\.pm$/.cpp/r);
288
289 Shorthand
290 If you are using the 'DATA' or 'file' methods described above and
291 there are no extra parameters, you can omit the keyword altogether.
292 For example:
293
294 use Inline 'Java';
295
296 # Perl code goes here ...
297
298 __DATA__
299 __Java__
300 /* Java code goes here ... */
301
302 or
303
304 use Inline::Files;
305 use Inline 'Java';
306
307 # Perl code goes here ...
308
309 __JAVA__
310 /* Java code goes here ... */
311
312 More about the DATA Section
313 If you are writing a module, you can also use the DATA section for POD
314 and AutoLoader subroutines. Just be sure to put them before the first
315 Inline marker. If you install the helper module "Inline::Filters", you
316 can even use POD inside your Inline code. You just have to specify a
317 filter to strip it out.
318
319 You can also specify multiple Inline sections, possibly in different
320 programming languages. Here is another example:
321
322 # The module Foo.pm
323 package Foo;
324 use AutoLoader;
325
326 use Inline C;
327 use Inline C => DATA => filters => 'Strip_POD';
328 use Inline Python;
329
330 1;
331
332 __DATA__
333
334 sub marine {
335 # This is an autoloaded subroutine
336 }
337
338 =head1 External subroutines
339
340 =cut
341
342 __C__
343 /* First C section */
344
345 __C__
346 /* Second C section */
347 =head1 My C Function
348
349 Some POD doc.
350
351 =cut
352
353 __Python__
354 """A Python Section"""
355
356 An important thing to remember is that you need to have one "use Inline
357 Foo => 'DATA'" for each "__Foo__" marker, and they must be in the same
358 order. This allows you to apply different configuration options to
359 each section.
360
361 Configuration Options
362 Inline tries to do the right thing as often as possible. But sometimes
363 you may need to override the default actions. This is easy to do.
364 Simply list the Inline configuration options after the regular Inline
365 parameters. All configuration options are specified as (key, value)
366 pairs.
367
368 use Inline (C => 'DATA',
369 directory => './inline_dir',
370 libs => '-lfoo',
371 inc => '-I/foo/include',
372 prefix => 'XXX_',
373 warnings => 0,
374 );
375
376 You can also specify the configuration options on a separate Inline
377 call like this:
378
379 use Inline (C => Config =>
380 directory => './inline_dir',
381 libs => '-lfoo',
382 inc => '-I/foo/include',
383 prefix => 'XXX_',
384 warnings => 0,
385 );
386 use Inline C => <<'END_OF_C_CODE';
387
388 The special keyword 'Config' tells Inline that this is a configuration-
389 only call. No source code will be compiled or bound to Perl.
390
391 If you want to specify global configuration options that don't apply to
392 a particular language, just leave the language out of the call. Like
393 this:
394
395 use Inline Config => warnings => 0;
396
397 The Config options are inherited and additive. You can use as many
398 Config calls as you want. And you can apply different options to
399 different code sections. When a source code section is passed in,
400 Inline will apply whichever options have been specified up to that
401 point. Here is a complex configuration example:
402
403 use Inline (Config =>
404 directory => './inline_dir',
405 );
406 use Inline (C => Config =>
407 libs => '-lglobal',
408 );
409 use Inline (C => 'DATA', # First C Section
410 libs => ['-llocal1', '-llocal2'],
411 );
412 use Inline (Config =>
413 warnings => 0,
414 );
415 use Inline (Python => 'DATA', # First Python Section
416 libs => '-lmypython1',
417 );
418 use Inline (C => 'DATA', # Second C Section
419 libs => [undef, '-llocal3'],
420 );
421
422 The first "Config" applies to all subsequent calls. The second "Config"
423 applies to all subsequent "C" sections (but not "Python" sections). In
424 the first "C" section, the external libraries "global", "local1" and
425 "local2" are used. (Most options allow either string or array ref
426 forms, and do the right thing.) The "Python" section does not use the
427 "global" library, but does use the same "DIRECTORY", and has warnings
428 turned off. The second "C" section only uses the "local3" library.
429 That's because a value of "undef" resets the additive behavior.
430
431 The "directory" and "warnings" options are generic Inline options. All
432 other options are language specific. To find out what the "C" options
433 do, see "Inline::C".
434
435 On and Off
436 If a particular config option has value options of 1 and 0, you can use
437 the 'enable' and 'disable' modifiers. In other words, this:
438
439 use Inline Config =>
440 force_build => 1,
441 clean_after_build => 0;
442
443 could be reworded as:
444
445 use Inline Config =>
446 enable => force_build =>
447 disable => clean_after_build;
448
449 Playing 'with' Others
450 Inline has a special configuration syntax that tells it to get more
451 configuration options from other Perl modules. Here is an example:
452
453 use Inline with => 'Event';
454
455 This tells Inline to load the module "Event.pm" and ask it for
456 configuration information. Since "Event" has a C API of its own, it can
457 pass Inline all of the information it needs to be able to use "Event" C
458 callbacks seamlessly.
459
460 That means that you don't need to specify the typemaps, shared
461 libraries, include files and other information required to get this to
462 work.
463
464 You can specify a single module or a list of them. Like:
465
466 use Inline with => qw(Event Foo Bar);
467
468 Currently, modules that works with Inline include "Event", "PDL", and
469 those that use "Alien::Build".
470
471 In order to make your module work with Inline in this way, your module
472 needs to provide a class method called "Inline" that takes an Inline
473 language as a parameter (e.g. "C"), and returns a reference to a hash
474 with configuration information that is acceptable to the relevant ILSM.
475 For C, see C Configuration Options. E.g.:
476
477 my $confighashref = Event->Inline('C'); # only supports C in 1.21
478 # hashref contains keys INC, TYPEMAPS, MYEXTLIB, AUTO_INCLUDE, BOOT
479
480 If your module uses ExtUtils::Depends version 0.400 or higher, your
481 module only needs this:
482
483 package Module;
484 use autouse Module::Install::Files => qw(Inline);
485
486 Inline Shortcuts
487 Inline lets you set many configuration options from the command line.
488 These options are called 'shortcuts'. They can be very handy,
489 especially when you only want to set the options temporarily, for say,
490 debugging.
491
492 For instance, to get some general information about your Inline code in
493 the script "Foo.pl", use the command:
494
495 perl -MInline=info Foo.pl
496
497 If you want to force your code to compile, even if its already done,
498 use:
499
500 perl -MInline=force Foo.pl
501
502 If you want to do both, use:
503
504 perl -MInline=info -MInline=force Foo.pl
505
506 or better yet:
507
508 perl -MInline=info,force Foo.pl
509
510 The Inline 'directory'
511 Inline needs a place to build your code and to install the results of
512 the build. It uses a single directory named '.Inline/' under normal
513 circumstances. If you create this directory in your home directory, the
514 current directory or in the directory where your program resides,
515 Inline will find and use it. You can also specify it in the environment
516 variable "PERL_INLINE_DIRECTORY" or directly in your program, by using
517 the "directory" keyword option. If Inline cannot find the directory in
518 any of these places it will create a '_Inline/' directory in either
519 your current directory or the directory where your script resides.
520
521 One of the key factors to using Inline successfully, is understanding
522 this directory. When developing code it is usually best to create this
523 directory (or let Inline do it) in your current directory. Remember
524 that there is nothing sacred about this directory except that it holds
525 your compiled code. Feel free to delete it at any time. Inline will
526 simply start from scratch and recompile your code on the next run. If
527 you have several programs that you want to force to recompile, just
528 delete your '.Inline/' directory.
529
530 It is probably best to have a separate '.Inline/' directory for each
531 project that you are working on. You may want to keep stable code in
532 the <.Inline/> in your home directory. On multi-user systems, each user
533 should have their own '.Inline/' directories. It could be a security
534 risk to put the directory in a shared place like "/tmp/".
535
536 Debugging Inline Errors
537 All programmers make mistakes. When you make a mistake with Inline,
538 like writing bad C code, you'll get a big error report on your screen.
539 This report tells you where to look to do the debugging. Some languages
540 may also dump out the error messages generated from the build.
541
542 When Inline needs to build something it creates a subdirectory under
543 your "DIRECTORY/build/" directory. This is where it writes all the
544 components it needs to build your extension. Things like XS files,
545 Makefiles and output log files.
546
547 If everything goes OK, Inline will delete this subdirectory. If there
548 is an error, Inline will leave the directory intact and print its
549 location. The idea is that you are supposed to go into that directory
550 and figure out what happened.
551
552 Read the doc for your particular Inline Language Support Module for
553 more information.
554
555 The 'config' Registry File
556 Inline keeps a cached file of all of the Inline Language Support
557 Module's meta data in a file called "config". This file can be found in
558 your "directory" directory. If the file does not exist, Inline creates
559 a new one. It will search your system for any module beginning with
560 "Inline::". It will then call that module's "register()" method to get
561 useful information for future invocations.
562
563 Whenever you add a new ILSM, you should delete this file so that Inline
564 will auto-discover your newly installed language module. (This should
565 no longer be necessary as of Inline-0.49.)
566
568 This section lists all of the generic Inline configuration options. For
569 language specific configuration, see the doc for that language.
570
571 "directory"
572 The "directory" config option is the directory that Inline uses to
573 both build and install an extension.
574
575 Normally Inline will search in a bunch of known places for a
576 directory called '.Inline/'. Failing that, it will create a
577 directory called '_Inline/'
578
579 If you want to specify your own directory, use this configuration
580 option.
581
582 Note that you must create the "directory" directory yourself.
583 Inline will not do it for you.
584
585 "name"
586 You can use this option to set the name of your Inline extension
587 object module. For example:
588
589 use Inline C => 'DATA',
590 name => 'Foo::Bar';
591
592 would cause your C code to be compiled in to the object:
593
594 lib/auto/Foo/Bar/Bar.so
595 lib/auto/Foo/Bar/Bar.inl
596
597 (The .inl component contains dependency information to make sure
598 the source code is in sync with the executable)
599
600 If you don't use "name", Inline will pick a name for you based on
601 your program name or package name. In this case, Inline will also
602 enable the "autoname" option which mangles in a small piece of the
603 MD5 fingerprint into your object name, to make it unique.
604
605 "autoname"
606 This option is enabled whenever the "name" parameter is not
607 specified. To disable it say:
608
609 use Inline C => 'DATA',
610 disable => 'autoname';
611
612 "autoname" mangles in enough of the MD5 fingerprint to make your
613 module name unique. Objects created with "autoname" will never get
614 replaced. That also means they will never get cleaned up
615 automatically.
616
617 "autoname" is very useful for small throw away scripts. For more
618 serious things, always use the "name" option.
619
620 "version"
621 Specifies the version number of the Inline extension object. It is
622 used only for modules, and it must match the global variable
623 $VERSION. Additionally, this option should used if (and only if) a
624 module is being set up to be installed permanently into the Perl
625 sitelib tree using Inline::MakeMaker (NOT used by Inline::Module).
626 Inline will croak if you use it otherwise.
627
628 The presence of the "version" parameter is the official way to let
629 Inline know that your code is an installable/installed module.
630 Inline will never generate an object in the temporary cache
631 ("_Inline/" directory) if "version" is set. It will also never try
632 to recompile a module that was installed into someone's Perl site
633 tree.
634
635 So the basic rule is develop without "version", and deliver with
636 "version".
637
638 "with"
639 "with" can also be used as a configuration option instead of using
640 the special 'with' syntax. Do this if you want to use different
641 sections of Inline code with different modules. (Probably a very
642 rare usage)
643
644 use Event;
645 use Inline C => DATA => with => 'Event';
646
647 Modules specified using the config form of "with" will not be
648 automatically required. You must "use" them yourself.
649
650 "using"
651 You can override modules that get used by ILSMs with the "using"
652 option. This is typically used to override the default parser for
653 Inline::C, but might be used by any ILSM for any purpose.
654
655 use Inline config => using => '::Parser::RecDescent';
656 use Inline C => '...';
657
658 This would tell Inline::C to use Inline::C::Parser::RecDescent.
659
660 "global_load"
661 This option is for compiled languages only. It tells Inline to tell
662 DynaLoader to load an object file in such a way that its symbols
663 can be dynamically resolved by other object files. May not work on
664 all platforms. See the "global" shortcut below.
665
666 "untaint"
667 You can use this option whenever you use Perl's "-T" switch, for
668 taint checking. This option tells Inline to blindly untaint all
669 tainted variables. (This is generally considered to be an
670 appallingly insecure thing to do, and not to be recommended - but
671 the option is there for you to use if you want. Please consider
672 using something other than Inline for scripts that need taint
673 checking.) It also turns on "safemode" by default. See the
674 "untaint" shortcut below. You will see warnings about blindly
675 untainting fields in both %ENV and Inline objects. If you want to
676 silence these warnings, set the Config option "no_untaint_warn" =>
677 1. There can be some problems untainting Inline scripts where older
678 versions of Cwd, such as those that shipped with early versions of
679 perl-5.8 (and earlier), are installed. Updating Cwd will probably
680 solve these problems.
681
682 safemode
683 Perform extra safety checking, in an attempt to thwart malicious
684 code. This option cannot guarantee security, but it does turn on
685 all the currently implemented checks. (Currently, the only
686 "currently implemented check" is to ensure that the "directory"
687 option has also been used.)
688
689 There is a slight startup penalty by using "safemode". Also, using
690 "untaint" automatically turns this option on. If you need your code
691 to start faster under "-T" (taint) checking, you'll need to turn
692 this option off manually. Only do this if you are not worried
693 about security risks. See the "unsafe" shortcut below.
694
695 "force_build"
696 Makes Inline build (compile) the source code every time the program
697 is run. The default is 0. See the "force" shortcut below.
698
699 "build_noisy"
700 Tells ILSMs that they should dump build messages to the terminal
701 rather than be silent about all the build details.
702
703 "build_timers"
704 Tells ILSMs to print timing information about how long each build
705 phase took. Usually requires "Time::HiRes".
706
707 "clean_after_build"
708 Tells Inline to clean up the current build area if the build was
709 successful. Sometimes you want to "disable" this for debugging.
710 Default is 1. See the "noclean" shortcut below.
711
712 "clean_build_area"
713 Tells Inline to clean up the old build areas within the entire
714 Inline "directory". Default is 0. See the "clean" shortcut below.
715
716 "print_info"
717 Tells Inline to print various information about the source code.
718 Default is 0. See the "info" shortcut below.
719
720 "print_version"
721 Tells Inline to print version info about itself. Default is 0. See
722 the "version" shortcut below.
723
724 "reportbug"
725 Puts Inline into 'reportbug' mode, which is what you want if you
726 desire to report a bug.
727
728 "rewrite_config_file"
729 Default is 0, but setting "rewrite_config_file => 1" will mean that
730 the existing configuration file in the Inline "directory" will be
731 overwritten. (This is useful if the existing config file is not up
732 to date as regards supported languages.)
733
734 "warnings"
735 This option tells Inline whether to print certain warnings. Default
736 is 1.
737
739 This is a list of all the shortcut configuration options currently
740 available for Inline. Specify them from the command line when running
741 Inline scripts.
742
743 perl -MInline=noclean inline_script.pl
744
745 or
746
747 perl -MInline=info,force,noclean inline_script.pl
748
749 You can specify multiple shortcuts separated by commas. They are not
750 case sensitive. You can also specify shortcuts inside the Inline
751 program like this:
752
753 use Inline 'info', 'force', 'noclean';
754
755 NOTE: If a 'use Inline' statement is used to set shortcuts, it can not
756 be
757 used for additional purposes.
758
759 "clean"
760 Tells Inline to remove any build directories that may be lying
761 around in your build area. Normally these directories get removed
762 immediately after a successful build. Exceptions are when the build
763 fails, or when you use the "noclean" or "reportbug" options.
764
765 "force"
766 Forces the code to be recompiled, even if everything is up to date.
767
768 "global"
769 Turns on the "global_load" option.
770
771 "info"
772 This is a very useful option when you want to know what's going on
773 under the hood. It tells Inline to print helpful information to
774 "STDERR". Among the things that get printed is a list of which
775 Inline functions were successfully bound to Perl.
776
777 "noclean"
778 Tells Inline to leave the build files after compiling.
779
780 "noisy"
781 Use the "build_noisy" option to print messages during a build.
782
783 "reportbug"
784 Puts Inline into "reportbug" mode, which does special processing
785 when you want to report a bug. "reportbug" also automatically
786 forces a build, and doesn't clean up afterwards. This is so that
787 you can tar and mail the build directory to me. "reportbug" will
788 print exact instructions on what to do. Please read and follow
789 them carefully.
790
791 NOTE: "reportbug" informs you to use the tar command. If your
792 system does not
793 have tar, please use the equivalent "zip" command.
794
795 "safe"
796 Turns "safemode" on. "untaint" will turn this on automatically.
797 While this mode performs extra security checking, it does not
798 guarantee safety.
799
800 "site_install"
801 This parameter used to be used for creating installable Inline
802 modules. It has been removed from Inline altogether and replaced
803 with a much simpler and more powerful mechanism,
804 "Inline::MakeMaker". See the section below on how to create modules
805 with Inline.
806
807 "_testing"
808 Used internally by Ct09parser.t and Ct10callback.t(in the Inline::C
809 test suite). Setting this option with Inline::C will mean that
810 files named "parser_id" and "void_test" are created in the
811 "./Inline_test" directory, creating that directory if it doesn't
812 already exist. The files (but not the "./Inline_test directory")
813 are cleaned up by calling "Inline::C::_testing_cleanup()". Also
814 used by "t/06rewrite_config.t" to trigger a warning.
815
816 "timers"
817 Turn on "build_timers" to get extra diagnostic info about builds.
818
819 "unsafe"
820 Turns "safemode" off. Use this in combination with "untaint" for
821 slightly faster startup time under "-T". Only use this if you are
822 sure the environment is safe.
823
824 "untaint"
825 Turn the "untaint" option on. Used with "-T" switch. In terms of
826 secure practices, this is definitely not a recommended way of
827 dealing with taint checking, but it's the only option currently
828 available with Inline. Use it at your own risk.
829
830 "version"
831 Tells Inline to report its release version.
832
834 The current preferred way to author CPAN modules with Inline is to use
835 Inline::Module (distributed separately). Inline ships with
836 Inline::MakeMaker, which helps you set up a Makefile.PL that invokes
837 Inline at install time to compile all the code before it gets
838 installed, but the resulting module still depends on Inline and the
839 language support module like Inline::C. In order to avoid this
840 dependency, what you really want to do is convert your distribution to
841 plain XS before uploading it to CPAN. Inline::Module fills that role,
842 and also integrates well with more modern authoring tools.
843
844 See Inline::Module for details on that approach, or continue reading
845 below for the older Inline::MakeMaker technique.
846
847 Let's say that you wanted to write a module called "Math::Simple".
848 Start by using the following command:
849
850 h2xs -PAXn Math::Simple
851
852 This will generate a bunch of files that form a skeleton of what you
853 need for a distributable module. (Read the h2xs manpage to find out
854 what the options do) Next, modify the "Simple.pm" file to look like
855 this:
856
857 package Math::Simple;
858 $VERSION = '1.23';
859
860 use base 'Exporter';
861 @EXPORT_OK = qw(add subtract);
862 use strict;
863
864 use Inline C => 'DATA',
865 version => '1.23',
866 name => 'Math::Simple';
867
868 # The following Inline->init() call is optional - see below for more info.
869 #Inline->init();
870
871 1;
872
873 __DATA__
874
875 =pod
876
877 =cut
878
879 __C__
880 int add(int x, int y) {
881 return x + y;
882 }
883
884 int subtract(int x, int y) {
885 return x - y;
886 }
887
888 The important things to note here are that you must specify a "name"
889 and "version" parameter. The "name" must match your module's package
890 name. The "version" parameter must match your module's $VERSION
891 variable and they must be considered valid by "version::parse".
892
893 NOTE: These are Inline's sanity checks to make sure you know what
894 you're doing
895 before uploading your code to CPAN. They insure that once the
896 module has
897 been installed on someone's system, the module would not get
898 automatically recompiled for any reason. This makes Inline based
899 modules
900 work in exactly the same manner as XS based ones.
901
902 Finally, you need to modify the Makefile.PL. Simply change:
903
904 use ExtUtils::MakeMaker;
905
906 to
907
908 use Inline::MakeMaker;
909
910 And, in order that the module build work correctly in the cpan shell,
911 add the following directive to the Makefile.PL's WriteMakefile():
912
913 CONFIGURE_REQUIRES => {
914 'Inline::MakeMaker' => 0.45,
915 'ExtUtils::MakeMaker' => 6.52,
916 },
917
918 This "CONFIGURE_REQUIRES" directive ensures that the cpan shell will
919 install Inline on the user's machine (if it's not already present)
920 before building your Inline-based module. Specifying of
921 "ExtUtils::MakeMaker => 6.52," is optional, and can be omitted if you
922 like. It ensures only that some harmless warnings relating to the
923 "CONFIGURE_REQUIRES" directive won't be emitted during the building of
924 the module. It also means, of course, that ExtUtils::Makemaker will
925 first be updated on the user's machine unless the user already has
926 version 6.52 or later.
927
928 If the "Inline->init();" is not done then, having installed
929 Math::Simple, a warning that "One or more DATA sections were not
930 processed by Inline" will appear when (and only when) Math::Simple is
931 loaded by a "require call. It's a harmless warning - and if you're
932 prepared to live with it, then there's no need to make the
933 "Inline->init();" call.
934
935 When the person installing "Math::Simple" does a ""make"", the
936 generated Makefile will invoke Inline in such a way that the C code
937 will be compiled and the executable code will be placed into the
938 "./blib" directory. Then when a ""make install"" is done, the module
939 will be copied into the appropriate Perl sitelib directory (which is
940 where an installed module should go).
941
942 Now all you need to do is:
943
944 perl Makefile.PL
945 make dist
946
947 That will generate the file "Math-Simple-0.20.tar.gz" which is a
948 distributable package. (It will also generate some harmless warnings in
949 relation to "CONFIGURE_REQUIRES" unless the version of your
950 ExtUtils::MakeMaker is 6.52 or later.) That's all there is to it.
951
952 IMPORTANT NOTE: Although the above steps will produce a workable
953 module, you still have a few more responsibilities as a budding new
954 CPAN author. You need to write lots of documentation and write lots of
955 tests. Take a look at some of the better CPAN modules for ideas on
956 creating a killer test harness. Actually, don't listen to me, go read
957 these:
958
959 • perldoc perlnewmod
960
961 • <http://www.cpan.org/modules/04pause.html>
962
963 • <http://www.cpan.org/modules/00modlist.long.html>
964
966 In reality, Inline just automates everything you would need to do if
967 you were going to do it by hand (using XS, etc).
968
969 Inline performs the following steps:
970
971 • Receive the Source Code
972
973 Inline gets the source code from your script or module with a
974 statements like the following:
975
976 use Inline C => "Source-Code";
977
978 or
979
980 use Inline;
981 bind Inline C => "Source-Code";
982
983 where "C" is the programming language of the source code, and
984 "Source- Code" is a string, a file name, an array reference, or the
985 special 'DATA' keyword.
986
987 Since Inline is coded in a ""use"" statement, everything is done
988 during Perl's compile time. If anything needs to be done that will
989 affect the "Source- Code", it needs to be done in a "BEGIN" block
990 that is before the ""use Inline ..."" statement. If you really need
991 to specify code to Inline at runtime, you can use the "bind()"
992 method.
993
994 Source code that is stowed in the 'DATA' section of your code, is
995 read in by an "INIT" subroutine in Inline. That's because the
996 "DATA" filehandle is not available at compile time.
997
998 • Check if the Source Code has been Built
999
1000 Inline only needs to build the source code if it has not yet been
1001 built. It accomplishes this seemingly magical task in an extremely
1002 simple and straightforward manner. It runs the source text through
1003 the "Digest::MD5" module to produce a 128-bit "fingerprint" which
1004 is virtually unique. The fingerprint along with a bunch of other
1005 contingency information is stored in a ".inl" file that sits next
1006 to your executable object. For instance, the "C" code from a script
1007 called "example.pl" might create these files:
1008
1009 example_pl_3a9a.so
1010 example_pl_3a9a.inl
1011
1012 If all the contingency information matches the values stored in the
1013 ".inl" file, then proceed to step 8. (No compilation is necessary)
1014
1015 • Find a Place to Build and Install
1016
1017 At this point Inline knows it needs to build the source code. The
1018 first thing to figure out is where to create the great big mess
1019 associated with compilation, and where to put the object when it's
1020 done.
1021
1022 By default Inline will try to build and install under the first
1023 place that meets one of the following conditions:
1024
1025 1. The DIRECTORY= config option; if specified
1026
1027 2. The "PERL_INLINE_DIRECTORY" environment variable; if set
1028
1029 3. ".Inline/" (in current directory); if exists and "$PWD !=
1030 $HOME"
1031
1032 4. bin.Inline (in directory of your script); if exists
1033
1034 5. "~/.Inline/" - if exists
1035
1036 6. "./_Inline/" - if exists
1037
1038 7. "bin/_Inline" - if exists
1039
1040 8. Create "./_Inline/" - if possible
1041
1042 9. Create "bin/_Inline/" - if possible
1043
1044 Failing that, Inline will croak. This is rare and easily remedied
1045 by just making a directory that Inline will use.
1046
1047 If the "PERL_INSTALL_ROOT" Environment Variable has been set, you
1048 will need to make special provision for that if the 'make install'
1049 phase of your Inline scripts are to succeed.
1050
1051 If the module option is being compiled for permanent installation,
1052 then Inline will only use "./_Inline/" to build in, and the
1053 $Config{installsitearch} directory to install the executable in.
1054 This action is caused by Inline::MakeMaker, and is intended to be
1055 used in modules that are to be distributed on the CPAN, so that
1056 they get installed in the proper place.
1057
1058 • Parse the Source for Semantic Cues
1059
1060 Inline::C uses the module "Parse::RecDescent" to parse through your
1061 chunks of C source code and look for things that it can create run-
1062 time bindings to. In "C" it looks for all of the function
1063 definitions and breaks them down into names and data types. These
1064 elements are used to correctly bind the "C" function to a "Perl"
1065 subroutine. Other Inline languages like Python and Java actually
1066 use the "python" and "javac" modules to parse the Inline code.
1067
1068 • Create the Build Environment
1069
1070 Now Inline can take all of the gathered information and create an
1071 environment to build your source code into an executable. Without
1072 going into all the details, it just creates the appropriate
1073 directories, creates the appropriate source files including an XS
1074 file (for C) and a "Makefile.PL".
1075
1076 • Build the Code and Install the Executable
1077
1078 The planets are in alignment. Now for the easy part. Inline just
1079 does what you would do to install a module. "`perl Makefile.PL &&
1080 make && make test && make install>". If something goes awry, Inline
1081 will croak with a message indicating where to look for more info.
1082
1083 • Tidy Up
1084
1085 By default, Inline will remove all of the mess created by the build
1086 process, assuming that everything worked. If the build fails,
1087 Inline will leave everything intact, so that you can debug your
1088 errors. Setting the "noclean" shortcut option will also stop Inline
1089 from cleaning up.
1090
1091 • DynaLoad the Executable
1092
1093 For C (and C++), Inline uses the "DynaLoader::bootstrap" method to
1094 pull your external module into "Perl" space. Now you can call all
1095 of your external functions like Perl subroutines.
1096
1097 Other languages like Python and Java, provide their own loaders.
1098
1100 For information about using Inline with C see Inline::C.
1101
1102 For sample programs using Inline with C see Inline::C-Cookbook.
1103
1104 For "Formerly Answered Questions" about Inline, see Inline-FAQ.
1105
1106 For information on supported languages and platforms see Inline-
1107 Support.
1108
1109 For information on writing your own Inline Language Support Module, see
1110 Inline-API.
1111
1112 Inline's mailing list is inline@perl.org
1113
1114 To subscribe, send email to inline-subscribe@perl.org
1115
1117 When reporting a bug, please do the following:
1118
1119 • Put "use Inline 'reportbug';" at the top of your code, or use the
1120 command line option "perl -MInline=reportbug ...".
1121
1122 • Run your code.
1123
1124 • Follow the printed directions.
1125
1127 Ingy döt Net <ingy@cpan.org>
1128
1129 Sisyphus <sisyphus@cpan.org> fixed some bugs and is current co-
1130 maintainer.
1131
1133 • Copyright 2000-2019. Ingy döt Net.
1134
1135 • Copyright 2008, 2010-2014. Sisyphus.
1136
1137 This program is free software; you can redistribute it and/or modify it
1138 under the same terms as Perl itself.
1139
1140 See <http://www.perl.com/perl/misc/Artistic.html>
1141
1142
1143
1144perl v5.34.0 2021-07-22 Inline(3)