1Inline(3) User Contributed Perl Documentation Inline(3)
2
6 Inline - Write Perl subroutines in other programming languages.
7
9 use Inline C;
10 print "9 + 16 = ", add(9, 16), "\n";
12 print "9 - 16 = ", subtract(9, 16), "\n";
13 __END__
15 __C__
16 int add(int x, int y) {
17 return x + y;
18 }
19 int subtract(int x, int y) {
21 return x - y;
22 }
23
25 The Inline module allows you to put source code from other programming
26 languages directly "inline" in a Perl script or module. The code is
27 automatically compiled as needed, and then loaded for immediate access
28 from Perl.
29 Inline saves you from the hassle of having to write and compile your
31 own glue code using facilities like XS or SWIG. Simply type the code
32 where you want it and run your Perl as normal. All the hairy details
33 are handled for you. The compilation and installation of your code
34 chunks all happen transparently; all you will notice is the delay of
35 compilation on the first run.
36 The Inline code only gets compiled the first time you run it (or
38 whenever it is modified) so you only take the performance hit once.
39 Code that is Inlined into distributed modules (like on the CPAN) will
40 get compiled when the module is installed, so the end user will never
41 notice the compilation time.
42 Best of all, it works the same on both Unix and Microsoft Windows. See
44 Inline-Support for support information.
45 Why Inline?
47 Do you want to know "Why would I use other languages in Perl?" or "Why
48 should I use Inline to do it?"? I'll try to answer both.
49 Why would I use other languages in Perl?
51 The most obvious reason is performance. For an interpreted
52 language, Perl is very fast. Many people will say "Anything Perl
53 can do, C can do faster". (They never mention the development time
54 :-) Anyway, you may be able to remove a bottleneck in your Perl
55 code by using another language, without having to write the entire
56 program in that language. This keeps your overall development time
57 down, because you're using Perl for all of the non-critical code.
58 Another reason is to access functionality from existing API-s that
60 use the language. Some of this code may only be available in binary
61 form. But by creating small subroutines in the native language,
62 you can "glue" existing libraries to your Perl. As a user of the
63 CPAN, you know that code reuse is a good thing. So why throw away
64 those Fortran libraries just yet?
65 If you are using Inline with the C language, then you can access
67 the full internals of Perl itself. This opens up the floodgates to
68 both extreme power and peril.
69 Maybe the best reason is "Because you want to!". Diversity keeps
71 the world interesting. TMTOWTDI!
72 Why should I use Inline to do it?
74 There are already two major facilities for extending Perl with C.
75 They are XS and SWIG. Both are similar in their capabilities, at
76 least as far as Perl is concerned. And both of them are quite
77 difficult to learn compared to Inline.
78 There is a big fat learning curve involved with setting up and
80 using the XS environment. You need to get quite intimate with the
81 following docs:
82 * perlxs
84 * perlxstut
85 * perlapi
86 * perlguts
87 * perlmod
88 * h2xs
89 * xsubpp
90 * ExtUtils::MakeMaker
91 With Inline you can be up and running in minutes. There is a C
93 Cookbook with lots of short but complete programs that you can
94 extend to your real-life problems. No need to learn about the
95 complicated build process going on in the background. You don't
96 even need to compile the code yourself. Inline takes care of every
97 last detail except writing the C code.
98 Perl programmers cannot be bothered with silly things like
100 compiling. "Tweak, Run, Tweak, Run" is our way of life. Inline
101 does all the dirty work for you.
102 Another advantage of Inline is that you can use it directly in a
104 script. You can even use it in a Perl one-liner. With XS and SWIG,
105 you always set up an entirely separate module. Even if you only
106 have one or two functions. Inline makes easy things easy, and hard
107 things possible. Just like Perl.
108 Finally, Inline supports several programming languages (not just C
110 and C++). As of this writing, Inline has support for C, C++, Java,
111 Python, Ruby, Tcl, Assembler, Basic, Guile, Befunge, Octave, Awk,
112 BC, TT (Template Toolkit), WebChat and even PERL. New Inline
113 Language Support Modules (ILSMs) are regularly being added. See
114 Inline-API for details on how to create your own ILSM.
115
117 Inline is a little bit different than most of the Perl modules that you
118 are used to. It doesn't import any functions into your namespace and it
119 doesn't have any object oriented methods. Its entire interface (with
120 two minor exceptions) is specified through the 'use Inline ...'
121 command.
122 This section will explain all of the different ways to "use Inline". If
124 you want to begin using C with Inline immediately, see
125 Inline::C-Cookbook.
126 The Basics
128 The most basic form for using Inline is:
129 use Inline X => "X source code";
131 where 'X' is one of the supported Inline programming languages. The
133 second parameter identifies the source code that you want to bind to
134 Perl. The source code can be specified using any of the following
135 syntaxes:
136 The DATA Keyword.
138 use Inline Java => 'DATA';
139 # Perl code goes here ...
141 __DATA__
143 __Java__
144 /* Java code goes here ... */
145 The easiest and most visually clean way to specify your source code
147 in an Inline Perl program is to use the special "DATA" keyword.
148 This tells Inline to look for a special marker in your "DATA"
149 filehandle's input stream. In this example the special marker is
150 "__Java__", which is the programming language surrounded by double
151 underscores.
152 In case you've forgotten, the "DATA" pseudo file is comprised of
154 all the text after the "__END__" or "__DATA__" section of your
155 program. If you're working outside the "main" package, you'd best
156 use the "__DATA__" marker or else Inline will not find your code.
157 Using this scheme keeps your Perl code at the top, and all the ugly
159 Java stuff down below where it belongs. This is visually clean and
160 makes for more maintainable code. An excellent side benefit is that
161 you don't have to escape any characters like you might in a Perl
162 string. The source code is verbatim. For these reasons, I prefer
163 this method the most.
164 The only problem with this style is that since Perl can't read the
166 "DATA" filehandle until runtime, it obviously can't bind your
167 functions until runtime. The net effect of this is that you can't
168 use your Inline functions as barewords (without predeclaring them)
169 because Perl has no idea they exist during compile time.
170 The FILE and BELOW keywords.
172 use Inline::Files;
173 use Inline Java => 'FILE';
174 # Perl code goes here ...
176 __JAVA__
178 /* Java code goes here ... */
179 This is the newest method of specifying your source code. It makes
181 use of the Perl module "Inline::Files" written by Damian Conway.
182 The basic style and meaning are the same as for the "DATA" keyword,
183 but there are a few syntactic and semantic twists.
184 First, you must say 'use Inline::Files' before you 'use Inline'
186 code that needs those files. The special '"DATA"' keyword is
187 replaced by either '"FILE"' or '"BELOW"'. This allows for the bad
188 pun idiom of:
189 use Inline C => 'BELOW';
191 You can omit the "__DATA__" tag now. Inline::Files is a source
193 filter that will remove these sections from your program before
194 Perl compiles it. They are then available for Inline to make use
195 of. And since this can all be done at compile time, you don't have
196 to worry about the caveats of the 'DATA' keyword.
197 This module has a couple small gotchas. Since Inline::Files only
199 recognizes file markers with capital letters, you must specify the
200 capital form of your language name. Also, there is a startup time
201 penalty for using a source code filter.
202 At this point Inline::Files is alpha software and use of it is
204 experimental. Inline's integration of this module is also fledgling
205 at the time being. One of things I plan to do with Inline::Files is
206 to get line number info so when an extension doesn't compile, the
207 error messages will point to the correct source file and line
208 number.
209 My best advice is to use Inline::Files for testing (especially as
211 support for it improves), but use DATA for production and
212 distributed/CPAN code.
213 Strings
215 use Inline Java => <<'END';
216 /* Java code goes here ... */
218 END
219 # Perl code goes here ...
221 You also just specify the source code as a single string. A handy
223 way to write the string is to use Perl's "here document" style of
224 quoting. This is ok for small functions but can get unwieldy in the
225 large. On the other hand, the string variant probably has the least
226 startup penalty and all functions are bound at compile time.
227 If you wish to put the string into a scalar variable, please be
229 aware that the "use" statement is a compile time directive. As
230 such, all the variables it uses must also be set at compile time,
231 "before" the 'use Inline' statement. Here is one way to do it:
232 my $code;
234 BEGIN {
235 $code = <<END;
236 /* Java code goes here ... */
238 END
239 }
240 use Inline Java => $code;
241 # Perl code goes here ...
243 The bind() Function
245 An alternative to using the BEGIN block method is to specify the
246 source code at run time using the 'Inline->bind()' method. (This is
247 one of the interface exceptions mentioned above) The "bind()"
248 method takes the same arguments as 'use Inline ...'.
249 my $code = <<END;
251 /* Java code goes here ... */
253 END
254 Inline->bind(Java => $code);
256 You can think of "bind()" as a way to "eval()" code in other
258 programming languages.
259 Although bind() is a powerful feature, it is not recommended for
261 use in Inline based modules. In fact, it won't work at all for
262 installable modules. See instructions below for creating modules
263 with Inline.
264 Other Methods
266 The source code for Inline can also be specified as an external
267 filename, a reference to a subroutine that returns source code, or
268 a reference to an array that contains lines of source code. (Note
269 that if the external source file is in the current directory it
270 must be specified with a leading './' - ie './file.ext' instead of
271 simply 'file.ext'.) These methods are less frequently used but may
272 be useful in some situations.
273 Shorthand
275 If you are using the 'DATA' or 'FILE' methods described above and
276 there are no extra parameters, you can omit the keyword altogether.
277 For example:
278 use Inline 'Java';
280 # Perl code goes here ...
282 __DATA__
284 __Java__
285 /* Java code goes here ... */
286 or
288 use Inline::Files;
290 use Inline 'Java';
291 # Perl code goes here ...
293 __JAVA__
295 /* Java code goes here ... */
296 More about the DATA Section
298 If you are writing a module, you can also use the DATA section for POD
299 and AutoLoader subroutines. Just be sure to put them before the first
300 Inline marker. If you install the helper module "Inline::Filters", you
301 can even use POD inside your Inline code. You just have to specify a
302 filter to strip it out.
303 You can also specify multiple Inline sections, possibly in different
305 programming languages. Here is another example:
306 # The module Foo.pm
308 package Foo;
309 use AutoLoader;
310 use Inline C;
312 use Inline C => DATA => FILTERS => 'Strip_POD';
313 use Inline Python;
314 1;
316 __DATA__
318 sub marine {
320 # This is an autoloaded subroutine
321 }
322 =head1 External subroutines
324 =cut
326 __C__
328 /* First C section */
329 __C__
331 /* Second C section */
332 =head1 My C Function
333 Some POD doc.
335 =cut
337 __Python__
339 """A Python Section"""
340 An important thing to remember is that you need to have one "use Inline
342 Foo => 'DATA'" for each "__Foo__" marker, and they must be in the same
343 order. This allows you to apply different configuration options to each
344 section.
345 Configuration Options
347 Inline trys to do the right thing as often as possible. But sometimes
348 you may need to override the default actions. This is easy to do.
349 Simply list the Inline configuration options after the regular Inline
350 parameters. All congiguration options are specified as (key, value)
351 pairs.
352 use Inline (C => 'DATA',
354 DIRECTORY => './inline_dir',
355 LIBS => '-lfoo',
356 INC => '-I/foo/include',
357 PREFIX => 'XXX_',
358 WARNINGS => 0,
359 );
360 You can also specify the configuration options on a separate Inline
362 call like this:
363 use Inline (C => Config =>
365 DIRECTORY => './inline_dir',
366 LIBS => '-lfoo',
367 INC => '-I/foo/include',
368 PREFIX => 'XXX_',
369 WARNINGS => 0,
370 );
371 use Inline C => <<'END_OF_C_CODE';
372 The special keyword 'Config' tells Inline that this is a configuration-
374 only call. No source code will be compiled or bound to Perl.
375 If you want to specify global configuration options that don't apply to
377 a particular language, just leave the language out of the call. Like
378 this:
379 use Inline Config => WARNINGS => 0;
381 The Config options are inherited and additive. You can use as many
383 Config calls as you want. And you can apply different options to
384 different code sections. When a source code section is passed in,
385 Inline will apply whichever options have been specified up to that
386 point. Here is a complex configuration example:
387 use Inline (Config =>
389 DIRECTORY => './inline_dir',
390 );
391 use Inline (C => Config =>
392 LIBS => '-lglobal',
393 );
394 use Inline (C => 'DATA', # First C Section
395 LIBS => ['-llocal1', '-llocal2'],
396 );
397 use Inline (Config =>
398 WARNINGS => 0,
399 );
400 use Inline (Python => 'DATA', # First Python Section
401 LIBS => '-lmypython1',
402 );
403 use Inline (C => 'DATA', # Second C Section
404 LIBS => [undef, '-llocal3'],
405 );
406 The first "Config" applies to all subsequent calls. The second "Config"
408 applies to all subsequent "C" sections (but not "Python" sections). In
409 the first "C" section, the external libraries "global", "local1" and
410 "local2" are used. (Most options allow either string or array ref
411 forms, and do the right thing.) The "Python" section does not use the
412 "global" library, but does use the same "DIRECTORY", and has warnings
413 turned off. The second "C" section only uses the "local3" library.
414 That's because a value of "undef" resets the additive behavior.
415 The "DIRECTORY" and "WARNINGS" options are generic Inline options. All
417 other options are language specific. To find out what the "C" options
418 do, see "Inline::C".
419 On and Off
421 If a particular config option has value options of 1 and 0, you can use
422 the ENABLE and DISABLE modifiers. In other words, this:
423 use Inline Config =>
425 FORCE_BUILD => 1,
426 CLEAN_AFTER_BUILD => 0;
427 could be reworded as:
429 use Inline Config =>
431 ENABLE => FORCE_BUILD,
432 DISABLE => CLEAN_AFTER_BUILD;
433 Playing 'with' Others
435 Inline has a special configuration syntax that tells it to get more
436 configuration options from other Perl modules. Here is an example:
437 use Inline with => 'Event';
439 This tells Inline to load the module "Event.pm" and ask it for
441 configuration information. Since "Event" has a C API of its own, it can
442 pass Inline all of the information it needs to be able to use "Event" C
443 callbacks seamlessly.
444 That means that you don't need to specify the typemaps, shared
446 libraries, include files and other information required to get this to
447 work.
448 You can specify a single module or a list of them. Like:
450 use Inline with => qw(Event Foo Bar);
452 Currently, "Event" is the only module that works with Inline.
454 Inline Shortcuts
456 Inline lets you set many configuration options from the command line.
457 These options are called 'shortcuts'. They can be very handy,
458 especially when you only want to set the options temporarily, for say,
459 debugging.
460 For instance, to get some general information about your Inline code in
462 the script "Foo.pl", use the command:
463 perl -MInline=INFO Foo.pl
465 If you want to force your code to compile, even if its already done,
467 use:
468 perl -MInline=FORCE Foo.pl
470 If you want to do both, use:
472 perl -MInline=INFO -MInline=FORCE Foo.pl
474 or better yet:
476 perl -MInline=INFO,FORCE Foo.pl
478 The Inline DIRECTORY
480 Inline needs a place to build your code and to install the results of
481 the build. It uses a single directory named '.Inline/' under normal
482 circumstances. If you create this directory in your home directory, the
483 current directory or in the directory where your program resides,
484 Inline will find and use it. You can also specify it in the environment
485 variable "PERL_INLINE_DIRECTORY" or directly in your program, by using
486 the "DIRECTORY" keyword option. If Inline cannot find the directory in
487 any of these places it will create a '_Inline/' directory in either
488 your current directory or the directory where your script resides.
489 One of the key factors to using Inline successfully, is understanding
491 this directory. When developing code it is usually best to create this
492 directory (or let Inline do it) in your current directory. Remember
493 that there is nothing sacred about this directory except that it holds
494 your compiled code. Feel free to delete it at any time. Inline will
495 simply start from scratch and recompile your code on the next run. If
496 you have several programs that you want to force to recompile, just
497 delete your '.Inline/' directory.
498 It is probably best to have a separate '.Inline/' directory for each
500 project that you are working on. You may want to keep stable code in
501 the <.Inline/> in your home directory. On multi-user systems, each user
502 should have their own '.Inline/' directories. It could be a security
503 risk to put the directory in a shared place like "/tmp/".
504 Debugging Inline Errors
506 All programmers make mistakes. When you make a mistake with Inline,
507 like writing bad C code, you'll get a big error report on your screen.
508 This report tells you where to look to do the debugging. Some languages
509 may also dump out the error messages generated from the build.
510 When Inline needs to build something it creates a subdirectory under
512 your "DIRECTORY/build/" directory. This is where it writes all the
513 components it needs to build your extension. Things like XS files,
514 Makefiles and output log files.
515 If everything goes OK, Inline will delete this subdirectory. If there
517 is an error, Inline will leave the directory intact and print its
518 location. The idea is that you are supposed to go into that directory
519 and figure out what happened.
520 Read the doc for your particular Inline Language Support Module for
522 more information.
523 The 'config' Registry File
525 Inline keeps a cached file of all of the Inline Language Support
526 Module's meta data in a file called "config". This file can be found in
527 your "DIRECTORY" directory. If the file does not exist, Inline creates
528 a new one. It will search your system for any module beginning with
529 "Inline::". It will then call that module's "register()" method to get
530 useful information for future invocations.
531 Whenever you add a new ILSM, you should delete this file so that Inline
533 will auto-discover your newly installed language module. (This should
534 no longer be necessary as of Inline-0.49.)
535
537 This section lists all of the generic Inline configuration options. For
538 language specific configuration, see the doc for that language.
539 DIRECTORY
541 The "DIRECTORY" config option is the directory that Inline uses to both
542 build and install an extension.
543 Normally Inline will search in a bunch of known places for a directory
545 called '.Inline/'. Failing that, it will create a directory called
546 '_Inline/'
547 If you want to specify your own directory, use this configuration
549 option.
550 Note that you must create the "DIRECTORY" directory yourself. Inline
552 will not do it for you.
553 NAME
555 You can use this option to set the name of your Inline extension object
556 module. For example:
557 use Inline C => 'DATA',
559 NAME => 'Foo::Bar';
560 would cause your C code to be compiled in to the object:
562 lib/auto/Foo/Bar/Bar.so
564 lib/auto/Foo/Bar/Bar.inl
565 (The .inl component contains dependency information to make sure the
567 source code is in sync with the executable)
568 If you don't use NAME, Inline will pick a name for you based on your
570 program name or package name. In this case, Inline will also enable the
571 AUTONAME option which mangles in a small piece of the MD5 fingerprint
572 into your object name, to make it unique.
573 AUTONAME
575 This option is enabled whenever the NAME parameter is not specified. To
576 disable it say:
577 use Inline C => 'DATA',
579 DISABLE => 'AUTONAME';
580 AUTONAME mangles in enough of the MD5 fingerprint to make your module
582 name unique. Objects created with AUTONAME will never get replaced.
583 That also means they will never get cleaned up automatically.
584 AUTONAME is very useful for small throw away scripts. For more serious
586 things, always use the NAME option.
587 VERSION
589 Specifies the version number of the Inline extension object. It is used
590 only for modules, and it must match the global variable $VERSION.
591 Additionally, this option should used if (and only if) a module is
592 being set up to be installed permanently into the Perl sitelib tree.
593 Inline will croak if you use it otherwise.
594 The presence of the VERSION parameter is the official way to let Inline
596 know that your code is an installable/installed module. Inline will
597 never generate an object in the temporary cache (_Inline/ directory) if
598 VERSION is set. It will also never try to recompile a module that was
599 installed into someone's Perl site tree.
600 So the basic rule is develop without VERSION, and deliver with VERSION.
602 WITH
604 "WITH" can also be used as a configuration option instead of using the
605 special 'with' syntax. Do this if you want to use different sections of
606 Inline code with different modules. (Probably a very rare usage)
607 use Event;
609 use Inline C => DATA => WITH => 'Event';
610 Modules specified using the config form of "WITH" will not be
612 automatically required. You must "use" them yourself.
613 GLOBAL_LOAD
615 This option is for compiled languages only. It tells Inline to tell
616 DynaLoader to load an object file in such a way that its symbols can be
617 dynamically resolved by other object files. May not work on all
618 platforms. See the "GLOBAL" shortcut below.
619 UNTAINT
621 You can use this option whenever you use Perl's "-T" switch, for taint
622 checking. This option tells Inline to blindly untaint all tainted
623 variables. (This is generally considerd to be an appallingly insecure
624 thing to do, and not to be recommended - but the option is there for
625 you to use if you want. Please consider using something other than
626 Inline for scripts that need taint checking.) It also turns on
627 SAFEMODE by default. See the "UNTAINT" shortcut below. You will see
628 warnings about blindly untainting fields in both %ENV and Inline
629 objects. If you want to silence these warnings, set the Config option
630 NO_UNTAINT_WARN => 1. There can be some problems untainting Inline
631 scripts where older versions of Cwd, such as those that shipped with
632 early versions of perl-5.8 (and earlier), are installed. Updating Cwd
633 will probably solve these problems.
634 SAFEMODE
636 Perform extra safety checking, in an attempt to thwart malicious code.
637 This option cannot guarantee security, but it does turn on all the
638 currently implemented checks. (Currently, the only "currently
639 implemented check" is to ensure that the "DIRECTORY" option has also
640 been used.)
641 There is a slight startup penalty by using SAFEMODE. Also, using
643 UNTAINT automatically turns this option on. If you need your code to
644 start faster under "-T" (taint) checking, you'll need to turn this
645 option off manually. Only do this if you are not worried about security
646 risks. See the "UNSAFE" shortcut below.
647 FORCE_BUILD
649 Makes Inline build (compile) the source code every time the program is
650 run. The default is 0. See the "FORCE" shortcut below.
651 BUILD_NOISY
653 Tells ILSMs that they should dump build messages to the terminal rather
654 than be silent about all the build details.
655 BUILD_TIMERS
657 Tells ILSMs to print timing information about how long each build phase
658 took. Usually requires "Time::HiRes".
659 CLEAN_AFTER_BUILD
661 Tells Inline to clean up the current build area if the build was
662 successful. Sometimes you want to DISABLE this for debugging. Default
663 is 1. See the "NOCLEAN" shortcut below.
664 CLEAN_BUILD_AREA
666 Tells Inline to clean up the old build areas within the entire Inline
667 DIRECTORY. Default is 0. See the "CLEAN" shortcut below.
668 PRINT_INFO
670 Tells Inline to print various information about the source code.
671 Default is 0. See the "INFO" shortcut below.
672 PRINT_VERSION
674 Tells Inline to print Version info about itself. Default is 0. See the
675 "VERSION" shortcut below.
676 REPORTBUG
678 Puts Inline into 'REPORTBUG' mode, which is what you want if you desire
679 to report a bug.
680 REWRITE_CONFIG_FILE
682 Default is 0, but setting 'REWRITE_CONFIG_FILE => 1' will mean that the
683 existing configuration file in the Inline DIRECTORY will be
684 overwritten. (This is useful if the existing config file is not up to
685 date as regards supported languages.)
686 WARNINGS
688 This option tells Inline whether to print certain warnings. Default is
689 1.
690
692 This is a list of all the shorcut configuration options currently
693 available for Inline. Specify them from the command line when running
694 Inline scripts.
695 perl -MInline=NOCLEAN inline_script.pl
697 or
699 perl -MInline=Info,force,NoClean inline_script.pl
701 You can specify multiple shortcuts separated by commas. They are not
703 case sensitive. You can also specify shorcuts inside the Inline program
704 like this:
705 use Inline 'Info', 'Force', 'Noclean';
707 NOTE: If a 'use Inline' statement is used to set shortcuts, it can not
709 be used for additional purposes.
710 CLEAN
712 Tells Inline to remove any build directories that may be lying
713 around in your build area. Normally these directories get removed
714 immediately after a successful build. Exceptions are when the build
715 fails, or when you use the NOCLEAN or REPORTBUG options.
716 FORCE
718 Forces the code to be recompiled, even if everything is up to date.
719 GLOBAL
721 Turns on the GLOBAL_LOAD option.
722 INFO
724 This is a very useful option when you want to know what's going on
725 under the hood. It tells Inline to print helpful information to
726 "STDERR". Among the things that get printed is a list of which
727 Inline functions were successfully bound to Perl.
728 NOCLEAN
730 Tells Inline to leave the build files after compiling.
731 NOISY
733 Use the BUILD_NOISY option to print messages during a build.
734 REPORTBUG
736 Puts Inline into 'REPORTBUG' mode, which does special processing
737 when you want to report a bug. REPORTBUG also automatically forces
738 a build, and doesn't clean up afterwards. This is so that you can
739 tar and mail the build directory to me. REPORTBUG will print exact
740 instructions on what to do. Please read and follow them carefully.
741 NOTE: REPORTBUG informs you to use the tar command. If your system
743 does not have tar, please use the equivalent "zip" command.
744 SAFE
746 Turns SAFEMODE on. UNTAINT will turn this on automatically. While
747 this mode performs extra security checking, it does not guarantee
748 safety.
749 SITE_INSTALL
751 This parameter used to be used for creating installable Inline
752 modules. It has been removed from Inline altogether and replaced
753 with a much simpler and more powerful mechanism,
754 "Inline::MakeMaker". See the section below on how to create modules
755 with Inline.
756 _TESTING
758 Used internally by C/t/09parser.t and C/t/10callback.t(in the
759 Inline::C test suite). Setting this option with Inline::C will mean
760 that files named 'parser_id' and 'void_test' are created in the
761 ./Inline_test directory, creating that directory if it doesn't
762 already exist. The files (but not the ./Inline_test directory) are
763 cleaned up by calling Inline::C::_testing_cleanup(). Also used by
764 t/06rewrite_config.t to trigger a warning.
765 TIMERS
767 Turn on BUILD_TIMERS to get extra diagnostic info about builds.
768 UNSAFE
770 Turns SAFEMODE off. Use this in combination with UNTAINT for
771 slightly faster startup time under "-T". Only use this if you are
772 sure the environment is safe.
773 UNTAINT
775 Turn the UNTAINT option on. Used with "-T" switch. In terms of
776 secure practices, this is definitely *not* a recommended way of
777 dealing with taint checking, but it's the *only* option currently
778 available with Inline. Use it at your own risk.
779 VERSION
781 Tells Inline to report its release version.
782
784 Writing CPAN modules that use C code is easy with Inline. Let's say
785 that you wanted to write a module called "Math::Simple". Start by using
786 the following command:
787 h2xs -PAXn Math::Simple
789 This will generate a bunch of files that form a skeleton of what you
791 need for a distributable module. (Read the h2xs manpage to find out
792 what the options do) Next, modify the "Simple.pm" file to look like
793 this:
794 package Math::Simple;
796 $VERSION = '1.23';
797 use base 'Exporter';
799 @EXPORT_OK = qw(add subtract);
800 use strict;
801 use Inline C => 'DATA',
803 VERSION => '1.23',
804 NAME => 'Math::Simple';
805 # The following Inline->init() call is optional - see below for more info.
807 #Inline->init();
808 1;
810 __DATA__
812 =pod
814 =cut
816 __C__
818 int add(int x, int y) {
819 return x + y;
820 }
821 int subtract(int x, int y) {
823 return x - y;
824 }
825 The important things to note here are that you must specify a "NAME"
827 and "VERSION" parameter. The "NAME" must match your module's package
828 name. The "VERSION" parameter must match your module's $VERSION
829 variable and they must be of the form "/^\d\.\d\d$/".
830 NOTE: These are Inline's sanity checks to make sure you know what
832 you're doing before uploading your code to CPAN. They insure that once
833 the module has been installed on someone's system, the module would not
834 get automatically recompiled for any reason. This makes Inline based
835 modules work in exactly the same manner as XS based ones.
836 Finally, you need to modify the Makefile.PL. Simply change:
838 use ExtUtils::MakeMaker;
840 to
842 use Inline::MakeMaker;
844 And, in order that the module build work correctly in the cpan shell,
846 add the following directive to the Makefile.PL's WriteMakefile():
847 CONFIGURE_REQUIRES => {
849 'Inline::MakeMaker' => 0.45,
850 'ExtUtils::MakeMaker' => 6.52,
851 },
852 This "CONFIGURE_REQUIRES" directive ensures that the cpan shell will
854 install Inline on the user's machine (if it's not already present)
855 before building your Inline-based module. Specifying of
856 "ExtUtils::MakeMaker => 6.52," is optional, and can be omitted if you
857 like. It ensures only that some harmless warnings relating to the
858 "CONFIGURE_REQUIRES" directive won't be emitted during the building of
859 the module. It also means, of course, that ExtUtils::Makemaker will
860 first be updated on the user's machine unless the user already has
861 version 6.52 or later.
862 If the "Inline->init();" is not done then, having installed
864 Math::Simple, a warning that "One or more DATA sections were not
865 processed by Inline" will appear when (and only when) Math::Simple is
866 loaded by a "require call. It's a harmless warning - and if you're
867 prepared to live with it, then there's no need to make the
868 "Inline->init();" call.
869 When the person installing "Math::Simple" does a ""make"", the
871 generated Makefile will invoke Inline in such a way that the C code
872 will be compiled and the executable code will be placed into the
873 "./blib" directory. Then when a ""make install"" is done, the module
874 will be copied into the appropriate Perl sitelib directory (which is
875 where an installed module should go).
876 Now all you need to do is:
878 perl Makefile.PL
880 make dist
881 That will generate the file "Math-Simple-0.20.tar.gz" which is a
883 distributable package. (It will also generate some harmless warnings in
884 relation to "CONFIGURE_REQUIRES" unless the version of your
885 ExtUtils::MakeMaker is 6.52 or later.) That's all there is to it.
886 IMPORTANT NOTE: Although the above steps will produce a workable
888 module, you still have a few more responsibilities as a budding new
889 CPAN author. You need to write lots of documentation and write lots of
890 tests. Take a look at some of the better CPAN modules for ideas on
891 creating a killer test harness. Actually, don't listen to me, go read
892 these:
893 perldoc perlnewmod
895 http://www.cpan.org/modules/04pause.html
896 http://www.cpan.org/modules/00modlist.long.html
897
899 In reality, Inline just automates everything you would need to do if
900 you were going to do it by hand (using XS, etc).
901 Inline performs the following steps:
903 1) Receive the Source Code
905 Inline gets the source code from your script or module with a
906 statements like the following:
907 use Inline C => "Source-Code";
909 or
911 use Inline;
913 bind Inline C => "Source-Code";
914 where "C" is the programming language of the source code, and
916 "Source-Code" is a string, a file name, an array reference, or the
917 special 'DATA' keyword.
918 Since Inline is coded in a ""use"" statement, everything is done
920 during Perl's compile time. If anything needs to be done that will
921 affect the "Source-Code", it needs to be done in a "BEGIN" block
922 that is before the ""use Inline ..."" statement. If you really need
923 to specify code to Inline at runtime, you can use the "bind()"
924 method.
925 Source code that is stowed in the 'DATA' section of your code, is
927 read in by an "INIT" subroutine in Inline. That's because the
928 "DATA" filehandle is not available at compile time.
929 2) Check if the Source Code has been Built
931 Inline only needs to build the source code if it has not yet been
932 built. It accomplishes this seemingly magical task in an extremely
933 simple and straightforward manner. It runs the source text through
934 the "Digest::MD5" module to produce a 128-bit "fingerprint" which
935 is virtually unique. The fingerprint along with a bunch of other
936 contingency information is stored in a ".inl" file that sits next
937 to your executable object. For instance, the "C" code from a script
938 called "example.pl" might create these files:
939 example_pl_3a9a.so
941 example_pl_3a9a.inl
942 If all the contingency information matches the values stored in the
944 ".inl" file, then proceed to step 8. (No compilation is necessary)
945 3) Find a Place to Build and Install
947 At this point Inline knows it needs to build the source code. The
948 first thing to figure out is where to create the great big mess
949 associated with compilation, and where to put the object when it's
950 done.
951 By default Inline will try to build and install under the first
953 place that meets one of the following conditions:
954 A) The DIRECTORY= config option; if specified
956 B) The PERL_INLINE_DIRECTORY environment variable; if set
957 C) .Inline/ (in current directory); if exists and $PWD != $HOME
958 D) bin/.Inline/ (in directory of your script); if exists
959 E) ~/.Inline/; if exists
960 F) ./_Inline/; if exists
961 G) bin/_Inline; if exists
962 H) Create ./_Inline/; if possible
963 I) Create bin/_Inline/; if possible
964 Failing that, Inline will croak. This is rare and easily remedied
966 by just making a directory that Inline will use.
967 If the PERL_INSTALL_ROOT Environment Variable has been set, you
969 will need to make special provision for that if the 'make install'
970 phase of your Inline scripts are to succeed.
971 If the module option is being compiled for permanent installation,
973 then Inline will only use "./_Inline/" to build in, and the
974 $Config{installsitearch} directory to install the executable in.
975 This action is caused by Inline::MakeMaker, and is intended to be
976 used in modules that are to be distributed on the CPAN, so that
977 they get installed in the proper place.
978 4) Parse the Source for Semantic Cues
980 Inline::C uses the module "Parse::RecDescent" to parse through your
981 chunks of C source code and look for things that it can create run-
982 time bindings to. In "C" it looks for all of the function
983 definitions and breaks them down into names and data types. These
984 elements are used to correctly bind the "C" function to a "Perl"
985 subroutine. Other Inline languages like Python and Java actually
986 use the "python" and "javac" modules to parse the Inline code.
987 5) Create the Build Environment
989 Now Inline can take all of the gathered information and create an
990 environment to build your source code into an executable. Without
991 going into all the details, it just creates the appropriate
992 directories, creates the appropriate source files including an XS
993 file (for C) and a "Makefile.PL".
994 6) Build the Code and Install the Executable
996 The planets are in alignment. Now for the easy part. Inline just
997 does what you would do to install a module. ""perl Makefile.PL &&
998 make && make test && make install"". If something goes awry, Inline
999 will croak with a message indicating where to look for more info.
1000 7) Tidy Up
1002 By default, Inline will remove all of the mess created by the build
1003 process, assuming that everything worked. If the build fails,
1004 Inline will leave everything intact, so that you can debug your
1005 errors. Setting the "NOCLEAN" shortcut option will also stop Inline
1006 from cleaning up.
1007 8) DynaLoad the Executable
1009 For C (and C++), Inline uses the "DynaLoader::bootstrap" method to
1010 pull your external module into "Perl" space. Now you can call all
1011 of your external functions like Perl subroutines.
1012 Other languages like Python and Java, provide their own loaders.
1014
1016 For information about using Inline with C see Inline::C.
1017 For sample programs using Inline with C see Inline::C-Cookbook.
1019 For "Formerly Answered Questions" about Inline, see Inline-FAQ.
1021 For information on supported languages and platforms see Inline-
1023 Support.
1024 For information on writing your own Inline Language Support Module, see
1026 Inline-API.
1027 Inline's mailing list is inline@perl.org
1029 To subscribe, send email to inline-subscribe@perl.org
1031
1033 When reporting a bug, please do the following:
1034 - Put "use Inline REPORTBUG;" at the top of your code, or
1036 use the command line option "perl -MInline=REPORTBUG ...".
1037 - Run your code.
1038 - Follow the printed directions.
1039
1041 Brian Ingerson <INGY@cpan.org>
1042 Neil Watkiss <NEILW@cpan.org> is the author of "Inline::CPP",
1044 "Inline::Python", "Inline::Ruby", "Inline::ASM", "Inline::Struct" and
1045 "Inline::Filters". He is known in the innermost Inline circles as the
1046 "Boy Wonder".
1047 Sisyphus <sisyphus@cpan.org> fixed some bugs and is current co-
1049 maintainer.
1050
1052 Copyright (c) 2000-2002. Brian Ingerson.
1053 Copyright (c) 2008, 2010-2013. Sisyphus.
1055 This program is free software; you can redistribute it and/or modify it
1057 under the same terms as Perl itself.
1058 See http://www.perl.com/perl/misc/Artistic.html
1060perl v5.16.3 2013-04-10 Inline(3)