Commit | Line | Data |
f102b883 |
1 | =head1 NAME |
2 | |
3 | perlmodlib - constructing new Perl modules and finding existing ones |
4 | |
5 | =head1 DESCRIPTION |
6 | |
7 | =head1 THE PERL MODULE LIBRARY |
8 | |
19799a22 |
9 | Many modules are included the Perl distribution. These are described |
10 | below, and all end in F<.pm>. You may discover compiled library |
11 | file (usually ending in F<.so>) or small pieces of modules to be |
12 | autoloaded (ending in F<.al>); these were automatically generated |
13 | by the installation process. You may also discover files in the |
14 | library directory that end in either F<.pl> or F<.ph>. These are |
15 | old libraries supplied so that old programs that use them still |
16 | run. The F<.pl> files will all eventually be converted into standard |
17 | modules, and the F<.ph> files made by B<h2ph> will probably end up |
18 | as extension modules made by B<h2xs>. (Some F<.ph> values may |
19 | already be available through the POSIX, Errno, or Fcntl modules.) |
20 | The B<pl2pm> file in the distribution may help in your conversion, |
21 | but it's just a mechanical process and therefore far from bulletproof. |
f102b883 |
22 | |
23 | =head2 Pragmatic Modules |
24 | |
19799a22 |
25 | They work somewhat like compiler directives (pragmata) in that they |
26 | tend to affect the compilation of your program, and thus will usually |
27 | work well only when used within a C<use>, or C<no>. Most of these |
28 | are lexically scoped, so an inner BLOCK may countermand them |
29 | by saying: |
f102b883 |
30 | |
31 | no integer; |
32 | no strict 'refs'; |
33 | |
34 | which lasts until the end of that BLOCK. |
35 | |
19799a22 |
36 | Some pragmas are lexically scoped--typically those that affect the |
37 | C<$^H> hints variable. Others affect the current package instead, |
38 | like C<use vars> and C<use subs>, whic allow you to predeclare a |
39 | variables or subroutines within a particular I<file> rather than |
40 | just a block. Such declarations are effective for the entire file |
41 | for which they were declared. You cannot rescind them with C<no |
42 | vars> or C<no subs>. |
f102b883 |
43 | |
44 | The following pragmas are defined (and have their own documentation). |
45 | |
46 | =over 12 |
47 | |
19799a22 |
48 | =item attrs |
f102b883 |
49 | |
19799a22 |
50 | set/get attributes of a subroutine |
51 | |
52 | =item autouse |
53 | |
54 | postpone load of modules until a function is used |
55 | |
56 | =item base |
57 | |
58 | Establish IS-A relationship with base class at compile time |
f102b883 |
59 | |
60 | =item blib |
61 | |
19799a22 |
62 | Use MakeMaker's uninstalled version of a package |
63 | |
64 | =item constant |
65 | |
66 | declare constants |
f102b883 |
67 | |
68 | =item diagnostics |
69 | |
19799a22 |
70 | Perl compiler pragma to force verbose warning diagnostics |
71 | |
72 | =item fields |
73 | |
74 | compile-time class fields |
75 | |
76 | =item filetest |
77 | |
78 | control the filetest permission operators |
f102b883 |
79 | |
80 | =item integer |
81 | |
82 | compute arithmetic in integer instead of double |
83 | |
84 | =item less |
85 | |
19799a22 |
86 | perl pragma to request less of something from the compiler |
f102b883 |
87 | |
88 | =item lib |
89 | |
90 | manipulate @INC at compile time |
91 | |
92 | =item locale |
93 | |
19799a22 |
94 | use and avoid POSIX locales for built-in operations |
f102b883 |
95 | |
96 | =item ops |
97 | |
19799a22 |
98 | restrict unsafe operations when compiling |
f102b883 |
99 | |
100 | =item overload |
101 | |
19799a22 |
102 | Package for overloading perl operations |
f102b883 |
103 | |
b3eb6a9b |
104 | =item re |
105 | |
19799a22 |
106 | alter regular expression behavior |
b3eb6a9b |
107 | |
f102b883 |
108 | =item sigtrap |
109 | |
110 | enable simple signal handling |
111 | |
112 | =item strict |
113 | |
114 | restrict unsafe constructs |
115 | |
116 | =item subs |
117 | |
118 | predeclare sub names |
119 | |
19799a22 |
120 | =item utf8 |
f102b883 |
121 | |
19799a22 |
122 | turn on UTF-8 and Unicode support |
f102b883 |
123 | |
124 | =item vars |
125 | |
126 | predeclare global variable names |
127 | |
19799a22 |
128 | =item vmsish |
129 | |
130 | control VMS-specific language features |
131 | |
132 | =item warning |
133 | |
134 | control optional warnings |
135 | |
f102b883 |
136 | =back |
137 | |
138 | =head2 Standard Modules |
139 | |
140 | Standard, bundled modules are all expected to behave in a well-defined |
141 | manner with respect to namespace pollution because they use the |
142 | Exporter module. See their own documentation for details. |
143 | |
144 | =over 12 |
145 | |
146 | =item AnyDBM_File |
147 | |
148 | provide framework for multiple DBMs |
149 | |
150 | =item AutoLoader |
151 | |
19799a22 |
152 | load subroutines only on demand |
f102b883 |
153 | |
154 | =item AutoSplit |
155 | |
156 | split a package for autoloading |
157 | |
19799a22 |
158 | =item B |
159 | |
160 | The Perl Compiler; See also L<perlcc>. |
161 | |
162 | =item B::Asmdata |
163 | |
164 | Autogenerated data about Perl ops, used to generate bytecode |
165 | |
166 | =item B::Assembler |
167 | |
168 | Assemble Perl bytecode |
169 | |
170 | =item B::Bblock |
171 | |
172 | Walk basic blocks |
173 | |
174 | =item B::Bytecode |
175 | |
176 | Perl compiler's bytecode backend |
177 | |
178 | =item B::C |
179 | |
180 | Perl compiler's C backend |
181 | |
182 | =item B::CC |
183 | |
184 | Perl compiler's optimized C translation backend |
185 | |
186 | =item B::Debug |
187 | |
188 | Walk Perl syntax tree, printing debug info about ops |
189 | |
190 | =item B::Deparse |
191 | |
192 | Perl compiler backend to produce perl code |
193 | |
194 | =item B::Disassembler |
195 | |
196 | Disassemble Perl bytecode |
197 | |
198 | =item B::Lint |
199 | |
200 | Perl lint |
201 | |
202 | =item B::Showlex |
203 | |
204 | Show lexical variables used in functions or files |
205 | |
206 | =item B::Stackobj |
207 | |
208 | Helper module for CC backend |
209 | |
210 | =item B::Terse |
211 | |
212 | Walk Perl syntax tree, printing terse info about ops |
213 | |
214 | =item B::Xref |
215 | |
216 | Generates cross reference reports for Perl programs |
217 | |
f102b883 |
218 | =item Benchmark |
219 | |
220 | benchmark running times of code |
221 | |
19799a22 |
222 | =item CGI |
223 | |
224 | Simple Common Gateway Interface Class |
225 | |
226 | =item CGI::Apache |
227 | |
228 | Make things work with CGI.pm against Perl-Apache API |
229 | |
230 | =item CGI::Carp |
231 | |
232 | CGI routines for writing to the HTTPD (or other) error log |
233 | |
234 | =item CGI::Cookie |
235 | |
236 | Interface to Netscape Cookies |
237 | |
238 | =item CGI::Fast |
239 | |
240 | CGI Interface for Fast CGI |
241 | |
242 | =item CGI::Push |
243 | |
244 | Simple Interface to Server Push |
245 | |
246 | =item CGI::Switch |
247 | |
248 | Try more than one constructors and return the first object available |
249 | |
f102b883 |
250 | =item CPAN |
251 | |
19799a22 |
252 | query, download and build perl modules from CPAN sites |
f102b883 |
253 | |
254 | =item CPAN::FirstTime |
255 | |
19799a22 |
256 | Utility for CPAN::Config file Initialization |
f102b883 |
257 | |
258 | =item CPAN::Nox |
259 | |
19799a22 |
260 | Wrapper around CPAN.pm without using any XS module |
f102b883 |
261 | |
262 | =item Carp |
263 | |
264 | warn of errors (from perspective of caller) |
265 | |
266 | =item Class::Struct |
267 | |
19799a22 |
268 | declare struct-like datatypes as Perl classes |
f102b883 |
269 | |
270 | =item Config |
271 | |
272 | access Perl configuration information |
273 | |
274 | =item Cwd |
275 | |
276 | get pathname of current working directory |
277 | |
19799a22 |
278 | =item DB |
279 | |
280 | programmatic interface to the Perl debugging API |
281 | |
f102b883 |
282 | =item DB_File |
283 | |
19799a22 |
284 | Perl5 access to Berkeley DB version 1.x |
285 | |
286 | =item Data::Dumper |
287 | |
288 | stringified perl data structures, suitable for both printing and C<eval> |
f102b883 |
289 | |
f505c983 |
290 | =item Devel::Peek |
291 | |
19799a22 |
292 | A data debugging tool for the XS programmer |
f505c983 |
293 | |
f102b883 |
294 | =item Devel::SelfStubber |
295 | |
296 | generate stubs for a SelfLoading module |
297 | |
298 | =item DirHandle |
299 | |
300 | supply object methods for directory handles |
301 | |
19799a22 |
302 | =item Dumpvalue |
303 | |
304 | provides screen dump of Perl data. |
305 | |
f102b883 |
306 | =item DynaLoader |
307 | |
19799a22 |
308 | Dynamically load C libraries into Perl code |
f102b883 |
309 | |
310 | =item English |
311 | |
312 | use nice English (or awk) names for ugly punctuation variables |
313 | |
314 | =item Env |
315 | |
19799a22 |
316 | perl module that imports environment variables |
317 | |
318 | =item Errno |
319 | |
320 | System errno constants |
f102b883 |
321 | |
322 | =item Exporter |
323 | |
19799a22 |
324 | Implements default import method for modules |
325 | |
326 | =item ExtUtils::Command |
327 | |
328 | utilities to replace common UNIX commands in Makefiles etc. |
f102b883 |
329 | |
330 | =item ExtUtils::Embed |
331 | |
19799a22 |
332 | Utilities for embedding Perl in C/C++ applications |
f102b883 |
333 | |
334 | =item ExtUtils::Install |
335 | |
336 | install files from here to there |
337 | |
19799a22 |
338 | =item ExtUtils::Installed |
339 | |
340 | Inventory management of installed modules |
341 | |
f102b883 |
342 | =item ExtUtils::Liblist |
343 | |
344 | determine libraries to use and how to use them |
345 | |
346 | =item ExtUtils::MM_OS2 |
347 | |
19799a22 |
348 | methods to override UN*X behavior in ExtUtils::MakeMaker |
f102b883 |
349 | |
350 | =item ExtUtils::MM_Unix |
351 | |
352 | methods used by ExtUtils::MakeMaker |
353 | |
354 | =item ExtUtils::MM_VMS |
355 | |
19799a22 |
356 | methods to override UN*X behavior in ExtUtils::MakeMaker |
357 | |
358 | =item ExtUtils::MM_Win32 |
359 | |
360 | methods to override UN*X behavior in ExtUtils::MakeMaker |
f102b883 |
361 | |
362 | =item ExtUtils::MakeMaker |
363 | |
364 | create an extension Makefile |
365 | |
366 | =item ExtUtils::Manifest |
367 | |
368 | utilities to write and check a MANIFEST file |
369 | |
19799a22 |
370 | =item ExtUtils::Miniperl |
371 | |
372 | write the C code for perlmain.c |
373 | |
f102b883 |
374 | =item ExtUtils::Mkbootstrap |
375 | |
376 | make a bootstrap file for use by DynaLoader |
377 | |
378 | =item ExtUtils::Mksymlists |
379 | |
380 | write linker options files for dynamic extension |
381 | |
19799a22 |
382 | =item ExtUtils::Packlist |
383 | |
384 | manage .packlist files |
385 | |
f102b883 |
386 | =item ExtUtils::testlib |
387 | |
388 | add blib/* directories to @INC |
389 | |
b6c543e3 |
390 | =item Fatal |
391 | |
19799a22 |
392 | replace functions with equivalents which succeed or die |
b6c543e3 |
393 | |
f102b883 |
394 | =item Fcntl |
395 | |
396 | load the C Fcntl.h defines |
397 | |
398 | =item File::Basename |
399 | |
400 | split a pathname into pieces |
401 | |
f102b883 |
402 | =item File::Compare |
403 | |
19799a22 |
404 | Compare files or filehandles |
f102b883 |
405 | |
406 | =item File::Copy |
407 | |
19799a22 |
408 | Copy files or filehandles |
409 | |
410 | =item File::DosGlob |
411 | |
412 | DOS like globbing and then some |
f102b883 |
413 | |
414 | =item File::Find |
415 | |
416 | traverse a file tree |
417 | |
418 | =item File::Path |
419 | |
420 | create or remove a series of directories |
421 | |
f505c983 |
422 | =item File::Spec |
423 | |
424 | portably perform operations on file names |
425 | |
426 | =item File::Spec::Functions |
427 | |
19799a22 |
428 | portably perform operations on file names |
429 | |
430 | =item File::Spec::Mac |
431 | |
432 | File::Spec for MacOS |
433 | |
434 | =item File::Spec::OS2 |
435 | |
436 | methods for OS/2 file specs |
437 | |
438 | =item File::Spec::Unix |
439 | |
440 | methods used by File::Spec |
441 | |
442 | =item File::Spec::VMS |
443 | |
444 | methods for VMS file specs |
445 | |
446 | =item File::Spec::Win32 |
447 | |
448 | methods for Win32 file specs |
f505c983 |
449 | |
f102b883 |
450 | =item File::stat |
451 | |
19799a22 |
452 | by-name interface to Perl's built-in stat() functions |
f102b883 |
453 | |
454 | =item FileCache |
455 | |
456 | keep more files open than the system permits |
457 | |
458 | =item FileHandle |
459 | |
460 | supply object methods for filehandles |
461 | |
462 | =item FindBin |
463 | |
19799a22 |
464 | Locate directory of original perl script |
f102b883 |
465 | |
466 | =item GDBM_File |
467 | |
19799a22 |
468 | Perl5 access to the gdbm library. |
f102b883 |
469 | |
470 | =item Getopt::Long |
471 | |
472 | extended processing of command line options |
473 | |
474 | =item Getopt::Std |
475 | |
19799a22 |
476 | Process single-character switches with switch clustering |
f102b883 |
477 | |
478 | =item I18N::Collate |
479 | |
480 | compare 8-bit scalar data according to the current locale |
481 | |
482 | =item IO |
483 | |
484 | load various IO modules |
485 | |
19799a22 |
486 | =item IO::Dir |
487 | |
488 | supply object methods for directory handles |
489 | |
f102b883 |
490 | =item IO::File |
491 | |
492 | supply object methods for filehandles |
493 | |
494 | =item IO::Handle |
495 | |
496 | supply object methods for I/O handles |
497 | |
498 | =item IO::Pipe |
499 | |
500 | supply object methods for pipes |
501 | |
19799a22 |
502 | =item IO::Poll |
503 | |
504 | Object interface to system poll call |
505 | |
f102b883 |
506 | =item IO::Seekable |
507 | |
508 | supply seek based methods for I/O objects |
509 | |
510 | =item IO::Select |
511 | |
512 | OO interface to the select system call |
513 | |
514 | =item IO::Socket |
515 | |
19799a22 |
516 | Object interface to socket communications |
517 | |
518 | =item IO::Socket::INET |
519 | |
520 | Object interface for AF_INET domain sockets |
521 | |
522 | =item IO::Socket::UNIX |
523 | |
524 | Object interface for AF_UNIX domain sockets |
525 | |
526 | =item IPC::Msg |
527 | |
528 | SysV Msg IPC object class |
f102b883 |
529 | |
530 | =item IPC::Open2 |
531 | |
532 | open a process for both reading and writing |
533 | |
534 | =item IPC::Open3 |
535 | |
536 | open a process for reading, writing, and error handling |
537 | |
19799a22 |
538 | =item IPC::Semaphore |
539 | |
540 | SysV Semaphore IPC object class |
541 | |
542 | =item IPC::SysV |
543 | |
544 | SysV IPC constants |
545 | |
f102b883 |
546 | =item Math::BigFloat |
547 | |
19799a22 |
548 | Arbitrary length float math package |
f102b883 |
549 | |
550 | =item Math::BigInt |
551 | |
19799a22 |
552 | Arbitrary size integer math package |
f102b883 |
553 | |
554 | =item Math::Complex |
555 | |
556 | complex numbers and associated mathematical functions |
557 | |
404b15a1 |
558 | =item Math::Trig |
559 | |
19799a22 |
560 | trigonometric functions |
404b15a1 |
561 | |
f102b883 |
562 | =item NDBM_File |
563 | |
19799a22 |
564 | Tied access to ndbm files |
f102b883 |
565 | |
566 | =item Net::Ping |
567 | |
19799a22 |
568 | check a remote host for reachability |
f102b883 |
569 | |
570 | =item Net::hostent |
571 | |
19799a22 |
572 | by-name interface to Perl's built-in gethost*() functions |
f102b883 |
573 | |
574 | =item Net::netent |
575 | |
19799a22 |
576 | by-name interface to Perl's built-in getnet*() functions |
f102b883 |
577 | |
578 | =item Net::protoent |
579 | |
19799a22 |
580 | by-name interface to Perl's built-in getproto*() functions |
f102b883 |
581 | |
582 | =item Net::servent |
583 | |
19799a22 |
584 | by-name interface to Perl's built-in getserv*() functions |
f102b883 |
585 | |
19799a22 |
586 | =item O |
f102b883 |
587 | |
19799a22 |
588 | Generic interface to Perl Compiler backends |
f102b883 |
589 | |
19799a22 |
590 | =item Opcode |
f102b883 |
591 | |
19799a22 |
592 | Disable named opcodes when compiling perl code |
f102b883 |
593 | |
594 | =item POSIX |
595 | |
19799a22 |
596 | Perl interface to IEEE Std 1003.1 |
597 | |
598 | =item Pod::Html |
599 | |
600 | module to convert pod files to HTML |
601 | |
602 | =item Pod::Text |
603 | |
604 | convert POD data to formatted ASCII text |
f102b883 |
605 | |
606 | =item SDBM_File |
607 | |
19799a22 |
608 | Tied access to sdbm files |
f102b883 |
609 | |
610 | =item Safe |
611 | |
19799a22 |
612 | Compile and execute code in restricted compartments |
f102b883 |
613 | |
614 | =item Search::Dict |
615 | |
616 | search for key in dictionary file |
617 | |
618 | =item SelectSaver |
619 | |
620 | save and restore selected file handle |
621 | |
622 | =item SelfLoader |
623 | |
624 | load functions only on demand |
625 | |
626 | =item Shell |
627 | |
19799a22 |
628 | run shell commands transparently within perl |
f102b883 |
629 | |
630 | =item Socket |
631 | |
632 | load the C socket.h defines and structure manipulators |
633 | |
634 | =item Symbol |
635 | |
636 | manipulate Perl symbols and their names |
637 | |
638 | =item Sys::Hostname |
639 | |
19799a22 |
640 | Try every conceivable way to get hostname |
f102b883 |
641 | |
642 | =item Sys::Syslog |
643 | |
19799a22 |
644 | Perl interface to the UNIX syslog(3) calls |
f102b883 |
645 | |
646 | =item Term::Cap |
647 | |
19799a22 |
648 | Perl termcap interface |
f102b883 |
649 | |
650 | =item Term::Complete |
651 | |
19799a22 |
652 | Perl word completion module |
f102b883 |
653 | |
654 | =item Term::ReadLine |
655 | |
19799a22 |
656 | Perl interface to various C<readline> packages. |
657 | |
658 | =item Test |
659 | |
660 | provides a simple framework for writing test scripts |
f102b883 |
661 | |
662 | =item Test::Harness |
663 | |
19799a22 |
664 | run perl standard test scripts with statistics |
f102b883 |
665 | |
666 | =item Text::Abbrev |
667 | |
668 | create an abbreviation table from a list |
669 | |
670 | =item Text::ParseWords |
671 | |
19799a22 |
672 | parse text into an array of tokens or array of arrays |
f102b883 |
673 | |
674 | =item Text::Soundex |
675 | |
19799a22 |
676 | Implementation of the Soundex Algorithm as Described by Knuth |
f102b883 |
677 | |
19799a22 |
678 | =item Text::Tabs -- expand and unexpand tabs per the unix expand(1) and unexpand(1) |
f102b883 |
679 | |
680 | =item Text::Wrap |
681 | |
682 | line wrapping to form simple paragraphs |
683 | |
19799a22 |
684 | =item Thread |
685 | |
686 | multithreading |
687 | |
688 | =item Thread::Queue |
689 | |
690 | thread-safe queues |
691 | |
692 | =item Thread::Semaphore |
693 | |
694 | thread-safe semaphores |
695 | |
696 | =item Thread::Signal |
697 | |
698 | Start a thread which runs signal handlers reliably |
699 | |
700 | =item Thread::Specific |
701 | |
702 | thread-specific keys |
703 | |
704 | =item Tie::Array |
705 | |
706 | base class for tied arrays |
707 | |
708 | =item Tie::Handle |
709 | |
710 | base class definitions for tied handles |
711 | |
712 | =item Tie::Hash, Tie::StdHash |
f102b883 |
713 | |
714 | base class definitions for tied hashes |
715 | |
716 | =item Tie::RefHash |
717 | |
19799a22 |
718 | use references as hash keys |
f102b883 |
719 | |
19799a22 |
720 | =item Tie::Scalar, Tie::StdScalar |
f102b883 |
721 | |
722 | base class definitions for tied scalars |
723 | |
724 | =item Tie::SubstrHash |
725 | |
19799a22 |
726 | Fixed-table-size, fixed-key-length hashing |
f102b883 |
727 | |
728 | =item Time::Local |
729 | |
730 | efficiently compute time from local and GMT time |
731 | |
732 | =item Time::gmtime |
733 | |
19799a22 |
734 | by-name interface to Perl's built-in gmtime() function |
f102b883 |
735 | |
736 | =item Time::localtime |
737 | |
19799a22 |
738 | by-name interface to Perl's built-in localtime() function |
f102b883 |
739 | |
740 | =item Time::tm |
741 | |
742 | internal object used by Time::gmtime and Time::localtime |
743 | |
744 | =item UNIVERSAL |
745 | |
746 | base class for ALL classes (blessed references) |
747 | |
748 | =item User::grent |
749 | |
19799a22 |
750 | by-name interface to Perl's built-in getgr*() functions |
f102b883 |
751 | |
752 | =item User::pwent |
753 | |
19799a22 |
754 | by-name interface to Perl's built-in getpw*() functions |
f102b883 |
755 | |
756 | =back |
757 | |
19799a22 |
758 | To find out I<all> modules installed on your system, including |
759 | those without documentation or outside the standard release, |
760 | jus tdo this: |
f102b883 |
761 | |
5a964f20 |
762 | % find `perl -e 'print "@INC"'` -name '*.pm' -print |
f102b883 |
763 | |
19799a22 |
764 | They should all have their own documentation installed and accessible |
765 | via your system man(1) command. If you do not have a B<find> |
766 | program, you can use the Perl B<find2perl> program instead, which |
767 | generates Perl code as output you can run through perl. If you |
768 | have a B<man> program but it doesn't find your modules, you'll have |
769 | to fix your manpath. See L<perl> for details. If you have no |
770 | system B<man> command, you might try the B<perldoc> program. |
f102b883 |
771 | |
772 | =head2 Extension Modules |
773 | |
19799a22 |
774 | Extension modules are written in C (or a mix of Perl and C). They |
775 | are usually dynamically loaded into Perl if and when you need them, |
776 | but may also be be linked in statically. Supported extension modules |
777 | include Socket, Fcntl, and POSIX. |
f102b883 |
778 | |
779 | Many popular C extension modules do not come bundled (at least, not |
19799a22 |
780 | completely) due to their sizes, volatility, or simply lack of time |
781 | for adequate testing and configuration across the multitude of |
782 | platforms on which Perl was beta-tested. You are encouraged to |
783 | look for them on CPAN (described below), or using web search engines |
784 | like Alta Vista or Deja News. |
f102b883 |
785 | |
786 | =head1 CPAN |
787 | |
19799a22 |
788 | CPAN stands for Comprehensive Perl Archive Network; it's a globally |
789 | replicated trove of Perl materials, including documentation, style |
790 | guides, tricks and trap, alternate ports to non-Unix systems and |
791 | occasional binary distributions for these. Search engines for |
792 | CPAN can be found at http://cpan.perl.com/ and at |
793 | http://theory.uwinnipeg.ca/mod_perl/cpan-search.pl . |
794 | |
795 | Most importantly, CPAN includes around a thousand unbundled modules, |
796 | some of which require a C compiler to build. Major categories of |
797 | modules are: |
f102b883 |
798 | |
799 | =over |
800 | |
801 | =item * |
802 | Language Extensions and Documentation Tools |
803 | |
804 | =item * |
805 | Development Support |
806 | |
807 | =item * |
808 | Operating System Interfaces |
809 | |
810 | =item * |
811 | Networking, Device Control (modems) and InterProcess Communication |
812 | |
813 | =item * |
814 | Data Types and Data Type Utilities |
815 | |
816 | =item * |
817 | Database Interfaces |
818 | |
819 | =item * |
820 | User Interfaces |
821 | |
822 | =item * |
823 | Interfaces to / Emulations of Other Programming Languages |
824 | |
825 | =item * |
826 | File Names, File Systems and File Locking (see also File Handles) |
827 | |
828 | =item * |
829 | String Processing, Language Text Processing, Parsing, and Searching |
830 | |
831 | =item * |
832 | Option, Argument, Parameter, and Configuration File Processing |
833 | |
834 | =item * |
835 | Internationalization and Locale |
836 | |
837 | =item * |
838 | Authentication, Security, and Encryption |
839 | |
840 | =item * |
841 | World Wide Web, HTML, HTTP, CGI, MIME |
842 | |
843 | =item * |
844 | Server and Daemon Utilities |
845 | |
846 | =item * |
847 | Archiving and Compression |
848 | |
849 | =item * |
850 | Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing |
851 | |
852 | =item * |
853 | Mail and Usenet News |
854 | |
855 | =item * |
856 | Control Flow Utilities (callbacks and exceptions etc) |
857 | |
858 | =item * |
859 | File Handle and Input/Output Stream Utilities |
860 | |
861 | =item * |
862 | Miscellaneous Modules |
863 | |
864 | =back |
865 | |
19799a22 |
866 | Registered CPAN sites as of this writing include the following. |
f102b883 |
867 | You should try to choose one close to you: |
868 | |
869 | =over |
870 | |
19799a22 |
871 | =item Africa |
f102b883 |
872 | |
be94a901 |
873 | South Africa ftp://ftp.is.co.za/programming/perl/CPAN/ |
874 | ftp://ftpza.co.za/pub/mirrors/cpan/ |
f102b883 |
875 | |
19799a22 |
876 | =item Asia |
f102b883 |
877 | |
be94a901 |
878 | China ftp://freesoft.cei.gov.cn/pub/languages/perl/CPAN/ |
879 | Hong Kong ftp://ftp.hkstar.com/pub/CPAN/ |
880 | Israel ftp://bioinfo.weizmann.ac.il/pub/software/perl/CPAN/ |
881 | Japan ftp://ftp.dti.ad.jp/pub/lang/CPAN/ |
882 | ftp://ftp.jaist.ac.jp/pub/lang/perl/CPAN/ |
883 | ftp://ftp.lab.kdd.co.jp/lang/perl/CPAN/ |
884 | ftp://ftp.meisei-u.ac.jp/pub/CPAN/ |
19799a22 |
885 | ftp://ftp.ring.gr.jp/pub/lang/perl/CPAN/ |
be94a901 |
886 | ftp://mirror.nucba.ac.jp/mirror/Perl/ |
887 | Singapore ftp://ftp.nus.edu.sg/pub/unix/perl/CPAN/ |
888 | South Korea ftp://ftp.bora.net/pub/CPAN/ |
889 | ftp://ftp.nuri.net/pub/CPAN/ |
890 | Taiwan ftp://ftp.wownet.net/pub2/PERL/ |
891 | ftp://ftp1.sinica.edu.tw/pub1/perl/CPAN/ |
892 | Thailand ftp://ftp.cs.riubon.ac.th/pub/mirrors/CPAN/ |
893 | ftp://ftp.nectec.or.th/pub/mirrors/CPAN/ |
f102b883 |
894 | |
19799a22 |
895 | =item Australasia |
f102b883 |
896 | |
be94a901 |
897 | Australia ftp://cpan.topend.com.au/pub/CPAN/ |
898 | ftp://ftp.labyrinth.net.au/pub/perl/CPAN/ |
899 | ftp://ftp.sage-au.org.au/pub/compilers/perl/CPAN/ |
900 | ftp://mirror.aarnet.edu.au/pub/perl/CPAN/ |
901 | New Zealand ftp://ftp.auckland.ac.nz/pub/perl/CPAN/ |
902 | ftp://sunsite.net.nz/pub/languages/perl/CPAN/ |
903 | |
be94a901 |
904 | Central America |
905 | |
906 | Costa Rica ftp://ftp.ucr.ac.cr/pub/Unix/CPAN/ |
f102b883 |
907 | |
19799a22 |
908 | =item Europe |
f102b883 |
909 | |
be94a901 |
910 | Austria ftp://ftp.tuwien.ac.at/pub/languages/perl/CPAN/ |
911 | Belgium ftp://ftp.kulnet.kuleuven.ac.be/pub/mirror/CPAN/ |
912 | Bulgaria ftp://ftp.ntrl.net/pub/mirrors/CPAN/ |
913 | Croatia ftp://ftp.linux.hr/pub/CPAN/ |
914 | Czech Republic ftp://ftp.fi.muni.cz/pub/perl/ |
915 | ftp://sunsite.mff.cuni.cz/Languages/Perl/CPAN/ |
916 | Denmark ftp://sunsite.auc.dk/pub/languages/perl/CPAN/ |
917 | Estonia ftp://ftp.ut.ee/pub/languages/perl/CPAN/ |
918 | Finland ftp://ftp.funet.fi/pub/languages/perl/CPAN/ |
919 | France ftp://ftp.lip6.fr/pub/perl/CPAN/ |
920 | ftp://ftp.oleane.net/pub/mirrors/CPAN/ |
921 | ftp://ftp.pasteur.fr/pub/computing/CPAN/ |
922 | Germany ftp://ftp.archive.de.uu.net/pub/CPAN/ |
923 | ftp://ftp.gmd.de/packages/CPAN/ |
924 | ftp://ftp.gwdg.de/pub/languages/perl/CPAN/ |
925 | ftp://ftp.leo.org/pub/comp/programming/languages/script/perl/CPAN/ |
926 | ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/ |
927 | ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/ |
928 | ftp://ftp.uni-erlangen.de/pub/source/CPAN/ |
929 | ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/ |
930 | Greece ftp://ftp.ntua.gr/pub/lang/perl/ |
931 | Hungary ftp://ftp.kfki.hu/pub/packages/perl/CPAN/ |
932 | Ireland ftp://sunsite.compapp.dcu.ie/pub/perl/ |
933 | Italy ftp://cis.uniRoma2.it/CPAN/ |
934 | ftp://ftp.flashnet.it/pub/CPAN/ |
19799a22 |
935 | ftp://ftp.unina.it/pub/Other/CPAN/ |
be94a901 |
936 | ftp://ftp.unipi.it/pub/mirror/perl/CPAN/ |
937 | Netherlands ftp://ftp.cs.uu.nl/mirror/CPAN/ |
19799a22 |
938 | ftp://ftp.EU.net/packages/cpan/ |
be94a901 |
939 | ftp://ftp.nluug.nl/pub/languages/perl/CPAN/ |
940 | Norway ftp://ftp.uit.no/pub/languages/perl/cpan/ |
941 | ftp://sunsite.uio.no/pub/languages/perl/CPAN/ |
942 | Poland ftp://ftp.man.szczecin.pl/pub/perl/CPAN/ |
943 | ftp://ftp.man.torun.pl/pub/doc/CPAN/ |
944 | ftp://ftp.pk.edu.pl/pub/lang/perl/CPAN/ |
945 | ftp://sunsite.icm.edu.pl/pub/CPAN/ |
946 | Portugal ftp://ftp.ci.uminho.pt/pub/mirrors/cpan/ |
19799a22 |
947 | ftp://ftp.ist.utl.pt/pub/CPAN/ |
be94a901 |
948 | ftp://ftp.ua.pt/pub/CPAN/ |
949 | Romania ftp://ftp.dntis.ro/pub/mirrors/perl-cpan/ |
950 | ftp://ftp.dnttm.ro/pub/CPAN/ |
19799a22 |
951 | Russia ftp://ftp.chg.ru/pub/lang/perl/CPAN/ |
be94a901 |
952 | ftp://ftp.sai.msu.su/pub/lang/perl/CPAN/ |
953 | Slovakia ftp://ftp.entry.sk/pub/languages/perl/CPAN/ |
954 | Slovenia ftp://ftp.arnes.si/software/perl/CPAN/ |
955 | Spain ftp://ftp.etse.urv.es/pub/perl/ |
956 | ftp://ftp.rediris.es/mirror/CPAN/ |
957 | Sweden ftp://ftp.sunet.se/pub/lang/perl/CPAN/ |
958 | Switzerland ftp://sunsite.cnlab-switch.ch/mirror/CPAN/ |
959 | Turkey ftp://sunsite.bilkent.edu.tr/pub/languages/CPAN/ |
960 | United Kingdom ftp://ftp.demon.co.uk/pub/mirrors/perl/CPAN/ |
961 | ftp://ftp.flirble.org/pub/languages/perl/CPAN/ |
962 | ftp://ftp.plig.org/pub/CPAN/ |
963 | ftp://sunsite.doc.ic.ac.uk/packages/CPAN/ |
964 | ftp://unix.hensa.ac.uk/mirrors/perl-CPAN/ |
f102b883 |
965 | |
19799a22 |
966 | =item North America |
f102b883 |
967 | |
be94a901 |
968 | Alberta ftp://sunsite.ualberta.ca/pub/Mirror/CPAN/ |
19799a22 |
969 | California ftp://cpan.nas.nasa.gov/pub/perl/CPAN/ |
970 | ftp://ftp.cdrom.com/pub/perl/CPAN/ |
be94a901 |
971 | ftp://ftp.digital.com/pub/plan/perl/CPAN/ |
972 | Colorado ftp://ftp.cs.colorado.edu/pub/perl/CPAN/ |
973 | Florida ftp://ftp.cise.ufl.edu/pub/perl/CPAN/ |
974 | Illinois ftp://uiarchive.uiuc.edu/pub/lang/perl/CPAN/ |
975 | Indiana ftp://csociety-ftp.ecn.purdue.edu/pub/CPAN/ |
976 | ftp://ftp.uwsg.indiana.edu/pub/perl/CPAN/ |
977 | Manitoba ftp://theory.uwinnipeg.ca/pub/CPAN/ |
978 | Massachusetts ftp://ftp.ccs.neu.edu/net/mirrors/ftp.funet.fi/pub/languages/perl/CPAN/ |
979 | ftp://ftp.iguide.com/pub/mirrors/packages/perl/CPAN/ |
19799a22 |
980 | Mexico ftp://ftp.msg.com.mx/pub/CPAN/ |
981 | Minnesota ftp://ftp.midearthbbs.com/CPAN/ |
be94a901 |
982 | New York ftp://ftp.rge.com/pub/languages/perl/ |
983 | North Carolina ftp://ftp.duke.edu/pub/perl/ |
984 | Oklahoma ftp://ftp.ou.edu/mirrors/CPAN/ |
19799a22 |
985 | Ontario ftp://ftp.crc.ca/pub/packages/lang/perl/CPAN/ |
be94a901 |
986 | Oregon ftp://ftp.orst.edu/pub/packages/CPAN/ |
987 | Pennsylvania ftp://ftp.epix.net/pub/languages/perl/ |
988 | Texas ftp://ftp.sedl.org/pub/mirrors/CPAN/ |
989 | Utah ftp://mirror.xmission.com/CPAN/ |
990 | Virginia ftp://ftp.perl.org/pub/perl/CPAN/ |
991 | ftp://ruff.cs.jmu.edu/pub/CPAN/ |
19799a22 |
992 | Washington ftp://ftp-mirror.internap.com/pub/CPAN/ |
993 | ftp://ftp.spu.edu/pub/CPAN/ |
f102b883 |
994 | |
19799a22 |
995 | =item South America |
f102b883 |
996 | |
be94a901 |
997 | Brazil ftp://cpan.if.usp.br/pub/mirror/CPAN/ |
19799a22 |
998 | Chile ftp://sunsite.dcc.uchile.cl/pub/Lang/perl/CPAN/ |
f102b883 |
999 | |
1000 | =back |
1001 | |
1002 | For an up-to-date listing of CPAN sites, |
19799a22 |
1003 | see http://www.perl.com/perl/CPAN or ftp://www.perl.com/perl/ . |
f102b883 |
1004 | |
1005 | =head1 Modules: Creation, Use, and Abuse |
1006 | |
1007 | (The following section is borrowed directly from Tim Bunce's modules |
1008 | file, available at your nearest CPAN site.) |
1009 | |
1010 | Perl implements a class using a package, but the presence of a |
1011 | package doesn't imply the presence of a class. A package is just a |
1012 | namespace. A class is a package that provides subroutines that can be |
1013 | used as methods. A method is just a subroutine that expects, as its |
1014 | first argument, either the name of a package (for "static" methods), |
1015 | or a reference to something (for "virtual" methods). |
1016 | |
1017 | A module is a file that (by convention) provides a class of the same |
1018 | name (sans the .pm), plus an import method in that class that can be |
1019 | called to fetch exported symbols. This module may implement some of |
1020 | its methods by loading dynamic C or C++ objects, but that should be |
1021 | totally transparent to the user of the module. Likewise, the module |
1022 | might set up an AUTOLOAD function to slurp in subroutine definitions on |
1023 | demand, but this is also transparent. Only the F<.pm> file is required to |
1024 | exist. See L<perlsub>, L<perltoot>, and L<AutoLoader> for details about |
1025 | the AUTOLOAD mechanism. |
1026 | |
1027 | =head2 Guidelines for Module Creation |
1028 | |
1029 | =over 4 |
1030 | |
1031 | =item Do similar modules already exist in some form? |
1032 | |
1033 | If so, please try to reuse the existing modules either in whole or |
1034 | by inheriting useful features into a new class. If this is not |
1035 | practical try to get together with the module authors to work on |
1036 | extending or enhancing the functionality of the existing modules. |
1037 | A perfect example is the plethora of packages in perl4 for dealing |
1038 | with command line options. |
1039 | |
1040 | If you are writing a module to expand an already existing set of |
1041 | modules, please coordinate with the author of the package. It |
1042 | helps if you follow the same naming scheme and module interaction |
1043 | scheme as the original author. |
1044 | |
1045 | =item Try to design the new module to be easy to extend and reuse. |
1046 | |
19799a22 |
1047 | Always use B<-w>. |
1048 | |
f102b883 |
1049 | Use blessed references. Use the two argument form of bless to bless |
1050 | into the class name given as the first parameter of the constructor, |
1051 | e.g.,: |
1052 | |
1053 | sub new { |
1054 | my $class = shift; |
1055 | return bless {}, $class; |
1056 | } |
1057 | |
1058 | or even this if you'd like it to be used as either a static |
1059 | or a virtual method. |
1060 | |
1061 | sub new { |
1062 | my $self = shift; |
1063 | my $class = ref($self) || $self; |
1064 | return bless {}, $class; |
1065 | } |
1066 | |
1067 | Pass arrays as references so more parameters can be added later |
1068 | (it's also faster). Convert functions into methods where |
1069 | appropriate. Split large methods into smaller more flexible ones. |
1070 | Inherit methods from other modules if appropriate. |
1071 | |
1072 | Avoid class name tests like: C<die "Invalid" unless ref $ref eq 'FOO'>. |
19799a22 |
1073 | Generally you can delete the C<eq 'FOO'> part with no harm at all. |
f102b883 |
1074 | Let the objects look after themselves! Generally, avoid hard-wired |
1075 | class names as far as possible. |
1076 | |
1077 | Avoid C<$r-E<gt>Class::func()> where using C<@ISA=qw(... Class ...)> and |
1078 | C<$r-E<gt>func()> would work (see L<perlbot> for more details). |
1079 | |
1080 | Use autosplit so little used or newly added functions won't be a |
5a964f20 |
1081 | burden to programs that don't use them. Add test functions to |
f102b883 |
1082 | the module after __END__ either using AutoSplit or by saying: |
1083 | |
1084 | eval join('',<main::DATA>) || die $@ unless caller(); |
1085 | |
1086 | Does your module pass the 'empty subclass' test? If you say |
19799a22 |
1087 | C<@SUBCLASS::ISA = qw(YOURCLASS);> your applications should be able |
f102b883 |
1088 | to use SUBCLASS in exactly the same way as YOURCLASS. For example, |
1089 | does your application still work if you change: C<$obj = new YOURCLASS;> |
1090 | into: C<$obj = new SUBCLASS;> ? |
1091 | |
1092 | Avoid keeping any state information in your packages. It makes it |
1093 | difficult for multiple other packages to use yours. Keep state |
1094 | information in objects. |
1095 | |
19799a22 |
1096 | Always use B<-w>. |
1097 | |
1098 | Try to C<use strict;> (or C<use strict qw(...);>). |
f102b883 |
1099 | Remember that you can add C<no strict qw(...);> to individual blocks |
19799a22 |
1100 | of code that need less strictness. |
1101 | |
1102 | Always use B<-w>. |
1103 | |
f102b883 |
1104 | Follow the guidelines in the perlstyle(1) manual. |
1105 | |
19799a22 |
1106 | Always use B<-w>. |
1107 | |
f102b883 |
1108 | =item Some simple style guidelines |
1109 | |
5a964f20 |
1110 | The perlstyle manual supplied with Perl has many helpful points. |
f102b883 |
1111 | |
1112 | Coding style is a matter of personal taste. Many people evolve their |
1113 | style over several years as they learn what helps them write and |
1114 | maintain good code. Here's one set of assorted suggestions that |
1115 | seem to be widely used by experienced developers: |
1116 | |
1117 | Use underscores to separate words. It is generally easier to read |
1118 | $var_names_like_this than $VarNamesLikeThis, especially for |
1119 | non-native speakers of English. It's also a simple rule that works |
1120 | consistently with VAR_NAMES_LIKE_THIS. |
1121 | |
1122 | Package/Module names are an exception to this rule. Perl informally |
1123 | reserves lowercase module names for 'pragma' modules like integer |
1124 | and strict. Other modules normally begin with a capital letter and |
1125 | use mixed case with no underscores (need to be short and portable). |
1126 | |
1127 | You may find it helpful to use letter case to indicate the scope |
1128 | or nature of a variable. For example: |
1129 | |
5a964f20 |
1130 | $ALL_CAPS_HERE constants only (beware clashes with Perl vars) |
f102b883 |
1131 | $Some_Caps_Here package-wide global/static |
1132 | $no_caps_here function scope my() or local() variables |
1133 | |
1134 | Function and method names seem to work best as all lowercase. |
1135 | e.g., C<$obj-E<gt>as_string()>. |
1136 | |
1137 | You can use a leading underscore to indicate that a variable or |
1138 | function should not be used outside the package that defined it. |
1139 | |
1140 | =item Select what to export. |
1141 | |
1142 | Do NOT export method names! |
1143 | |
1144 | Do NOT export anything else by default without a good reason! |
1145 | |
1146 | Exports pollute the namespace of the module user. If you must |
1147 | export try to use @EXPORT_OK in preference to @EXPORT and avoid |
1148 | short or common names to reduce the risk of name clashes. |
1149 | |
1150 | Generally anything not exported is still accessible from outside the |
1151 | module using the ModuleName::item_name (or C<$blessed_ref-E<gt>method>) |
1152 | syntax. By convention you can use a leading underscore on names to |
1153 | indicate informally that they are 'internal' and not for public use. |
1154 | |
1155 | (It is actually possible to get private functions by saying: |
1156 | C<my $subref = sub { ... }; &$subref;>. But there's no way to call that |
1157 | directly as a method, because a method must have a name in the symbol |
1158 | table.) |
1159 | |
1160 | As a general rule, if the module is trying to be object oriented |
1161 | then export nothing. If it's just a collection of functions then |
1162 | @EXPORT_OK anything but use @EXPORT with caution. |
1163 | |
1164 | =item Select a name for the module. |
1165 | |
1166 | This name should be as descriptive, accurate, and complete as |
1167 | possible. Avoid any risk of ambiguity. Always try to use two or |
1168 | more whole words. Generally the name should reflect what is special |
1169 | about what the module does rather than how it does it. Please use |
1170 | nested module names to group informally or categorize a module. |
1171 | There should be a very good reason for a module not to have a nested name. |
1172 | Module names should begin with a capital letter. |
1173 | |
1174 | Having 57 modules all called Sort will not make life easy for anyone |
1175 | (though having 23 called Sort::Quick is only marginally better :-). |
1176 | Imagine someone trying to install your module alongside many others. |
1177 | If in any doubt ask for suggestions in comp.lang.perl.misc. |
1178 | |
1179 | If you are developing a suite of related modules/classes it's good |
1180 | practice to use nested classes with a common prefix as this will |
1181 | avoid namespace clashes. For example: Xyz::Control, Xyz::View, |
1182 | Xyz::Model etc. Use the modules in this list as a naming guide. |
1183 | |
1184 | If adding a new module to a set, follow the original author's |
1185 | standards for naming modules and the interface to methods in |
1186 | those modules. |
1187 | |
1188 | To be portable each component of a module name should be limited to |
1189 | 11 characters. If it might be used on MS-DOS then try to ensure each is |
1190 | unique in the first 8 characters. Nested modules make this easier. |
1191 | |
1192 | =item Have you got it right? |
1193 | |
1194 | How do you know that you've made the right decisions? Have you |
1195 | picked an interface design that will cause problems later? Have |
1196 | you picked the most appropriate name? Do you have any questions? |
1197 | |
1198 | The best way to know for sure, and pick up many helpful suggestions, |
1199 | is to ask someone who knows. Comp.lang.perl.misc is read by just about |
1200 | all the people who develop modules and it's the best place to ask. |
1201 | |
1202 | All you need to do is post a short summary of the module, its |
1203 | purpose and interfaces. A few lines on each of the main methods is |
1204 | probably enough. (If you post the whole module it might be ignored |
1205 | by busy people - generally the very people you want to read it!) |
1206 | |
1207 | Don't worry about posting if you can't say when the module will be |
1208 | ready - just say so in the message. It might be worth inviting |
1209 | others to help you, they may be able to complete it for you! |
1210 | |
1211 | =item README and other Additional Files. |
1212 | |
1213 | It's well known that software developers usually fully document the |
1214 | software they write. If, however, the world is in urgent need of |
1215 | your software and there is not enough time to write the full |
1216 | documentation please at least provide a README file containing: |
1217 | |
1218 | =over 10 |
1219 | |
1220 | =item * |
1221 | A description of the module/package/extension etc. |
1222 | |
1223 | =item * |
1224 | A copyright notice - see below. |
1225 | |
1226 | =item * |
1227 | Prerequisites - what else you may need to have. |
1228 | |
1229 | =item * |
1230 | How to build it - possible changes to Makefile.PL etc. |
1231 | |
1232 | =item * |
1233 | How to install it. |
1234 | |
1235 | =item * |
1236 | Recent changes in this release, especially incompatibilities |
1237 | |
1238 | =item * |
1239 | Changes / enhancements you plan to make in the future. |
1240 | |
1241 | =back |
1242 | |
1243 | If the README file seems to be getting too large you may wish to |
1244 | split out some of the sections into separate files: INSTALL, |
1245 | Copying, ToDo etc. |
1246 | |
1247 | =over 4 |
1248 | |
1249 | =item Adding a Copyright Notice. |
1250 | |
1251 | How you choose to license your work is a personal decision. |
1252 | The general mechanism is to assert your Copyright and then make |
1253 | a declaration of how others may copy/use/modify your work. |
1254 | |
1255 | Perl, for example, is supplied with two types of licence: The GNU |
1256 | GPL and The Artistic Licence (see the files README, Copying, and |
1257 | Artistic). Larry has good reasons for NOT just using the GNU GPL. |
1258 | |
1259 | My personal recommendation, out of respect for Larry, Perl, and the |
5a964f20 |
1260 | Perl community at large is to state something simply like: |
f102b883 |
1261 | |
1262 | Copyright (c) 1995 Your Name. All rights reserved. |
1263 | This program is free software; you can redistribute it and/or |
1264 | modify it under the same terms as Perl itself. |
1265 | |
1266 | This statement should at least appear in the README file. You may |
1267 | also wish to include it in a Copying file and your source files. |
1268 | Remember to include the other words in addition to the Copyright. |
1269 | |
1270 | =item Give the module a version/issue/release number. |
1271 | |
1272 | To be fully compatible with the Exporter and MakeMaker modules you |
1273 | should store your module's version number in a non-my package |
1274 | variable called $VERSION. This should be a floating point |
1275 | number with at least two digits after the decimal (i.e., hundredths, |
1276 | e.g, C<$VERSION = "0.01">). Don't use a "1.3.2" style version. |
19799a22 |
1277 | See L<Exporter> for details. |
f102b883 |
1278 | |
1279 | It may be handy to add a function or method to retrieve the number. |
1280 | Use the number in announcements and archive file names when |
1281 | releasing the module (ModuleName-1.02.tar.Z). |
1282 | See perldoc ExtUtils::MakeMaker.pm for details. |
1283 | |
1284 | =item How to release and distribute a module. |
1285 | |
1286 | It's good idea to post an announcement of the availability of your |
1287 | module (or the module itself if small) to the comp.lang.perl.announce |
1288 | Usenet newsgroup. This will at least ensure very wide once-off |
1289 | distribution. |
1290 | |
19799a22 |
1291 | If possible, register the module with CPAN. You should |
f102b883 |
1292 | include details of its location in your announcement. |
1293 | |
1294 | Some notes about ftp archives: Please use a long descriptive file |
5a964f20 |
1295 | name that includes the version number. Most incoming directories |
f102b883 |
1296 | will not be readable/listable, i.e., you won't be able to see your |
1297 | file after uploading it. Remember to send your email notification |
1298 | message as soon as possible after uploading else your file may get |
1299 | deleted automatically. Allow time for the file to be processed |
1300 | and/or check the file has been processed before announcing its |
1301 | location. |
1302 | |
1303 | FTP Archives for Perl Modules: |
1304 | |
1305 | Follow the instructions and links on |
1306 | |
1307 | http://franz.ww.tu-berlin.de/modulelist |
1308 | |
1309 | or upload to one of these sites: |
1310 | |
1311 | ftp://franz.ww.tu-berlin.de/incoming |
1312 | ftp://ftp.cis.ufl.edu/incoming |
1313 | |
1314 | and notify <F<upload@franz.ww.tu-berlin.de>>. |
1315 | |
1316 | By using the WWW interface you can ask the Upload Server to mirror |
1317 | your modules from your ftp or WWW site into your own directory on |
1318 | CPAN! |
1319 | |
1320 | Please remember to send me an updated entry for the Module list! |
1321 | |
1322 | =item Take care when changing a released module. |
1323 | |
7b8d334a |
1324 | Always strive to remain compatible with previous released versions. |
1325 | Otherwise try to add a mechanism to revert to the |
19799a22 |
1326 | old behavior if people rely on it. Document incompatible changes. |
f102b883 |
1327 | |
1328 | =back |
1329 | |
1330 | =back |
1331 | |
1332 | =head2 Guidelines for Converting Perl 4 Library Scripts into Modules |
1333 | |
1334 | =over 4 |
1335 | |
1336 | =item There is no requirement to convert anything. |
1337 | |
1338 | If it ain't broke, don't fix it! Perl 4 library scripts should |
1339 | continue to work with no problems. You may need to make some minor |
1340 | changes (like escaping non-array @'s in double quoted strings) but |
1341 | there is no need to convert a .pl file into a Module for just that. |
1342 | |
1343 | =item Consider the implications. |
1344 | |
5a964f20 |
1345 | All Perl applications that make use of the script will need to |
f102b883 |
1346 | be changed (slightly) if the script is converted into a module. Is |
1347 | it worth it unless you plan to make other changes at the same time? |
1348 | |
1349 | =item Make the most of the opportunity. |
1350 | |
1351 | If you are going to convert the script to a module you can use the |
19799a22 |
1352 | opportunity to redesign the interface. The guidelines for module |
1353 | creation above include many of the issues you should consider. |
f102b883 |
1354 | |
1355 | =item The pl2pm utility will get you started. |
1356 | |
1357 | This utility will read *.pl files (given as parameters) and write |
1358 | corresponding *.pm files. The pl2pm utilities does the following: |
1359 | |
1360 | =over 10 |
1361 | |
1362 | =item * |
1363 | Adds the standard Module prologue lines |
1364 | |
1365 | =item * |
1366 | Converts package specifiers from ' to :: |
1367 | |
1368 | =item * |
1369 | Converts die(...) to croak(...) |
1370 | |
1371 | =item * |
1372 | Several other minor changes |
1373 | |
1374 | =back |
1375 | |
1376 | Being a mechanical process pl2pm is not bullet proof. The converted |
1377 | code will need careful checking, especially any package statements. |
1378 | Don't delete the original .pl file till the new .pm one works! |
1379 | |
1380 | =back |
1381 | |
1382 | =head2 Guidelines for Reusing Application Code |
1383 | |
1384 | =over 4 |
1385 | |
1386 | =item Complete applications rarely belong in the Perl Module Library. |
1387 | |
5a964f20 |
1388 | =item Many applications contain some Perl code that could be reused. |
f102b883 |
1389 | |
1390 | Help save the world! Share your code in a form that makes it easy |
1391 | to reuse. |
1392 | |
1393 | =item Break-out the reusable code into one or more separate module files. |
1394 | |
1395 | =item Take the opportunity to reconsider and redesign the interfaces. |
1396 | |
1397 | =item In some cases the 'application' can then be reduced to a small |
1398 | |
1399 | fragment of code built on top of the reusable modules. In these cases |
1400 | the application could invoked as: |
1401 | |
5a964f20 |
1402 | % perl -e 'use Module::Name; method(@ARGV)' ... |
f102b883 |
1403 | or |
5a964f20 |
1404 | % perl -mModule::Name ... (in perl5.002 or higher) |
f102b883 |
1405 | |
1406 | =back |
1407 | |
1408 | =head1 NOTE |
1409 | |
1410 | Perl does not enforce private and public parts of its modules as you may |
1411 | have been used to in other languages like C++, Ada, or Modula-17. Perl |
1412 | doesn't have an infatuation with enforced privacy. It would prefer |
1413 | that you stayed out of its living room because you weren't invited, not |
1414 | because it has a shotgun. |
1415 | |
1416 | The module and its user have a contract, part of which is common law, |
1417 | and part of which is "written". Part of the common law contract is |
1418 | that a module doesn't pollute any namespace it wasn't asked to. The |
1419 | written contract for the module (A.K.A. documentation) may make other |
1420 | provisions. But then you know when you C<use RedefineTheWorld> that |
1421 | you're redefining the world and willing to take the consequences. |