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f102b883 TC |
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 | ||
9 | A number of modules are included the Perl distribution. These are | |
10 | described below, and all end in F<.pm>. You may also discover files in | |
11 | the library directory that end in either F<.pl> or F<.ph>. These are old | |
12 | libraries supplied so that old programs that use them still run. The | |
13 | F<.pl> files will all eventually be converted into standard modules, and | |
14 | the F<.ph> files made by B<h2ph> will probably end up as extension modules | |
15 | made by B<h2xs>. (Some F<.ph> values may already be available through the | |
16 | POSIX module.) The B<pl2pm> file in the distribution may help in your | |
17 | conversion, but it's just a mechanical process and therefore far from | |
18 | bulletproof. | |
19 | ||
20 | =head2 Pragmatic Modules | |
21 | ||
22 | They work somewhat like pragmas in that they tend to affect the compilation of | |
23 | your program, and thus will usually work well only when used within a | |
f70b4f9c | 24 | C<use>, or C<no>. Most of these are lexically scoped, so an inner BLOCK |
f102b883 TC |
25 | may countermand any of these by saying: |
26 | ||
27 | no integer; | |
28 | no strict 'refs'; | |
29 | ||
30 | which lasts until the end of that BLOCK. | |
31 | ||
32 | Unlike the pragmas that effect the C<$^H> hints variable, the C<use | |
33 | vars> and C<use subs> declarations are not BLOCK-scoped. They allow | |
34 | you to predeclare a variables or subroutines within a particular | |
35 | I<file> rather than just a block. Such declarations are effective | |
36 | for the entire file for which they were declared. You cannot rescind | |
37 | them with C<no vars> or C<no subs>. | |
38 | ||
39 | The following pragmas are defined (and have their own documentation). | |
40 | ||
41 | =over 12 | |
42 | ||
43 | =item use autouse MODULE => qw(sub1 sub2 sub3) | |
44 | ||
45 | Defers C<require MODULE> until someone calls one of the specified | |
46 | subroutines (which must be exported by MODULE). This pragma should be | |
47 | used with caution, and only when necessary. | |
48 | ||
49 | =item blib | |
50 | ||
51 | manipulate @INC at compile time to use MakeMaker's uninstalled version | |
52 | of a package | |
53 | ||
54 | =item diagnostics | |
55 | ||
56 | force verbose warning diagnostics | |
57 | ||
58 | =item integer | |
59 | ||
60 | compute arithmetic in integer instead of double | |
61 | ||
62 | =item less | |
63 | ||
64 | request less of something from the compiler | |
65 | ||
66 | =item lib | |
67 | ||
68 | manipulate @INC at compile time | |
69 | ||
70 | =item locale | |
71 | ||
72 | use or ignore current locale for builtin operations (see L<perllocale>) | |
73 | ||
74 | =item ops | |
75 | ||
76 | restrict named opcodes when compiling or running Perl code | |
77 | ||
78 | =item overload | |
79 | ||
80 | overload basic Perl operations | |
81 | ||
b3eb6a9b GS |
82 | =item re |
83 | ||
84 | alter behaviour of regular expressions | |
85 | ||
f102b883 TC |
86 | =item sigtrap |
87 | ||
88 | enable simple signal handling | |
89 | ||
90 | =item strict | |
91 | ||
92 | restrict unsafe constructs | |
93 | ||
94 | =item subs | |
95 | ||
96 | predeclare sub names | |
97 | ||
98 | =item vmsish | |
99 | ||
100 | adopt certain VMS-specific behaviors | |
101 | ||
102 | =item vars | |
103 | ||
104 | predeclare global variable names | |
105 | ||
106 | =back | |
107 | ||
108 | =head2 Standard Modules | |
109 | ||
110 | Standard, bundled modules are all expected to behave in a well-defined | |
111 | manner with respect to namespace pollution because they use the | |
112 | Exporter module. See their own documentation for details. | |
113 | ||
114 | =over 12 | |
115 | ||
116 | =item AnyDBM_File | |
117 | ||
118 | provide framework for multiple DBMs | |
119 | ||
120 | =item AutoLoader | |
121 | ||
122 | load functions only on demand | |
123 | ||
124 | =item AutoSplit | |
125 | ||
126 | split a package for autoloading | |
127 | ||
128 | =item Benchmark | |
129 | ||
130 | benchmark running times of code | |
131 | ||
132 | =item CPAN | |
133 | ||
134 | interface to Comprehensive Perl Archive Network | |
135 | ||
136 | =item CPAN::FirstTime | |
137 | ||
138 | create a CPAN configuration file | |
139 | ||
140 | =item CPAN::Nox | |
141 | ||
142 | run CPAN while avoiding compiled extensions | |
143 | ||
144 | =item Carp | |
145 | ||
146 | warn of errors (from perspective of caller) | |
147 | ||
148 | =item Class::Struct | |
149 | ||
150 | declare struct-like datatypes | |
151 | ||
152 | =item Config | |
153 | ||
154 | access Perl configuration information | |
155 | ||
156 | =item Cwd | |
157 | ||
158 | get pathname of current working directory | |
159 | ||
160 | =item DB_File | |
161 | ||
162 | access to Berkeley DB | |
163 | ||
164 | =item Devel::SelfStubber | |
165 | ||
166 | generate stubs for a SelfLoading module | |
167 | ||
168 | =item DirHandle | |
169 | ||
170 | supply object methods for directory handles | |
171 | ||
172 | =item DynaLoader | |
173 | ||
174 | dynamically load C libraries into Perl code | |
175 | ||
176 | =item English | |
177 | ||
178 | use nice English (or awk) names for ugly punctuation variables | |
179 | ||
180 | =item Env | |
181 | ||
182 | import environment variables | |
183 | ||
184 | =item Exporter | |
185 | ||
186 | implements default import method for modules | |
187 | ||
188 | =item ExtUtils::Embed | |
189 | ||
190 | utilities for embedding Perl in C/C++ applications | |
191 | ||
192 | =item ExtUtils::Install | |
193 | ||
194 | install files from here to there | |
195 | ||
196 | =item ExtUtils::Liblist | |
197 | ||
198 | determine libraries to use and how to use them | |
199 | ||
200 | =item ExtUtils::MM_OS2 | |
201 | ||
202 | methods to override Unix behaviour in ExtUtils::MakeMaker | |
203 | ||
204 | =item ExtUtils::MM_Unix | |
205 | ||
206 | methods used by ExtUtils::MakeMaker | |
207 | ||
208 | =item ExtUtils::MM_VMS | |
209 | ||
210 | methods to override Unix behaviour in ExtUtils::MakeMaker | |
211 | ||
212 | =item ExtUtils::MakeMaker | |
213 | ||
214 | create an extension Makefile | |
215 | ||
216 | =item ExtUtils::Manifest | |
217 | ||
218 | utilities to write and check a MANIFEST file | |
219 | ||
220 | =item ExtUtils::Mkbootstrap | |
221 | ||
222 | make a bootstrap file for use by DynaLoader | |
223 | ||
224 | =item ExtUtils::Mksymlists | |
225 | ||
226 | write linker options files for dynamic extension | |
227 | ||
228 | =item ExtUtils::testlib | |
229 | ||
230 | add blib/* directories to @INC | |
231 | ||
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232 | =item Fatal |
233 | ||
234 | make errors in builtins or Perl functions fatal | |
235 | ||
f102b883 TC |
236 | =item Fcntl |
237 | ||
238 | load the C Fcntl.h defines | |
239 | ||
240 | =item File::Basename | |
241 | ||
242 | split a pathname into pieces | |
243 | ||
244 | =item File::CheckTree | |
245 | ||
246 | run many filetest checks on a tree | |
247 | ||
248 | =item File::Compare | |
249 | ||
250 | compare files or filehandles | |
251 | ||
252 | =item File::Copy | |
253 | ||
254 | copy files or filehandles | |
255 | ||
256 | =item File::Find | |
257 | ||
258 | traverse a file tree | |
259 | ||
260 | =item File::Path | |
261 | ||
262 | create or remove a series of directories | |
263 | ||
264 | =item File::stat | |
265 | ||
266 | by-name interface to Perl's builtin stat() functions | |
267 | ||
268 | =item FileCache | |
269 | ||
270 | keep more files open than the system permits | |
271 | ||
272 | =item FileHandle | |
273 | ||
274 | supply object methods for filehandles | |
275 | ||
276 | =item FindBin | |
277 | ||
5a964f20 | 278 | locate directory of original Perl script |
f102b883 TC |
279 | |
280 | =item GDBM_File | |
281 | ||
282 | access to the gdbm library | |
283 | ||
284 | =item Getopt::Long | |
285 | ||
286 | extended processing of command line options | |
287 | ||
288 | =item Getopt::Std | |
289 | ||
290 | process single-character switches with switch clustering | |
291 | ||
292 | =item I18N::Collate | |
293 | ||
294 | compare 8-bit scalar data according to the current locale | |
295 | ||
296 | =item IO | |
297 | ||
298 | load various IO modules | |
299 | ||
300 | =item IO::File | |
301 | ||
302 | supply object methods for filehandles | |
303 | ||
304 | =item IO::Handle | |
305 | ||
306 | supply object methods for I/O handles | |
307 | ||
308 | =item IO::Pipe | |
309 | ||
310 | supply object methods for pipes | |
311 | ||
312 | =item IO::Seekable | |
313 | ||
314 | supply seek based methods for I/O objects | |
315 | ||
316 | =item IO::Select | |
317 | ||
318 | OO interface to the select system call | |
319 | ||
320 | =item IO::Socket | |
321 | ||
322 | object interface to socket communications | |
323 | ||
324 | =item IPC::Open2 | |
325 | ||
326 | open a process for both reading and writing | |
327 | ||
328 | =item IPC::Open3 | |
329 | ||
330 | open a process for reading, writing, and error handling | |
331 | ||
332 | =item Math::BigFloat | |
333 | ||
334 | arbitrary length float math package | |
335 | ||
336 | =item Math::BigInt | |
337 | ||
338 | arbitrary size integer math package | |
339 | ||
340 | =item Math::Complex | |
341 | ||
342 | complex numbers and associated mathematical functions | |
343 | ||
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344 | =item Math::Trig |
345 | ||
346 | simple interface to parts of Math::Complex for those who | |
347 | need trigonometric functions only for real numbers | |
348 | ||
f102b883 TC |
349 | =item NDBM_File |
350 | ||
351 | tied access to ndbm files | |
352 | ||
353 | =item Net::Ping | |
354 | ||
355 | Hello, anybody home? | |
356 | ||
357 | =item Net::hostent | |
358 | ||
359 | by-name interface to Perl's builtin gethost*() functions | |
360 | ||
361 | =item Net::netent | |
362 | ||
363 | by-name interface to Perl's builtin getnet*() functions | |
364 | ||
365 | =item Net::protoent | |
366 | ||
367 | by-name interface to Perl's builtin getproto*() functions | |
368 | ||
369 | =item Net::servent | |
370 | ||
371 | by-name interface to Perl's builtin getserv*() functions | |
372 | ||
373 | =item Opcode | |
374 | ||
5a964f20 | 375 | disable named opcodes when compiling or running Perl code |
f102b883 TC |
376 | |
377 | =item Pod::Text | |
378 | ||
379 | convert POD data to formatted ASCII text | |
380 | ||
381 | =item POSIX | |
382 | ||
383 | interface to IEEE Standard 1003.1 | |
384 | ||
385 | =item SDBM_File | |
386 | ||
387 | tied access to sdbm files | |
388 | ||
389 | =item Safe | |
390 | ||
391 | compile and execute code in restricted compartments | |
392 | ||
393 | =item Search::Dict | |
394 | ||
395 | search for key in dictionary file | |
396 | ||
397 | =item SelectSaver | |
398 | ||
399 | save and restore selected file handle | |
400 | ||
401 | =item SelfLoader | |
402 | ||
403 | load functions only on demand | |
404 | ||
405 | =item Shell | |
406 | ||
5a964f20 | 407 | run shell commands transparently within Perl |
f102b883 TC |
408 | |
409 | =item Socket | |
410 | ||
411 | load the C socket.h defines and structure manipulators | |
412 | ||
413 | =item Symbol | |
414 | ||
415 | manipulate Perl symbols and their names | |
416 | ||
417 | =item Sys::Hostname | |
418 | ||
419 | try every conceivable way to get hostname | |
420 | ||
421 | =item Sys::Syslog | |
422 | ||
423 | interface to the Unix syslog(3) calls | |
424 | ||
425 | =item Term::Cap | |
426 | ||
427 | termcap interface | |
428 | ||
429 | =item Term::Complete | |
430 | ||
431 | word completion module | |
432 | ||
433 | =item Term::ReadLine | |
434 | ||
435 | interface to various C<readline> packages | |
436 | ||
437 | =item Test::Harness | |
438 | ||
5a964f20 | 439 | run Perl standard test scripts with statistics |
f102b883 TC |
440 | |
441 | =item Text::Abbrev | |
442 | ||
443 | create an abbreviation table from a list | |
444 | ||
445 | =item Text::ParseWords | |
446 | ||
447 | parse text into an array of tokens | |
448 | ||
449 | =item Text::Soundex | |
450 | ||
451 | implementation of the Soundex Algorithm as described by Knuth | |
452 | ||
453 | =item Text::Tabs | |
454 | ||
455 | expand and unexpand tabs per the Unix expand(1) and unexpand(1) | |
456 | ||
457 | =item Text::Wrap | |
458 | ||
459 | line wrapping to form simple paragraphs | |
460 | ||
461 | =item Tie::Hash | |
462 | ||
463 | base class definitions for tied hashes | |
464 | ||
465 | =item Tie::RefHash | |
466 | ||
467 | base class definitions for tied hashes with references as keys | |
468 | ||
469 | =item Tie::Scalar | |
470 | ||
471 | base class definitions for tied scalars | |
472 | ||
473 | =item Tie::SubstrHash | |
474 | ||
475 | fixed-table-size, fixed-key-length hashing | |
476 | ||
477 | =item Time::Local | |
478 | ||
479 | efficiently compute time from local and GMT time | |
480 | ||
481 | =item Time::gmtime | |
482 | ||
483 | by-name interface to Perl's builtin gmtime() function | |
484 | ||
485 | =item Time::localtime | |
486 | ||
487 | by-name interface to Perl's builtin localtime() function | |
488 | ||
489 | =item Time::tm | |
490 | ||
491 | internal object used by Time::gmtime and Time::localtime | |
492 | ||
493 | =item UNIVERSAL | |
494 | ||
495 | base class for ALL classes (blessed references) | |
496 | ||
497 | =item User::grent | |
498 | ||
499 | by-name interface to Perl's builtin getgr*() functions | |
500 | ||
501 | =item User::pwent | |
502 | ||
503 | by-name interface to Perl's builtin getpw*() functions | |
504 | ||
505 | =back | |
506 | ||
507 | To find out I<all> the modules installed on your system, including | |
508 | those without documentation or outside the standard release, do this: | |
509 | ||
5a964f20 | 510 | % find `perl -e 'print "@INC"'` -name '*.pm' -print |
f102b883 TC |
511 | |
512 | They should all have their own documentation installed and accessible via | |
513 | your system man(1) command. If that fails, try the I<perldoc> program. | |
514 | ||
515 | =head2 Extension Modules | |
516 | ||
517 | Extension modules are written in C (or a mix of Perl and C) and may be | |
518 | statically linked or in general are | |
519 | dynamically loaded into Perl if and when you need them. Supported | |
520 | extension modules include the Socket, Fcntl, and POSIX modules. | |
521 | ||
522 | Many popular C extension modules do not come bundled (at least, not | |
523 | completely) due to their sizes, volatility, or simply lack of time for | |
524 | adequate testing and configuration across the multitude of platforms on | |
525 | which Perl was beta-tested. You are encouraged to look for them in | |
526 | archie(1L), the Perl FAQ or Meta-FAQ, the WWW page, and even with their | |
527 | authors before randomly posting asking for their present condition and | |
528 | disposition. | |
529 | ||
530 | =head1 CPAN | |
531 | ||
532 | CPAN stands for the Comprehensive Perl Archive Network. This is a globally | |
533 | replicated collection of all known Perl materials, including hundreds | |
534 | of unbundled modules. Here are the major categories of modules: | |
535 | ||
536 | =over | |
537 | ||
538 | =item * | |
539 | Language Extensions and Documentation Tools | |
540 | ||
541 | =item * | |
542 | Development Support | |
543 | ||
544 | =item * | |
545 | Operating System Interfaces | |
546 | ||
547 | =item * | |
548 | Networking, Device Control (modems) and InterProcess Communication | |
549 | ||
550 | =item * | |
551 | Data Types and Data Type Utilities | |
552 | ||
553 | =item * | |
554 | Database Interfaces | |
555 | ||
556 | =item * | |
557 | User Interfaces | |
558 | ||
559 | =item * | |
560 | Interfaces to / Emulations of Other Programming Languages | |
561 | ||
562 | =item * | |
563 | File Names, File Systems and File Locking (see also File Handles) | |
564 | ||
565 | =item * | |
566 | String Processing, Language Text Processing, Parsing, and Searching | |
567 | ||
568 | =item * | |
569 | Option, Argument, Parameter, and Configuration File Processing | |
570 | ||
571 | =item * | |
572 | Internationalization and Locale | |
573 | ||
574 | =item * | |
575 | Authentication, Security, and Encryption | |
576 | ||
577 | =item * | |
578 | World Wide Web, HTML, HTTP, CGI, MIME | |
579 | ||
580 | =item * | |
581 | Server and Daemon Utilities | |
582 | ||
583 | =item * | |
584 | Archiving and Compression | |
585 | ||
586 | =item * | |
587 | Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing | |
588 | ||
589 | =item * | |
590 | Mail and Usenet News | |
591 | ||
592 | =item * | |
593 | Control Flow Utilities (callbacks and exceptions etc) | |
594 | ||
595 | =item * | |
596 | File Handle and Input/Output Stream Utilities | |
597 | ||
598 | =item * | |
599 | Miscellaneous Modules | |
600 | ||
601 | =back | |
602 | ||
603 | The registered CPAN sites as of this writing include the following. | |
604 | You should try to choose one close to you: | |
605 | ||
606 | =over | |
607 | ||
608 | =item * | |
609 | Africa | |
610 | ||
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611 | South Africa ftp://ftp.is.co.za/programming/perl/CPAN/ |
612 | ftp://ftpza.co.za/pub/mirrors/cpan/ | |
f102b883 TC |
613 | |
614 | =item * | |
615 | Asia | |
616 | ||
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617 | Armenia ftp://sunsite.aua.am/pub/CPAN/ |
618 | China ftp://freesoft.cei.gov.cn/pub/languages/perl/CPAN/ | |
619 | Hong Kong ftp://ftp.hkstar.com/pub/CPAN/ | |
620 | Israel ftp://bioinfo.weizmann.ac.il/pub/software/perl/CPAN/ | |
621 | Japan ftp://ftp.dti.ad.jp/pub/lang/CPAN/ | |
622 | ftp://ftp.jaist.ac.jp/pub/lang/perl/CPAN/ | |
623 | ftp://ftp.lab.kdd.co.jp/lang/perl/CPAN/ | |
624 | ftp://ftp.meisei-u.ac.jp/pub/CPAN/ | |
625 | ftp://mirror.nucba.ac.jp/mirror/Perl/ | |
626 | Singapore ftp://ftp.nus.edu.sg/pub/unix/perl/CPAN/ | |
627 | South Korea ftp://ftp.bora.net/pub/CPAN/ | |
628 | ftp://ftp.nuri.net/pub/CPAN/ | |
629 | Taiwan ftp://ftp.wownet.net/pub2/PERL/ | |
630 | ftp://ftp1.sinica.edu.tw/pub1/perl/CPAN/ | |
631 | Thailand ftp://ftp.cs.riubon.ac.th/pub/mirrors/CPAN/ | |
632 | ftp://ftp.nectec.or.th/pub/mirrors/CPAN/ | |
f102b883 TC |
633 | |
634 | =item * | |
635 | Australasia | |
636 | ||
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637 | Australia ftp://cpan.topend.com.au/pub/CPAN/ |
638 | ftp://ftp.labyrinth.net.au/pub/perl/CPAN/ | |
639 | ftp://ftp.sage-au.org.au/pub/compilers/perl/CPAN/ | |
640 | ftp://mirror.aarnet.edu.au/pub/perl/CPAN/ | |
641 | New Zealand ftp://ftp.auckland.ac.nz/pub/perl/CPAN/ | |
642 | ftp://sunsite.net.nz/pub/languages/perl/CPAN/ | |
643 | ||
644 | =item * | |
645 | Central America | |
646 | ||
647 | Costa Rica ftp://ftp.ucr.ac.cr/pub/Unix/CPAN/ | |
f102b883 TC |
648 | |
649 | =item * | |
650 | Europe | |
651 | ||
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652 | Austria ftp://ftp.tuwien.ac.at/pub/languages/perl/CPAN/ |
653 | Belgium ftp://ftp.kulnet.kuleuven.ac.be/pub/mirror/CPAN/ | |
654 | Bulgaria ftp://ftp.ntrl.net/pub/mirrors/CPAN/ | |
655 | Croatia ftp://ftp.linux.hr/pub/CPAN/ | |
656 | Czech Republic ftp://ftp.fi.muni.cz/pub/perl/ | |
657 | ftp://sunsite.mff.cuni.cz/Languages/Perl/CPAN/ | |
658 | Denmark ftp://sunsite.auc.dk/pub/languages/perl/CPAN/ | |
659 | Estonia ftp://ftp.ut.ee/pub/languages/perl/CPAN/ | |
660 | Finland ftp://ftp.funet.fi/pub/languages/perl/CPAN/ | |
661 | France ftp://ftp.lip6.fr/pub/perl/CPAN/ | |
662 | ftp://ftp.oleane.net/pub/mirrors/CPAN/ | |
663 | ftp://ftp.pasteur.fr/pub/computing/CPAN/ | |
664 | Germany ftp://ftp.archive.de.uu.net/pub/CPAN/ | |
665 | ftp://ftp.gmd.de/packages/CPAN/ | |
666 | ftp://ftp.gwdg.de/pub/languages/perl/CPAN/ | |
667 | ftp://ftp.leo.org/pub/comp/programming/languages/script/perl/CPAN/ | |
668 | ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/ | |
669 | ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/ | |
670 | ftp://ftp.uni-erlangen.de/pub/source/CPAN/ | |
671 | ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/ | |
672 | Greece ftp://ftp.ntua.gr/pub/lang/perl/ | |
673 | Hungary ftp://ftp.kfki.hu/pub/packages/perl/CPAN/ | |
674 | Ireland ftp://sunsite.compapp.dcu.ie/pub/perl/ | |
675 | Italy ftp://cis.uniRoma2.it/CPAN/ | |
676 | ftp://ftp.flashnet.it/pub/CPAN/ | |
677 | ftp://ftp.unipi.it/pub/mirror/perl/CPAN/ | |
678 | Netherlands ftp://ftp.cs.uu.nl/mirror/CPAN/ | |
679 | ftp://ftp.nluug.nl/pub/languages/perl/CPAN/ | |
680 | Norway ftp://ftp.uit.no/pub/languages/perl/cpan/ | |
681 | ftp://sunsite.uio.no/pub/languages/perl/CPAN/ | |
682 | Poland ftp://ftp.man.szczecin.pl/pub/perl/CPAN/ | |
683 | ftp://ftp.man.torun.pl/pub/doc/CPAN/ | |
684 | ftp://ftp.pk.edu.pl/pub/lang/perl/CPAN/ | |
685 | ftp://sunsite.icm.edu.pl/pub/CPAN/ | |
686 | Portugal ftp://ftp.ci.uminho.pt/pub/mirrors/cpan/ | |
687 | ftp://ftp.ua.pt/pub/CPAN/ | |
688 | Romania ftp://ftp.dntis.ro/pub/mirrors/perl-cpan/ | |
689 | ftp://ftp.dnttm.ro/pub/CPAN/ | |
690 | Russia ftp://cpan.npi.msu.su/CPAN/ | |
691 | ftp://ftp.sai.msu.su/pub/lang/perl/CPAN/ | |
692 | Slovakia ftp://ftp.entry.sk/pub/languages/perl/CPAN/ | |
693 | Slovenia ftp://ftp.arnes.si/software/perl/CPAN/ | |
694 | Spain ftp://ftp.etse.urv.es/pub/perl/ | |
695 | ftp://ftp.rediris.es/mirror/CPAN/ | |
696 | Sweden ftp://ftp.sunet.se/pub/lang/perl/CPAN/ | |
697 | Switzerland ftp://sunsite.cnlab-switch.ch/mirror/CPAN/ | |
698 | Turkey ftp://sunsite.bilkent.edu.tr/pub/languages/CPAN/ | |
699 | United Kingdom ftp://ftp.demon.co.uk/pub/mirrors/perl/CPAN/ | |
700 | ftp://ftp.flirble.org/pub/languages/perl/CPAN/ | |
701 | ftp://ftp.plig.org/pub/CPAN/ | |
702 | ftp://sunsite.doc.ic.ac.uk/packages/CPAN/ | |
703 | ftp://unix.hensa.ac.uk/mirrors/perl-CPAN/ | |
f102b883 TC |
704 | |
705 | =item * | |
706 | North America | |
707 | ||
be94a901 GS |
708 | Alberta ftp://sunsite.ualberta.ca/pub/Mirror/CPAN/ |
709 | California ftp://ftp.cdrom.com/pub/perl/CPAN/ | |
710 | ftp://ftp.digital.com/pub/plan/perl/CPAN/ | |
711 | Colorado ftp://ftp.cs.colorado.edu/pub/perl/CPAN/ | |
712 | Florida ftp://ftp.cise.ufl.edu/pub/perl/CPAN/ | |
713 | Illinois ftp://uiarchive.uiuc.edu/pub/lang/perl/CPAN/ | |
714 | Indiana ftp://csociety-ftp.ecn.purdue.edu/pub/CPAN/ | |
715 | ftp://ftp.uwsg.indiana.edu/pub/perl/CPAN/ | |
716 | Manitoba ftp://theory.uwinnipeg.ca/pub/CPAN/ | |
717 | Massachusetts ftp://ftp.ccs.neu.edu/net/mirrors/ftp.funet.fi/pub/languages/perl/CPAN/ | |
718 | ftp://ftp.iguide.com/pub/mirrors/packages/perl/CPAN/ | |
719 | Mexico D.F. ftp://ftp.msg.com.mx/pub/CPAN/ | |
720 | New York ftp://ftp.rge.com/pub/languages/perl/ | |
721 | North Carolina ftp://ftp.duke.edu/pub/perl/ | |
722 | Oklahoma ftp://ftp.ou.edu/mirrors/CPAN/ | |
723 | Ontario ftp://ftp.crc.ca/pub/packages/perl/CPAN/ | |
724 | Oregon ftp://ftp.orst.edu/pub/packages/CPAN/ | |
725 | Pennsylvania ftp://ftp.epix.net/pub/languages/perl/ | |
726 | Texas ftp://ftp.sedl.org/pub/mirrors/CPAN/ | |
727 | Utah ftp://mirror.xmission.com/CPAN/ | |
728 | Virginia ftp://ftp.perl.org/pub/perl/CPAN/ | |
729 | ftp://ruff.cs.jmu.edu/pub/CPAN/ | |
730 | Washington ftp://ftp.spu.edu/pub/CPAN/ | |
f102b883 TC |
731 | |
732 | =item * | |
733 | South America | |
734 | ||
be94a901 GS |
735 | Brazil ftp://cpan.if.usp.br/pub/mirror/CPAN/ |
736 | Chile ftp://ftp.ing.puc.cl/pub/unix/perl/CPAN/ | |
737 | ftp://sunsite.dcc.uchile.cl/pub/Lang/perl/CPAN/ | |
f102b883 TC |
738 | |
739 | =back | |
740 | ||
741 | For an up-to-date listing of CPAN sites, | |
742 | see F<http://www.perl.com/perl/CPAN> or F<ftp://ftp.perl.com/perl/>. | |
743 | ||
744 | =head1 Modules: Creation, Use, and Abuse | |
745 | ||
746 | (The following section is borrowed directly from Tim Bunce's modules | |
747 | file, available at your nearest CPAN site.) | |
748 | ||
749 | Perl implements a class using a package, but the presence of a | |
750 | package doesn't imply the presence of a class. A package is just a | |
751 | namespace. A class is a package that provides subroutines that can be | |
752 | used as methods. A method is just a subroutine that expects, as its | |
753 | first argument, either the name of a package (for "static" methods), | |
754 | or a reference to something (for "virtual" methods). | |
755 | ||
756 | A module is a file that (by convention) provides a class of the same | |
757 | name (sans the .pm), plus an import method in that class that can be | |
758 | called to fetch exported symbols. This module may implement some of | |
759 | its methods by loading dynamic C or C++ objects, but that should be | |
760 | totally transparent to the user of the module. Likewise, the module | |
761 | might set up an AUTOLOAD function to slurp in subroutine definitions on | |
762 | demand, but this is also transparent. Only the F<.pm> file is required to | |
763 | exist. See L<perlsub>, L<perltoot>, and L<AutoLoader> for details about | |
764 | the AUTOLOAD mechanism. | |
765 | ||
766 | =head2 Guidelines for Module Creation | |
767 | ||
768 | =over 4 | |
769 | ||
770 | =item Do similar modules already exist in some form? | |
771 | ||
772 | If so, please try to reuse the existing modules either in whole or | |
773 | by inheriting useful features into a new class. If this is not | |
774 | practical try to get together with the module authors to work on | |
775 | extending or enhancing the functionality of the existing modules. | |
776 | A perfect example is the plethora of packages in perl4 for dealing | |
777 | with command line options. | |
778 | ||
779 | If you are writing a module to expand an already existing set of | |
780 | modules, please coordinate with the author of the package. It | |
781 | helps if you follow the same naming scheme and module interaction | |
782 | scheme as the original author. | |
783 | ||
784 | =item Try to design the new module to be easy to extend and reuse. | |
785 | ||
786 | Use blessed references. Use the two argument form of bless to bless | |
787 | into the class name given as the first parameter of the constructor, | |
788 | e.g.,: | |
789 | ||
790 | sub new { | |
791 | my $class = shift; | |
792 | return bless {}, $class; | |
793 | } | |
794 | ||
795 | or even this if you'd like it to be used as either a static | |
796 | or a virtual method. | |
797 | ||
798 | sub new { | |
799 | my $self = shift; | |
800 | my $class = ref($self) || $self; | |
801 | return bless {}, $class; | |
802 | } | |
803 | ||
804 | Pass arrays as references so more parameters can be added later | |
805 | (it's also faster). Convert functions into methods where | |
806 | appropriate. Split large methods into smaller more flexible ones. | |
807 | Inherit methods from other modules if appropriate. | |
808 | ||
809 | Avoid class name tests like: C<die "Invalid" unless ref $ref eq 'FOO'>. | |
810 | Generally you can delete the "C<eq 'FOO'>" part with no harm at all. | |
811 | Let the objects look after themselves! Generally, avoid hard-wired | |
812 | class names as far as possible. | |
813 | ||
814 | Avoid C<$r-E<gt>Class::func()> where using C<@ISA=qw(... Class ...)> and | |
815 | C<$r-E<gt>func()> would work (see L<perlbot> for more details). | |
816 | ||
817 | Use autosplit so little used or newly added functions won't be a | |
5a964f20 | 818 | burden to programs that don't use them. Add test functions to |
f102b883 TC |
819 | the module after __END__ either using AutoSplit or by saying: |
820 | ||
821 | eval join('',<main::DATA>) || die $@ unless caller(); | |
822 | ||
823 | Does your module pass the 'empty subclass' test? If you say | |
824 | "C<@SUBCLASS::ISA = qw(YOURCLASS);>" your applications should be able | |
825 | to use SUBCLASS in exactly the same way as YOURCLASS. For example, | |
826 | does your application still work if you change: C<$obj = new YOURCLASS;> | |
827 | into: C<$obj = new SUBCLASS;> ? | |
828 | ||
829 | Avoid keeping any state information in your packages. It makes it | |
830 | difficult for multiple other packages to use yours. Keep state | |
831 | information in objects. | |
832 | ||
833 | Always use B<-w>. Try to C<use strict;> (or C<use strict qw(...);>). | |
834 | Remember that you can add C<no strict qw(...);> to individual blocks | |
5a964f20 | 835 | of code that need less strictness. Always use B<-w>. Always use B<-w>! |
f102b883 TC |
836 | Follow the guidelines in the perlstyle(1) manual. |
837 | ||
838 | =item Some simple style guidelines | |
839 | ||
5a964f20 | 840 | The perlstyle manual supplied with Perl has many helpful points. |
f102b883 TC |
841 | |
842 | Coding style is a matter of personal taste. Many people evolve their | |
843 | style over several years as they learn what helps them write and | |
844 | maintain good code. Here's one set of assorted suggestions that | |
845 | seem to be widely used by experienced developers: | |
846 | ||
847 | Use underscores to separate words. It is generally easier to read | |
848 | $var_names_like_this than $VarNamesLikeThis, especially for | |
849 | non-native speakers of English. It's also a simple rule that works | |
850 | consistently with VAR_NAMES_LIKE_THIS. | |
851 | ||
852 | Package/Module names are an exception to this rule. Perl informally | |
853 | reserves lowercase module names for 'pragma' modules like integer | |
854 | and strict. Other modules normally begin with a capital letter and | |
855 | use mixed case with no underscores (need to be short and portable). | |
856 | ||
857 | You may find it helpful to use letter case to indicate the scope | |
858 | or nature of a variable. For example: | |
859 | ||
5a964f20 | 860 | $ALL_CAPS_HERE constants only (beware clashes with Perl vars) |
f102b883 TC |
861 | $Some_Caps_Here package-wide global/static |
862 | $no_caps_here function scope my() or local() variables | |
863 | ||
864 | Function and method names seem to work best as all lowercase. | |
865 | e.g., C<$obj-E<gt>as_string()>. | |
866 | ||
867 | You can use a leading underscore to indicate that a variable or | |
868 | function should not be used outside the package that defined it. | |
869 | ||
870 | =item Select what to export. | |
871 | ||
872 | Do NOT export method names! | |
873 | ||
874 | Do NOT export anything else by default without a good reason! | |
875 | ||
876 | Exports pollute the namespace of the module user. If you must | |
877 | export try to use @EXPORT_OK in preference to @EXPORT and avoid | |
878 | short or common names to reduce the risk of name clashes. | |
879 | ||
880 | Generally anything not exported is still accessible from outside the | |
881 | module using the ModuleName::item_name (or C<$blessed_ref-E<gt>method>) | |
882 | syntax. By convention you can use a leading underscore on names to | |
883 | indicate informally that they are 'internal' and not for public use. | |
884 | ||
885 | (It is actually possible to get private functions by saying: | |
886 | C<my $subref = sub { ... }; &$subref;>. But there's no way to call that | |
887 | directly as a method, because a method must have a name in the symbol | |
888 | table.) | |
889 | ||
890 | As a general rule, if the module is trying to be object oriented | |
891 | then export nothing. If it's just a collection of functions then | |
892 | @EXPORT_OK anything but use @EXPORT with caution. | |
893 | ||
894 | =item Select a name for the module. | |
895 | ||
896 | This name should be as descriptive, accurate, and complete as | |
897 | possible. Avoid any risk of ambiguity. Always try to use two or | |
898 | more whole words. Generally the name should reflect what is special | |
899 | about what the module does rather than how it does it. Please use | |
900 | nested module names to group informally or categorize a module. | |
901 | There should be a very good reason for a module not to have a nested name. | |
902 | Module names should begin with a capital letter. | |
903 | ||
904 | Having 57 modules all called Sort will not make life easy for anyone | |
905 | (though having 23 called Sort::Quick is only marginally better :-). | |
906 | Imagine someone trying to install your module alongside many others. | |
907 | If in any doubt ask for suggestions in comp.lang.perl.misc. | |
908 | ||
909 | If you are developing a suite of related modules/classes it's good | |
910 | practice to use nested classes with a common prefix as this will | |
911 | avoid namespace clashes. For example: Xyz::Control, Xyz::View, | |
912 | Xyz::Model etc. Use the modules in this list as a naming guide. | |
913 | ||
914 | If adding a new module to a set, follow the original author's | |
915 | standards for naming modules and the interface to methods in | |
916 | those modules. | |
917 | ||
918 | To be portable each component of a module name should be limited to | |
919 | 11 characters. If it might be used on MS-DOS then try to ensure each is | |
920 | unique in the first 8 characters. Nested modules make this easier. | |
921 | ||
922 | =item Have you got it right? | |
923 | ||
924 | How do you know that you've made the right decisions? Have you | |
925 | picked an interface design that will cause problems later? Have | |
926 | you picked the most appropriate name? Do you have any questions? | |
927 | ||
928 | The best way to know for sure, and pick up many helpful suggestions, | |
929 | is to ask someone who knows. Comp.lang.perl.misc is read by just about | |
930 | all the people who develop modules and it's the best place to ask. | |
931 | ||
932 | All you need to do is post a short summary of the module, its | |
933 | purpose and interfaces. A few lines on each of the main methods is | |
934 | probably enough. (If you post the whole module it might be ignored | |
935 | by busy people - generally the very people you want to read it!) | |
936 | ||
937 | Don't worry about posting if you can't say when the module will be | |
938 | ready - just say so in the message. It might be worth inviting | |
939 | others to help you, they may be able to complete it for you! | |
940 | ||
941 | =item README and other Additional Files. | |
942 | ||
943 | It's well known that software developers usually fully document the | |
944 | software they write. If, however, the world is in urgent need of | |
945 | your software and there is not enough time to write the full | |
946 | documentation please at least provide a README file containing: | |
947 | ||
948 | =over 10 | |
949 | ||
950 | =item * | |
951 | A description of the module/package/extension etc. | |
952 | ||
953 | =item * | |
954 | A copyright notice - see below. | |
955 | ||
956 | =item * | |
957 | Prerequisites - what else you may need to have. | |
958 | ||
959 | =item * | |
960 | How to build it - possible changes to Makefile.PL etc. | |
961 | ||
962 | =item * | |
963 | How to install it. | |
964 | ||
965 | =item * | |
966 | Recent changes in this release, especially incompatibilities | |
967 | ||
968 | =item * | |
969 | Changes / enhancements you plan to make in the future. | |
970 | ||
971 | =back | |
972 | ||
973 | If the README file seems to be getting too large you may wish to | |
974 | split out some of the sections into separate files: INSTALL, | |
975 | Copying, ToDo etc. | |
976 | ||
977 | =over 4 | |
978 | ||
979 | =item Adding a Copyright Notice. | |
980 | ||
981 | How you choose to license your work is a personal decision. | |
982 | The general mechanism is to assert your Copyright and then make | |
983 | a declaration of how others may copy/use/modify your work. | |
984 | ||
985 | Perl, for example, is supplied with two types of licence: The GNU | |
986 | GPL and The Artistic Licence (see the files README, Copying, and | |
987 | Artistic). Larry has good reasons for NOT just using the GNU GPL. | |
988 | ||
989 | My personal recommendation, out of respect for Larry, Perl, and the | |
5a964f20 | 990 | Perl community at large is to state something simply like: |
f102b883 TC |
991 | |
992 | Copyright (c) 1995 Your Name. All rights reserved. | |
993 | This program is free software; you can redistribute it and/or | |
994 | modify it under the same terms as Perl itself. | |
995 | ||
996 | This statement should at least appear in the README file. You may | |
997 | also wish to include it in a Copying file and your source files. | |
998 | Remember to include the other words in addition to the Copyright. | |
999 | ||
1000 | =item Give the module a version/issue/release number. | |
1001 | ||
1002 | To be fully compatible with the Exporter and MakeMaker modules you | |
1003 | should store your module's version number in a non-my package | |
1004 | variable called $VERSION. This should be a floating point | |
1005 | number with at least two digits after the decimal (i.e., hundredths, | |
1006 | e.g, C<$VERSION = "0.01">). Don't use a "1.3.2" style version. | |
1007 | See Exporter.pm in Perl5.001m or later for details. | |
1008 | ||
1009 | It may be handy to add a function or method to retrieve the number. | |
1010 | Use the number in announcements and archive file names when | |
1011 | releasing the module (ModuleName-1.02.tar.Z). | |
1012 | See perldoc ExtUtils::MakeMaker.pm for details. | |
1013 | ||
1014 | =item How to release and distribute a module. | |
1015 | ||
1016 | It's good idea to post an announcement of the availability of your | |
1017 | module (or the module itself if small) to the comp.lang.perl.announce | |
1018 | Usenet newsgroup. This will at least ensure very wide once-off | |
1019 | distribution. | |
1020 | ||
1021 | If possible you should place the module into a major ftp archive and | |
1022 | include details of its location in your announcement. | |
1023 | ||
1024 | Some notes about ftp archives: Please use a long descriptive file | |
5a964f20 | 1025 | name that includes the version number. Most incoming directories |
f102b883 TC |
1026 | will not be readable/listable, i.e., you won't be able to see your |
1027 | file after uploading it. Remember to send your email notification | |
1028 | message as soon as possible after uploading else your file may get | |
1029 | deleted automatically. Allow time for the file to be processed | |
1030 | and/or check the file has been processed before announcing its | |
1031 | location. | |
1032 | ||
1033 | FTP Archives for Perl Modules: | |
1034 | ||
1035 | Follow the instructions and links on | |
1036 | ||
1037 | http://franz.ww.tu-berlin.de/modulelist | |
1038 | ||
1039 | or upload to one of these sites: | |
1040 | ||
1041 | ftp://franz.ww.tu-berlin.de/incoming | |
1042 | ftp://ftp.cis.ufl.edu/incoming | |
1043 | ||
1044 | and notify <F<upload@franz.ww.tu-berlin.de>>. | |
1045 | ||
1046 | By using the WWW interface you can ask the Upload Server to mirror | |
1047 | your modules from your ftp or WWW site into your own directory on | |
1048 | CPAN! | |
1049 | ||
1050 | Please remember to send me an updated entry for the Module list! | |
1051 | ||
1052 | =item Take care when changing a released module. | |
1053 | ||
7b8d334a GS |
1054 | Always strive to remain compatible with previous released versions. |
1055 | Otherwise try to add a mechanism to revert to the | |
f102b883 TC |
1056 | old behaviour if people rely on it. Document incompatible changes. |
1057 | ||
1058 | =back | |
1059 | ||
1060 | =back | |
1061 | ||
1062 | =head2 Guidelines for Converting Perl 4 Library Scripts into Modules | |
1063 | ||
1064 | =over 4 | |
1065 | ||
1066 | =item There is no requirement to convert anything. | |
1067 | ||
1068 | If it ain't broke, don't fix it! Perl 4 library scripts should | |
1069 | continue to work with no problems. You may need to make some minor | |
1070 | changes (like escaping non-array @'s in double quoted strings) but | |
1071 | there is no need to convert a .pl file into a Module for just that. | |
1072 | ||
1073 | =item Consider the implications. | |
1074 | ||
5a964f20 | 1075 | All Perl applications that make use of the script will need to |
f102b883 TC |
1076 | be changed (slightly) if the script is converted into a module. Is |
1077 | it worth it unless you plan to make other changes at the same time? | |
1078 | ||
1079 | =item Make the most of the opportunity. | |
1080 | ||
1081 | If you are going to convert the script to a module you can use the | |
1082 | opportunity to redesign the interface. The 'Guidelines for Module | |
1083 | Creation' above include many of the issues you should consider. | |
1084 | ||
1085 | =item The pl2pm utility will get you started. | |
1086 | ||
1087 | This utility will read *.pl files (given as parameters) and write | |
1088 | corresponding *.pm files. The pl2pm utilities does the following: | |
1089 | ||
1090 | =over 10 | |
1091 | ||
1092 | =item * | |
1093 | Adds the standard Module prologue lines | |
1094 | ||
1095 | =item * | |
1096 | Converts package specifiers from ' to :: | |
1097 | ||
1098 | =item * | |
1099 | Converts die(...) to croak(...) | |
1100 | ||
1101 | =item * | |
1102 | Several other minor changes | |
1103 | ||
1104 | =back | |
1105 | ||
1106 | Being a mechanical process pl2pm is not bullet proof. The converted | |
1107 | code will need careful checking, especially any package statements. | |
1108 | Don't delete the original .pl file till the new .pm one works! | |
1109 | ||
1110 | =back | |
1111 | ||
1112 | =head2 Guidelines for Reusing Application Code | |
1113 | ||
1114 | =over 4 | |
1115 | ||
1116 | =item Complete applications rarely belong in the Perl Module Library. | |
1117 | ||
5a964f20 | 1118 | =item Many applications contain some Perl code that could be reused. |
f102b883 TC |
1119 | |
1120 | Help save the world! Share your code in a form that makes it easy | |
1121 | to reuse. | |
1122 | ||
1123 | =item Break-out the reusable code into one or more separate module files. | |
1124 | ||
1125 | =item Take the opportunity to reconsider and redesign the interfaces. | |
1126 | ||
1127 | =item In some cases the 'application' can then be reduced to a small | |
1128 | ||
1129 | fragment of code built on top of the reusable modules. In these cases | |
1130 | the application could invoked as: | |
1131 | ||
5a964f20 | 1132 | % perl -e 'use Module::Name; method(@ARGV)' ... |
f102b883 | 1133 | or |
5a964f20 | 1134 | % perl -mModule::Name ... (in perl5.002 or higher) |
f102b883 TC |
1135 | |
1136 | =back | |
1137 | ||
1138 | =head1 NOTE | |
1139 | ||
1140 | Perl does not enforce private and public parts of its modules as you may | |
1141 | have been used to in other languages like C++, Ada, or Modula-17. Perl | |
1142 | doesn't have an infatuation with enforced privacy. It would prefer | |
1143 | that you stayed out of its living room because you weren't invited, not | |
1144 | because it has a shotgun. | |
1145 | ||
1146 | The module and its user have a contract, part of which is common law, | |
1147 | and part of which is "written". Part of the common law contract is | |
1148 | that a module doesn't pollute any namespace it wasn't asked to. The | |
1149 | written contract for the module (A.K.A. documentation) may make other | |
1150 | provisions. But then you know when you C<use RedefineTheWorld> that | |
1151 | you're redefining the world and willing to take the consequences. |