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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 | ||
19799a22 GS |
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 TC |
22 | |
23 | =head2 Pragmatic Modules | |
24 | ||
19799a22 GS |
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 TC |
30 | |
31 | no integer; | |
32 | no strict 'refs'; | |
4438c4b7 | 33 | no warnings; |
f102b883 TC |
34 | |
35 | which lasts until the end of that BLOCK. | |
36 | ||
19799a22 GS |
37 | Some pragmas are lexically scoped--typically those that affect the |
38 | C<$^H> hints variable. Others affect the current package instead, | |
77ca0c92 | 39 | like C<use vars> and C<use subs>, which allow you to predeclare a |
19799a22 GS |
40 | variables or subroutines within a particular I<file> rather than |
41 | just a block. Such declarations are effective for the entire file | |
42 | for which they were declared. You cannot rescind them with C<no | |
43 | vars> or C<no subs>. | |
f102b883 TC |
44 | |
45 | The following pragmas are defined (and have their own documentation). | |
46 | ||
47 | =over 12 | |
48 | ||
09bef843 SB |
49 | =item attributes |
50 | ||
9e107c59 | 51 | Get/set subroutine or variable attributes |
09bef843 | 52 | |
19799a22 | 53 | =item attrs |
f102b883 | 54 | |
9e107c59 | 55 | Set/get attributes of a subroutine (deprecated) |
19799a22 GS |
56 | |
57 | =item autouse | |
58 | ||
9e107c59 | 59 | Postpone load of modules until a function is used |
19799a22 GS |
60 | |
61 | =item base | |
62 | ||
63 | Establish IS-A relationship with base class at compile time | |
f102b883 TC |
64 | |
65 | =item blib | |
66 | ||
19799a22 GS |
67 | Use MakeMaker's uninstalled version of a package |
68 | ||
2e1d04bc | 69 | =item bytes |
9e107c59 | 70 | |
2e1d04bc | 71 | Force byte semantics rather than character semantics |
9e107c59 GS |
72 | |
73 | =item charnames | |
74 | ||
75 | Define character names for C<\N{named}> string literal escape. | |
76 | ||
19799a22 GS |
77 | =item constant |
78 | ||
9e107c59 | 79 | Declare constants |
f102b883 TC |
80 | |
81 | =item diagnostics | |
82 | ||
2e1d04bc | 83 | Perl compiler pragma to force verbose warning diagnostics |
19799a22 GS |
84 | |
85 | =item fields | |
86 | ||
2e1d04bc | 87 | Compile-time class fields |
19799a22 GS |
88 | |
89 | =item filetest | |
90 | ||
2e1d04bc | 91 | Control the filetest permission operators |
f102b883 TC |
92 | |
93 | =item integer | |
94 | ||
9e107c59 | 95 | Compute arithmetic in integer instead of double |
f102b883 TC |
96 | |
97 | =item less | |
98 | ||
2e1d04bc | 99 | Request less of something from the compiler |
f102b883 | 100 | |
f102b883 TC |
101 | =item locale |
102 | ||
2e1d04bc JH |
103 | Use and avoid POSIX locales for built-in operations |
104 | ||
105 | =item open | |
106 | ||
107 | Set default disciplines for input and output | |
f102b883 TC |
108 | |
109 | =item ops | |
110 | ||
9e107c59 | 111 | Restrict unsafe operations when compiling |
f102b883 TC |
112 | |
113 | =item overload | |
114 | ||
2e1d04bc | 115 | Package for overloading perl operations |
f102b883 | 116 | |
b3eb6a9b GS |
117 | =item re |
118 | ||
2e1d04bc | 119 | Alter regular expression behaviour |
b3eb6a9b | 120 | |
f102b883 TC |
121 | =item sigtrap |
122 | ||
9e107c59 | 123 | Enable simple signal handling |
f102b883 TC |
124 | |
125 | =item strict | |
126 | ||
9e107c59 | 127 | Restrict unsafe constructs |
f102b883 TC |
128 | |
129 | =item subs | |
130 | ||
2e1d04bc | 131 | Predeclare sub names |
f102b883 | 132 | |
19799a22 | 133 | =item utf8 |
f102b883 | 134 | |
2e1d04bc | 135 | Enable/disable UTF-8 in source code |
f102b883 TC |
136 | |
137 | =item vars | |
138 | ||
2e1d04bc | 139 | Predeclare global variable names (obsolete) |
f102b883 | 140 | |
4438c4b7 | 141 | =item warnings |
0453d815 | 142 | |
9e107c59 | 143 | Control optional warnings |
19799a22 | 144 | |
13a2d996 SP |
145 | =item warnings::register |
146 | ||
147 | Warnings import function | |
148 | ||
f102b883 TC |
149 | =back |
150 | ||
151 | =head2 Standard Modules | |
152 | ||
153 | Standard, bundled modules are all expected to behave in a well-defined | |
154 | manner with respect to namespace pollution because they use the | |
155 | Exporter module. See their own documentation for details. | |
156 | ||
157 | =over 12 | |
158 | ||
159 | =item AnyDBM_File | |
160 | ||
2e1d04bc | 161 | Provide framework for multiple DBMs |
f102b883 TC |
162 | |
163 | =item AutoLoader | |
164 | ||
9e107c59 | 165 | Load subroutines only on demand |
f102b883 TC |
166 | |
167 | =item AutoSplit | |
168 | ||
9e107c59 | 169 | Split a package for autoloading |
f102b883 | 170 | |
19799a22 GS |
171 | =item B |
172 | ||
2e1d04bc | 173 | The Perl Compiler |
19799a22 GS |
174 | |
175 | =item B::Asmdata | |
176 | ||
177 | Autogenerated data about Perl ops, used to generate bytecode | |
178 | ||
179 | =item B::Assembler | |
180 | ||
181 | Assemble Perl bytecode | |
182 | ||
183 | =item B::Bblock | |
184 | ||
185 | Walk basic blocks | |
186 | ||
187 | =item B::Bytecode | |
188 | ||
189 | Perl compiler's bytecode backend | |
190 | ||
191 | =item B::C | |
192 | ||
193 | Perl compiler's C backend | |
194 | ||
195 | =item B::CC | |
196 | ||
197 | Perl compiler's optimized C translation backend | |
198 | ||
199 | =item B::Debug | |
200 | ||
201 | Walk Perl syntax tree, printing debug info about ops | |
202 | ||
203 | =item B::Deparse | |
204 | ||
2e1d04bc | 205 | Perl compiler backend to produce perl code |
19799a22 GS |
206 | |
207 | =item B::Disassembler | |
208 | ||
209 | Disassemble Perl bytecode | |
210 | ||
211 | =item B::Lint | |
212 | ||
2e1d04bc | 213 | Perl lint |
19799a22 GS |
214 | |
215 | =item B::Showlex | |
216 | ||
217 | Show lexical variables used in functions or files | |
218 | ||
219 | =item B::Stackobj | |
220 | ||
221 | Helper module for CC backend | |
222 | ||
13a2d996 SP |
223 | =item B::Stash |
224 | ||
225 | Show what stashes are loaded | |
226 | ||
19799a22 GS |
227 | =item B::Terse |
228 | ||
229 | Walk Perl syntax tree, printing terse info about ops | |
230 | ||
231 | =item B::Xref | |
232 | ||
233 | Generates cross reference reports for Perl programs | |
234 | ||
f102b883 TC |
235 | =item Benchmark |
236 | ||
2e1d04bc | 237 | Benchmark running times of Perl code |
9e107c59 GS |
238 | |
239 | =item ByteLoader | |
240 | ||
2e1d04bc | 241 | Load byte compiled perl code |
f102b883 | 242 | |
19799a22 GS |
243 | =item CGI |
244 | ||
2e1d04bc | 245 | Simple Common Gateway Interface Class |
19799a22 GS |
246 | |
247 | =item CGI::Apache | |
248 | ||
2e1d04bc | 249 | Backward compatibility module for CGI.pm |
19799a22 GS |
250 | |
251 | =item CGI::Carp | |
252 | ||
253 | CGI routines for writing to the HTTPD (or other) error log | |
254 | ||
255 | =item CGI::Cookie | |
256 | ||
257 | Interface to Netscape Cookies | |
258 | ||
259 | =item CGI::Fast | |
260 | ||
261 | CGI Interface for Fast CGI | |
262 | ||
9e107c59 GS |
263 | =item CGI::Pretty |
264 | ||
265 | Module to produce nicely formatted HTML code | |
266 | ||
19799a22 GS |
267 | =item CGI::Push |
268 | ||
269 | Simple Interface to Server Push | |
270 | ||
271 | =item CGI::Switch | |
272 | ||
2e1d04bc | 273 | Backward compatibility module for defunct CGI::Switch |
19799a22 | 274 | |
f102b883 TC |
275 | =item CPAN |
276 | ||
2e1d04bc | 277 | Query, download and build perl modules from CPAN sites |
f102b883 TC |
278 | |
279 | =item CPAN::FirstTime | |
280 | ||
2e1d04bc | 281 | Utility for CPAN::Config file Initialization |
f102b883 TC |
282 | |
283 | =item CPAN::Nox | |
284 | ||
19799a22 | 285 | Wrapper around CPAN.pm without using any XS module |
f102b883 TC |
286 | |
287 | =item Carp | |
288 | ||
2e1d04bc | 289 | Warn of errors (from perspective of caller) |
9e107c59 GS |
290 | |
291 | =item Carp::Heavy | |
292 | ||
293 | Carp guts | |
f102b883 TC |
294 | |
295 | =item Class::Struct | |
296 | ||
9e107c59 | 297 | Declare struct-like datatypes as Perl classes |
f102b883 | 298 | |
f102b883 TC |
299 | =item Cwd |
300 | ||
9e107c59 | 301 | Get pathname of current working directory |
f102b883 | 302 | |
19799a22 GS |
303 | =item DB |
304 | ||
2e1d04bc | 305 | Programmatic interface to the Perl debugging API (draft, subject to |
19799a22 | 306 | |
f102b883 TC |
307 | =item DB_File |
308 | ||
19799a22 GS |
309 | Perl5 access to Berkeley DB version 1.x |
310 | ||
f102b883 TC |
311 | =item Devel::SelfStubber |
312 | ||
9e107c59 | 313 | Generate stubs for a SelfLoading module |
f102b883 TC |
314 | |
315 | =item DirHandle | |
316 | ||
9e107c59 | 317 | Supply object methods for directory handles |
f102b883 | 318 | |
19799a22 GS |
319 | =item Dumpvalue |
320 | ||
2e1d04bc | 321 | Provides screen dump of Perl data. |
f102b883 | 322 | |
13a2d996 SP |
323 | =item Encode |
324 | ||
325 | Character encodings | |
326 | ||
f102b883 TC |
327 | =item English |
328 | ||
2e1d04bc | 329 | Use nice English (or awk) names for ugly punctuation variables |
f102b883 TC |
330 | |
331 | =item Env | |
332 | ||
2e1d04bc | 333 | Perl module that imports environment variables as scalars or arrays |
f102b883 TC |
334 | |
335 | =item Exporter | |
336 | ||
2e1d04bc | 337 | Implements default import method for modules |
9e107c59 GS |
338 | |
339 | =item Exporter::Heavy | |
340 | ||
341 | Exporter guts | |
19799a22 GS |
342 | |
343 | =item ExtUtils::Command | |
344 | ||
2e1d04bc | 345 | Utilities to replace common UNIX commands in Makefiles etc. |
f102b883 TC |
346 | |
347 | =item ExtUtils::Embed | |
348 | ||
2e1d04bc | 349 | Utilities for embedding Perl in C/C++ applications |
f102b883 TC |
350 | |
351 | =item ExtUtils::Install | |
352 | ||
9e107c59 | 353 | Install files from here to there |
f102b883 | 354 | |
19799a22 GS |
355 | =item ExtUtils::Installed |
356 | ||
357 | Inventory management of installed modules | |
358 | ||
f102b883 TC |
359 | =item ExtUtils::Liblist |
360 | ||
9e107c59 GS |
361 | Determine libraries to use and how to use them |
362 | ||
363 | =item ExtUtils::MM_Cygwin | |
364 | ||
2e1d04bc | 365 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
f102b883 TC |
366 | |
367 | =item ExtUtils::MM_OS2 | |
368 | ||
2e1d04bc | 369 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
f102b883 TC |
370 | |
371 | =item ExtUtils::MM_Unix | |
372 | ||
9e107c59 | 373 | Methods used by ExtUtils::MakeMaker |
f102b883 TC |
374 | |
375 | =item ExtUtils::MM_VMS | |
376 | ||
2e1d04bc | 377 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
19799a22 GS |
378 | |
379 | =item ExtUtils::MM_Win32 | |
380 | ||
2e1d04bc | 381 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
f102b883 TC |
382 | |
383 | =item ExtUtils::MakeMaker | |
384 | ||
9e107c59 | 385 | Create an extension Makefile |
f102b883 TC |
386 | |
387 | =item ExtUtils::Manifest | |
388 | ||
9e107c59 | 389 | Utilities to write and check a MANIFEST file |
f102b883 TC |
390 | |
391 | =item ExtUtils::Mkbootstrap | |
392 | ||
9e107c59 | 393 | Make a bootstrap file for use by DynaLoader |
f102b883 TC |
394 | |
395 | =item ExtUtils::Mksymlists | |
396 | ||
9e107c59 | 397 | Write linker options files for dynamic extension |
f102b883 | 398 | |
19799a22 GS |
399 | =item ExtUtils::Packlist |
400 | ||
9e107c59 | 401 | Manage .packlist files |
19799a22 | 402 | |
f102b883 TC |
403 | =item ExtUtils::testlib |
404 | ||
9e107c59 | 405 | Add blib/* directories to @INC |
f102b883 | 406 | |
b6c543e3 IZ |
407 | =item Fatal |
408 | ||
9e107c59 | 409 | Replace functions with equivalents which succeed or die |
b6c543e3 | 410 | |
f102b883 TC |
411 | =item Fcntl |
412 | ||
2e1d04bc | 413 | Load the C Fcntl.h defines |
f102b883 TC |
414 | |
415 | =item File::Basename | |
416 | ||
9e107c59 GS |
417 | Split a pathname into pieces |
418 | ||
419 | =item File::CheckTree | |
420 | ||
421 | Run many filetest checks on a tree | |
f102b883 | 422 | |
f102b883 TC |
423 | =item File::Compare |
424 | ||
19799a22 | 425 | Compare files or filehandles |
f102b883 TC |
426 | |
427 | =item File::Copy | |
428 | ||
19799a22 GS |
429 | Copy files or filehandles |
430 | ||
431 | =item File::DosGlob | |
432 | ||
2e1d04bc | 433 | DOS like globbing and then some |
f102b883 TC |
434 | |
435 | =item File::Find | |
436 | ||
2e1d04bc | 437 | Traverse a file tree |
f102b883 TC |
438 | |
439 | =item File::Path | |
440 | ||
2e1d04bc | 441 | Create or remove directory trees |
f102b883 | 442 | |
f505c983 GS |
443 | =item File::Spec |
444 | ||
9e107c59 | 445 | Portably perform operations on file names |
f505c983 GS |
446 | |
447 | =item File::Spec::Functions | |
448 | ||
9e107c59 | 449 | Portably perform operations on file names |
19799a22 GS |
450 | |
451 | =item File::Spec::Mac | |
452 | ||
453 | File::Spec for MacOS | |
454 | ||
455 | =item File::Spec::OS2 | |
456 | ||
9e107c59 | 457 | Methods for OS/2 file specs |
19799a22 GS |
458 | |
459 | =item File::Spec::Unix | |
460 | ||
9e107c59 | 461 | Methods used by File::Spec |
19799a22 GS |
462 | |
463 | =item File::Spec::VMS | |
464 | ||
9e107c59 | 465 | Methods for VMS file specs |
19799a22 GS |
466 | |
467 | =item File::Spec::Win32 | |
468 | ||
9e107c59 | 469 | Methods for Win32 file specs |
f505c983 | 470 | |
2e1d04bc JH |
471 | =item File::Temp |
472 | ||
473 | Return name and handle of a temporary file safely | |
474 | ||
f102b883 TC |
475 | =item File::stat |
476 | ||
9e107c59 | 477 | By-name interface to Perl's built-in stat() functions |
f102b883 TC |
478 | |
479 | =item FileCache | |
480 | ||
9e107c59 | 481 | Keep more files open than the system permits |
f102b883 TC |
482 | |
483 | =item FileHandle | |
484 | ||
9e107c59 | 485 | Supply object methods for filehandles |
f102b883 TC |
486 | |
487 | =item FindBin | |
488 | ||
2e1d04bc | 489 | Locate directory of original perl script |
f102b883 TC |
490 | |
491 | =item Getopt::Long | |
492 | ||
9e107c59 | 493 | Extended processing of command line options |
f102b883 TC |
494 | |
495 | =item Getopt::Std | |
496 | ||
19799a22 | 497 | Process single-character switches with switch clustering |
f102b883 TC |
498 | |
499 | =item I18N::Collate | |
500 | ||
2e1d04bc | 501 | Compare 8-bit scalar data according to the current locale |
f102b883 TC |
502 | |
503 | =item IO | |
504 | ||
2e1d04bc | 505 | Load various IO modules |
f102b883 TC |
506 | |
507 | =item IPC::Open2 | |
508 | ||
9e107c59 | 509 | Open a process for both reading and writing |
f102b883 TC |
510 | |
511 | =item IPC::Open3 | |
512 | ||
9e107c59 | 513 | Open a process for reading, writing, and error handling |
f102b883 TC |
514 | |
515 | =item Math::BigFloat | |
516 | ||
19799a22 | 517 | Arbitrary length float math package |
f102b883 TC |
518 | |
519 | =item Math::BigInt | |
520 | ||
19799a22 | 521 | Arbitrary size integer math package |
f102b883 TC |
522 | |
523 | =item Math::Complex | |
524 | ||
9e107c59 | 525 | Complex numbers and associated mathematical functions |
f102b883 | 526 | |
404b15a1 CS |
527 | =item Math::Trig |
528 | ||
9e107c59 | 529 | Trigonometric functions |
f102b883 | 530 | |
2e1d04bc JH |
531 | =item NDBM_File |
532 | ||
533 | Tied access to ndbm files | |
534 | ||
f102b883 TC |
535 | =item Net::Ping |
536 | ||
9e107c59 | 537 | Check a remote host for reachability |
f102b883 TC |
538 | |
539 | =item Net::hostent | |
540 | ||
9e107c59 | 541 | By-name interface to Perl's built-in gethost*() functions |
f102b883 TC |
542 | |
543 | =item Net::netent | |
544 | ||
9e107c59 | 545 | By-name interface to Perl's built-in getnet*() functions |
f102b883 TC |
546 | |
547 | =item Net::protoent | |
548 | ||
9e107c59 | 549 | By-name interface to Perl's built-in getproto*() functions |
f102b883 TC |
550 | |
551 | =item Net::servent | |
552 | ||
9e107c59 | 553 | By-name interface to Perl's built-in getserv*() functions |
f102b883 | 554 | |
19799a22 | 555 | =item O |
f102b883 | 556 | |
19799a22 | 557 | Generic interface to Perl Compiler backends |
f102b883 | 558 | |
2e1d04bc | 559 | =item ODBM_File |
f102b883 | 560 | |
2e1d04bc | 561 | Tied access to odbm files |
f102b883 | 562 | |
2e1d04bc | 563 | =item Opcode |
f102b883 | 564 | |
2e1d04bc | 565 | Disable named opcodes when compiling perl code |
19799a22 | 566 | |
9e107c59 GS |
567 | =item Pod::Checker |
568 | ||
569 | Check pod documents for syntax errors | |
570 | ||
2e1d04bc JH |
571 | =item Pod::Find |
572 | ||
573 | Find POD documents in directory trees | |
574 | ||
19799a22 GS |
575 | =item Pod::Html |
576 | ||
9e107c59 GS |
577 | Module to convert pod files to HTML |
578 | ||
579 | =item Pod::InputObjects | |
580 | ||
2e1d04bc | 581 | Objects representing POD input paragraphs, commands, etc. |
9e107c59 | 582 | |
13a2d996 SP |
583 | =item Pod::LaTeX |
584 | ||
585 | Convert Pod data to formatted Latex | |
586 | ||
9e107c59 GS |
587 | =item Pod::Man |
588 | ||
589 | Convert POD data to formatted *roff input | |
590 | ||
2e1d04bc JH |
591 | =item Pod::ParseUtils |
592 | ||
593 | Helpers for POD parsing and conversion | |
594 | ||
9e107c59 GS |
595 | =item Pod::Parser |
596 | ||
597 | Base class for creating POD filters and translators | |
598 | ||
2e1d04bc JH |
599 | =item Pod::Plainer |
600 | ||
601 | Perl extension for converting Pod to old style Pod. | |
602 | ||
9e107c59 GS |
603 | =item Pod::Select |
604 | ||
605 | Extract selected sections of POD from input | |
19799a22 GS |
606 | |
607 | =item Pod::Text | |
608 | ||
9e107c59 GS |
609 | Convert POD data to formatted ASCII text |
610 | ||
611 | =item Pod::Text::Color | |
612 | ||
613 | Convert POD data to formatted color ASCII text | |
614 | ||
2e1d04bc JH |
615 | =item Pod::Text::Termcap |
616 | ||
617 | Convert POD data to ASCII text with format escapes | |
618 | ||
9e107c59 GS |
619 | =item Pod::Usage |
620 | ||
621 | Print a usage message from embedded pod documentation | |
f102b883 TC |
622 | |
623 | =item SDBM_File | |
624 | ||
19799a22 | 625 | Tied access to sdbm files |
f102b883 TC |
626 | |
627 | =item Safe | |
628 | ||
19799a22 | 629 | Compile and execute code in restricted compartments |
f102b883 TC |
630 | |
631 | =item Search::Dict | |
632 | ||
9e107c59 | 633 | Search for key in dictionary file |
f102b883 TC |
634 | |
635 | =item SelectSaver | |
636 | ||
9e107c59 | 637 | Save and restore selected file handle |
f102b883 TC |
638 | |
639 | =item SelfLoader | |
640 | ||
9e107c59 | 641 | Load functions only on demand |
f102b883 TC |
642 | |
643 | =item Shell | |
644 | ||
2e1d04bc | 645 | Run shell commands transparently within perl |
f102b883 TC |
646 | |
647 | =item Socket | |
648 | ||
2e1d04bc | 649 | Load the C socket.h defines and structure manipulators |
f102b883 | 650 | |
13a2d996 SP |
651 | =item Storable |
652 | ||
653 | Persistency for perl data structures | |
654 | ||
f102b883 TC |
655 | =item Symbol |
656 | ||
9e107c59 | 657 | Manipulate Perl symbols and their names |
f102b883 | 658 | |
2e1d04bc | 659 | =item Term::ANSIColor |
f102b883 | 660 | |
2e1d04bc | 661 | Color screen output using ANSI escape sequences |
f102b883 TC |
662 | |
663 | =item Term::Cap | |
664 | ||
2e1d04bc | 665 | Perl termcap interface |
f102b883 TC |
666 | |
667 | =item Term::Complete | |
668 | ||
2e1d04bc | 669 | Perl word completion module |
f102b883 TC |
670 | |
671 | =item Term::ReadLine | |
672 | ||
2e1d04bc | 673 | Perl interface to various C<readline> packages. If |
19799a22 GS |
674 | |
675 | =item Test | |
676 | ||
9e107c59 | 677 | Provides a simple framework for writing test scripts |
f102b883 TC |
678 | |
679 | =item Test::Harness | |
680 | ||
2e1d04bc | 681 | Run perl standard test scripts with statistics |
f102b883 TC |
682 | |
683 | =item Text::Abbrev | |
684 | ||
9e107c59 | 685 | Create an abbreviation table from a list |
f102b883 TC |
686 | |
687 | =item Text::ParseWords | |
688 | ||
2e1d04bc | 689 | Parse text into an array of tokens or array of arrays |
f102b883 TC |
690 | |
691 | =item Text::Soundex | |
692 | ||
2e1d04bc | 693 | Implementation of the Soundex Algorithm as Described by Knuth |
f102b883 TC |
694 | |
695 | =item Text::Wrap | |
696 | ||
9e107c59 | 697 | Line wrapping to form simple paragraphs |
19799a22 GS |
698 | |
699 | =item Tie::Array | |
700 | ||
9e107c59 | 701 | Base class for tied arrays |
19799a22 GS |
702 | |
703 | =item Tie::Handle | |
704 | ||
9e107c59 | 705 | Base class definitions for tied handles |
19799a22 | 706 | |
9e107c59 | 707 | =item Tie::Hash |
f102b883 | 708 | |
9e107c59 | 709 | Base class definitions for tied hashes |
f102b883 TC |
710 | |
711 | =item Tie::RefHash | |
712 | ||
9e107c59 | 713 | Use references as hash keys |
f102b883 | 714 | |
9e107c59 | 715 | =item Tie::Scalar |
f102b883 | 716 | |
9e107c59 | 717 | Base class definitions for tied scalars |
f102b883 TC |
718 | |
719 | =item Tie::SubstrHash | |
720 | ||
19799a22 | 721 | Fixed-table-size, fixed-key-length hashing |
f102b883 TC |
722 | |
723 | =item Time::Local | |
724 | ||
9e107c59 | 725 | Efficiently compute time from local and GMT time |
f102b883 TC |
726 | |
727 | =item Time::gmtime | |
728 | ||
9e107c59 | 729 | By-name interface to Perl's built-in gmtime() function |
f102b883 TC |
730 | |
731 | =item Time::localtime | |
732 | ||
9e107c59 | 733 | By-name interface to Perl's built-in localtime() function |
f102b883 TC |
734 | |
735 | =item Time::tm | |
736 | ||
9e107c59 | 737 | Internal object used by Time::gmtime and Time::localtime |
f102b883 TC |
738 | |
739 | =item UNIVERSAL | |
740 | ||
9e107c59 | 741 | Base class for ALL classes (blessed references) |
f102b883 TC |
742 | |
743 | =item User::grent | |
744 | ||
9e107c59 | 745 | By-name interface to Perl's built-in getgr*() functions |
f102b883 TC |
746 | |
747 | =item User::pwent | |
748 | ||
9e107c59 | 749 | By-name interface to Perl's built-in getpw*() functions |
f102b883 TC |
750 | |
751 | =back | |
752 | ||
19799a22 | 753 | To find out I<all> modules installed on your system, including |
2e1d04bc | 754 | those without documentation or outside the standard release, |
b1866b2d | 755 | just do this: |
f102b883 | 756 | |
5a964f20 | 757 | % find `perl -e 'print "@INC"'` -name '*.pm' -print |
f102b883 | 758 | |
2e1d04bc JH |
759 | They should all have their own documentation installed and accessible |
760 | via your system man(1) command. If you do not have a B<find> | |
19799a22 GS |
761 | program, you can use the Perl B<find2perl> program instead, which |
762 | generates Perl code as output you can run through perl. If you | |
763 | have a B<man> program but it doesn't find your modules, you'll have | |
2e1d04bc JH |
764 | to fix your manpath. See L<perl> for details. If you have no |
765 | system B<man> command, you might try the B<perldoc> program. | |
f102b883 TC |
766 | |
767 | =head2 Extension Modules | |
768 | ||
19799a22 GS |
769 | Extension modules are written in C (or a mix of Perl and C). They |
770 | are usually dynamically loaded into Perl if and when you need them, | |
2e1d04bc | 771 | but may also be be linked in statically. Supported extension modules |
19799a22 | 772 | include Socket, Fcntl, and POSIX. |
f102b883 TC |
773 | |
774 | Many popular C extension modules do not come bundled (at least, not | |
19799a22 GS |
775 | completely) due to their sizes, volatility, or simply lack of time |
776 | for adequate testing and configuration across the multitude of | |
777 | platforms on which Perl was beta-tested. You are encouraged to | |
778 | look for them on CPAN (described below), or using web search engines | |
779 | like Alta Vista or Deja News. | |
f102b883 TC |
780 | |
781 | =head1 CPAN | |
782 | ||
19799a22 GS |
783 | CPAN stands for Comprehensive Perl Archive Network; it's a globally |
784 | replicated trove of Perl materials, including documentation, style | |
2e1d04bc | 785 | guides, tricks and traps, alternate ports to non-Unix systems and |
19799a22 GS |
786 | occasional binary distributions for these. Search engines for |
787 | CPAN can be found at http://cpan.perl.com/ and at | |
788 | http://theory.uwinnipeg.ca/mod_perl/cpan-search.pl . | |
789 | ||
790 | Most importantly, CPAN includes around a thousand unbundled modules, | |
791 | some of which require a C compiler to build. Major categories of | |
792 | modules are: | |
f102b883 | 793 | |
13a2d996 | 794 | =over 4 |
f102b883 TC |
795 | |
796 | =item * | |
797 | Language Extensions and Documentation Tools | |
798 | ||
799 | =item * | |
800 | Development Support | |
801 | ||
802 | =item * | |
803 | Operating System Interfaces | |
804 | ||
805 | =item * | |
806 | Networking, Device Control (modems) and InterProcess Communication | |
807 | ||
808 | =item * | |
809 | Data Types and Data Type Utilities | |
810 | ||
811 | =item * | |
812 | Database Interfaces | |
813 | ||
814 | =item * | |
815 | User Interfaces | |
816 | ||
817 | =item * | |
818 | Interfaces to / Emulations of Other Programming Languages | |
819 | ||
820 | =item * | |
821 | File Names, File Systems and File Locking (see also File Handles) | |
822 | ||
823 | =item * | |
824 | String Processing, Language Text Processing, Parsing, and Searching | |
825 | ||
826 | =item * | |
827 | Option, Argument, Parameter, and Configuration File Processing | |
828 | ||
829 | =item * | |
830 | Internationalization and Locale | |
831 | ||
832 | =item * | |
833 | Authentication, Security, and Encryption | |
834 | ||
835 | =item * | |
836 | World Wide Web, HTML, HTTP, CGI, MIME | |
837 | ||
838 | =item * | |
839 | Server and Daemon Utilities | |
840 | ||
841 | =item * | |
842 | Archiving and Compression | |
843 | ||
844 | =item * | |
845 | Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing | |
846 | ||
847 | =item * | |
848 | Mail and Usenet News | |
849 | ||
850 | =item * | |
851 | Control Flow Utilities (callbacks and exceptions etc) | |
852 | ||
853 | =item * | |
854 | File Handle and Input/Output Stream Utilities | |
855 | ||
856 | =item * | |
857 | Miscellaneous Modules | |
858 | ||
859 | =back | |
860 | ||
19799a22 | 861 | Registered CPAN sites as of this writing include the following. |
f102b883 TC |
862 | You should try to choose one close to you: |
863 | ||
13a2d996 | 864 | =over 4 |
f102b883 | 865 | |
19799a22 | 866 | =item Africa |
f102b883 | 867 | |
0974df93 JH |
868 | South Africa ftp://ftp.is.co.za/programming/perl/CPAN/ |
869 | ftp://ftp.saix.net/pub/CPAN/ | |
870 | ftp://ftp.sun.ac.za/CPAN/ | |
be94a901 | 871 | ftp://ftpza.co.za/pub/mirrors/cpan/ |
f102b883 | 872 | |
6cecdcac | 873 | |
19799a22 | 874 | =item Asia |
f102b883 | 875 | |
0974df93 | 876 | China ftp://freesoft.cei.gov.cn/pub/languages/perl/CPAN/ |
6cecdcac | 877 | Hong Kong ftp://ftp.pacific.net.hk/pub/mirror/CPAN/ |
0974df93 JH |
878 | Indonesia ftp://malone.piksi.itb.ac.id/pub/CPAN/ |
879 | Israel ftp://bioinfo.weizmann.ac.il/pub/software/perl/CPAN/ | |
880 | Japan ftp://ftp.dti.ad.jp/pub/lang/CPAN/ | |
be94a901 GS |
881 | ftp://ftp.jaist.ac.jp/pub/lang/perl/CPAN/ |
882 | ftp://ftp.lab.kdd.co.jp/lang/perl/CPAN/ | |
883 | ftp://ftp.meisei-u.ac.jp/pub/CPAN/ | |
19799a22 | 884 | ftp://ftp.ring.gr.jp/pub/lang/perl/CPAN/ |
be94a901 | 885 | ftp://mirror.nucba.ac.jp/mirror/Perl/ |
6cecdcac | 886 | Saudi-Arabia ftp://ftp.isu.net.sa/pub/CPAN/ |
0974df93 JH |
887 | Singapore ftp://ftp.nus.edu.sg/pub/unix/perl/CPAN/ |
888 | South Korea ftp://ftp.bora.net/pub/CPAN/ | |
889 | ftp://ftp.kornet.net/pub/CPAN/ | |
be94a901 | 890 | ftp://ftp.nuri.net/pub/CPAN/ |
0974df93 JH |
891 | Taiwan ftp://coda.nctu.edu.tw/computer-languages/perl/CPAN/ |
892 | ftp://ftp.ee.ncku.edu.tw/pub3/perl/CPAN/ | |
be94a901 | 893 | ftp://ftp1.sinica.edu.tw/pub1/perl/CPAN/ |
6cecdcac GS |
894 | Thailand ftp://ftp.nectec.or.th/pub/mirrors/CPAN/ |
895 | ||
f102b883 | 896 | |
19799a22 | 897 | =item Australasia |
f102b883 | 898 | |
0974df93 | 899 | Australia ftp://cpan.topend.com.au/pub/CPAN/ |
6cecdcac | 900 | ftp://ftp.labyrinth.net.au/pub/perl-CPAN/ |
be94a901 GS |
901 | ftp://ftp.sage-au.org.au/pub/compilers/perl/CPAN/ |
902 | ftp://mirror.aarnet.edu.au/pub/perl/CPAN/ | |
0974df93 | 903 | New Zealand ftp://ftp.auckland.ac.nz/pub/perl/CPAN/ |
be94a901 GS |
904 | ftp://sunsite.net.nz/pub/languages/perl/CPAN/ |
905 | ||
6cecdcac | 906 | |
0974df93 | 907 | =item Central America |
be94a901 | 908 | |
0974df93 | 909 | Costa Rica ftp://ftp.ucr.ac.cr/pub/Unix/CPAN/ |
f102b883 | 910 | |
6cecdcac | 911 | |
19799a22 | 912 | =item Europe |
f102b883 | 913 | |
0974df93 JH |
914 | Austria ftp://ftp.tuwien.ac.at/pub/languages/perl/CPAN/ |
915 | Belgium ftp://ftp.kulnet.kuleuven.ac.be/pub/mirror/CPAN/ | |
916 | Bulgaria ftp://ftp.ntrl.net/pub/mirrors/CPAN/ | |
917 | Croatia ftp://ftp.linux.hr/pub/CPAN/ | |
918 | Czech Republic ftp://ftp.fi.muni.cz/pub/perl/ | |
be94a901 | 919 | ftp://sunsite.mff.cuni.cz/Languages/Perl/CPAN/ |
0974df93 JH |
920 | Denmark ftp://sunsite.auc.dk/pub/languages/perl/CPAN/ |
921 | Estonia ftp://ftp.ut.ee/pub/languages/perl/CPAN/ | |
922 | Finland ftp://ftp.funet.fi/pub/languages/perl/CPAN/ | |
6cecdcac GS |
923 | France ftp://ftp.grolier.fr/pub/perl/CPAN/ |
924 | ftp://ftp.lip6.fr/pub/perl/CPAN/ | |
be94a901 GS |
925 | ftp://ftp.oleane.net/pub/mirrors/CPAN/ |
926 | ftp://ftp.pasteur.fr/pub/computing/CPAN/ | |
0974df93 | 927 | ftp://ftp.uvsq.fr/pub/perl/CPAN/ |
6cecdcac GS |
928 | German ftp://ftp.gigabell.net/pub/CPAN/ |
929 | Germany ftp://ftp.archive.de.uu.net/pub/CPAN/ | |
930 | ftp://ftp.freenet.de/pub/ftp.cpan.org/pub/ | |
931 | ftp://ftp.gmd.de/packages/CPAN/ | |
932 | ftp://ftp.gwdg.de/pub/languages/perl/CPAN/ | |
2e1d04bc JH |
933 | |
934 | ftp://ftp.leo.org/pub/comp/general/programming/languages/script/perl/CPAN/ | |
6cecdcac GS |
935 | ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/ |
936 | ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/ | |
937 | ftp://ftp.uni-erlangen.de/pub/source/CPAN/ | |
938 | ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/ | |
0974df93 | 939 | Germany ftp://ftp.archive.de.uu.net/pub/CPAN/ |
6cecdcac | 940 | ftp://ftp.freenet.de/pub/ftp.cpan.org/pub/ |
be94a901 GS |
941 | ftp://ftp.gmd.de/packages/CPAN/ |
942 | ftp://ftp.gwdg.de/pub/languages/perl/CPAN/ | |
2e1d04bc JH |
943 | |
944 | ftp://ftp.leo.org/pub/comp/general/programming/languages/script/perl/CPAN/ | |
be94a901 GS |
945 | ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/ |
946 | ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/ | |
947 | ftp://ftp.uni-erlangen.de/pub/source/CPAN/ | |
948 | ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/ | |
0974df93 JH |
949 | Greece ftp://ftp.ntua.gr/pub/lang/perl/ |
950 | Hungary ftp://ftp.kfki.hu/pub/packages/perl/CPAN/ | |
951 | Iceland ftp://ftp.gm.is/pub/CPAN/ | |
952 | Ireland ftp://cpan.indigo.ie/pub/CPAN/ | |
953 | ftp://sunsite.compapp.dcu.ie/pub/perl/ | |
954 | Italy ftp://cis.uniRoma2.it/CPAN/ | |
be94a901 | 955 | ftp://ftp.flashnet.it/pub/CPAN/ |
19799a22 | 956 | ftp://ftp.unina.it/pub/Other/CPAN/ |
be94a901 | 957 | ftp://ftp.unipi.it/pub/mirror/perl/CPAN/ |
0974df93 | 958 | Netherlands ftp://ftp.cs.uu.nl/mirror/CPAN/ |
be94a901 | 959 | ftp://ftp.nluug.nl/pub/languages/perl/CPAN/ |
0974df93 | 960 | Norway ftp://ftp.uit.no/pub/languages/perl/cpan/ |
be94a901 | 961 | ftp://sunsite.uio.no/pub/languages/perl/CPAN/ |
6cecdcac | 962 | Poland ftp://ftp.man.torun.pl/pub/CPAN/ |
be94a901 GS |
963 | ftp://ftp.pk.edu.pl/pub/lang/perl/CPAN/ |
964 | ftp://sunsite.icm.edu.pl/pub/CPAN/ | |
0974df93 | 965 | Portugal ftp://ftp.ci.uminho.pt/pub/mirrors/cpan/ |
19799a22 | 966 | ftp://ftp.ist.utl.pt/pub/CPAN/ |
be94a901 | 967 | ftp://ftp.ua.pt/pub/CPAN/ |
6cecdcac | 968 | Romania ftp://ftp.dnttm.ro/pub/CPAN/ |
19799a22 | 969 | Russia ftp://ftp.chg.ru/pub/lang/perl/CPAN/ |
be94a901 | 970 | ftp://ftp.sai.msu.su/pub/lang/perl/CPAN/ |
0974df93 JH |
971 | Slovakia ftp://ftp.entry.sk/pub/languages/perl/CPAN/ |
972 | Slovenia ftp://ftp.arnes.si/software/perl/CPAN/ | |
973 | Spain ftp://ftp.etse.urv.es/pub/perl/ | |
be94a901 | 974 | ftp://ftp.rediris.es/mirror/CPAN/ |
0974df93 JH |
975 | Sweden ftp://ftp.sunet.se/pub/lang/perl/CPAN/ |
976 | Switzerland ftp://sunsite.cnlab-switch.ch/mirror/CPAN/ | |
977 | Turkey ftp://sunsite.bilkent.edu.tr/pub/languages/CPAN/ | |
978 | United Kingdom ftp://ftp.demon.co.uk/pub/mirrors/perl/CPAN/ | |
be94a901 | 979 | ftp://ftp.flirble.org/pub/languages/perl/CPAN/ |
2e1d04bc JH |
980 | |
981 | ftp://ftp.mirror.ac.uk/sites/ftp.funet.fi/pub/languages/perl/CPAN/ | |
be94a901 GS |
982 | ftp://ftp.plig.org/pub/CPAN/ |
983 | ftp://sunsite.doc.ic.ac.uk/packages/CPAN/ | |
f102b883 | 984 | |
6cecdcac | 985 | |
19799a22 | 986 | =item North America |
f102b883 | 987 | |
0974df93 | 988 | Alberta ftp://sunsite.ualberta.ca/pub/Mirror/CPAN/ |
19799a22 | 989 | California ftp://cpan.nas.nasa.gov/pub/perl/CPAN/ |
0974df93 | 990 | ftp://cpan.valueclick.com/CPAN/ |
19799a22 | 991 | ftp://ftp.cdrom.com/pub/perl/CPAN/ |
6cecdcac | 992 | http://download.sourceforge.net/mirrors/CPAN/ |
0974df93 JH |
993 | Colorado ftp://ftp.cs.colorado.edu/pub/perl/CPAN/ |
994 | Florida ftp://ftp.cise.ufl.edu/pub/perl/CPAN/ | |
6cecdcac | 995 | Georgia ftp://ftp.twoguys.org/CPAN/ |
0974df93 JH |
996 | Illinois ftp://uiarchive.uiuc.edu/pub/lang/perl/CPAN/ |
997 | Indiana ftp://csociety-ftp.ecn.purdue.edu/pub/CPAN/ | |
be94a901 | 998 | ftp://ftp.uwsg.indiana.edu/pub/perl/CPAN/ |
0974df93 JH |
999 | Kentucky ftp://ftp.uky.edu/CPAN/ |
1000 | Manitoba ftp://theoryx5.uwinnipeg.ca/pub/CPAN/ | |
2e1d04bc JH |
1001 | Massachusetts |
1002 | ftp://ftp.ccs.neu.edu/net/mirrors/ftp.funet.fi/pub/languages/perl/CPAN/ | |
be94a901 | 1003 | ftp://ftp.iguide.com/pub/mirrors/packages/perl/CPAN/ |
19799a22 | 1004 | Mexico ftp://ftp.msg.com.mx/pub/CPAN/ |
0974df93 JH |
1005 | New York ftp://ftp.deao.net/pub/CPAN/ |
1006 | ftp://ftp.rge.com/pub/languages/perl/ | |
0974df93 | 1007 | North Carolina ftp://ftp.duke.edu/pub/perl/ |
6cecdcac | 1008 | Nova Scotia ftp://cpan.chebucto.ns.ca/pub/CPAN/ |
0974df93 | 1009 | Oklahoma ftp://ftp.ou.edu/mirrors/CPAN/ |
19799a22 | 1010 | Ontario ftp://ftp.crc.ca/pub/packages/lang/perl/CPAN/ |
0974df93 JH |
1011 | Oregon ftp://ftp.orst.edu/pub/packages/CPAN/ |
1012 | Pennsylvania ftp://ftp.epix.net/pub/languages/perl/ | |
1013 | Tennessee ftp://ftp.sunsite.utk.edu/pub/CPAN/ | |
1014 | Texas ftp://ftp.sedl.org/pub/mirrors/CPAN/ | |
6cecdcac | 1015 | ftp://jhcloos.com/pub/mirror/CPAN/ |
0974df93 JH |
1016 | Utah ftp://mirror.xmission.com/CPAN/ |
1017 | Virginia ftp://ftp.perl.org/pub/perl/CPAN/ | |
be94a901 | 1018 | ftp://ruff.cs.jmu.edu/pub/CPAN/ |
19799a22 | 1019 | Washington ftp://ftp-mirror.internap.com/pub/CPAN/ |
6cecdcac | 1020 | ftp://ftp.llarian.net/pub/CPAN/ |
19799a22 | 1021 | ftp://ftp.spu.edu/pub/CPAN/ |
f102b883 | 1022 | |
6cecdcac | 1023 | |
19799a22 | 1024 | =item South America |
f102b883 | 1025 | |
0974df93 JH |
1026 | Brazil ftp://cpan.if.usp.br/pub/mirror/CPAN/ |
1027 | ftp://ftp.matrix.com.br/pub/perl/ | |
6cecdcac | 1028 | Chile ftp://sunsite.dcc.uchile.cl/pub/Lang/PERL/ |
f102b883 TC |
1029 | |
1030 | =back | |
1031 | ||
1032 | For an up-to-date listing of CPAN sites, | |
6cecdcac | 1033 | see http://www.perl.com/perl/CPAN/SITES or ftp://www.perl.com/CPAN/SITES . |
f102b883 TC |
1034 | |
1035 | =head1 Modules: Creation, Use, and Abuse | |
1036 | ||
1037 | (The following section is borrowed directly from Tim Bunce's modules | |
1038 | file, available at your nearest CPAN site.) | |
1039 | ||
1040 | Perl implements a class using a package, but the presence of a | |
1041 | package doesn't imply the presence of a class. A package is just a | |
1042 | namespace. A class is a package that provides subroutines that can be | |
1043 | used as methods. A method is just a subroutine that expects, as its | |
1044 | first argument, either the name of a package (for "static" methods), | |
1045 | or a reference to something (for "virtual" methods). | |
1046 | ||
1047 | A module is a file that (by convention) provides a class of the same | |
1048 | name (sans the .pm), plus an import method in that class that can be | |
1049 | called to fetch exported symbols. This module may implement some of | |
1050 | its methods by loading dynamic C or C++ objects, but that should be | |
1051 | totally transparent to the user of the module. Likewise, the module | |
1052 | might set up an AUTOLOAD function to slurp in subroutine definitions on | |
1053 | demand, but this is also transparent. Only the F<.pm> file is required to | |
2e1d04bc | 1054 | exist. See L<perlsub>, L<perltoot>, and L<AutoLoader> for details about |
f102b883 TC |
1055 | the AUTOLOAD mechanism. |
1056 | ||
1057 | =head2 Guidelines for Module Creation | |
1058 | ||
1059 | =over 4 | |
1060 | ||
1061 | =item Do similar modules already exist in some form? | |
1062 | ||
1063 | If so, please try to reuse the existing modules either in whole or | |
1064 | by inheriting useful features into a new class. If this is not | |
1065 | practical try to get together with the module authors to work on | |
1066 | extending or enhancing the functionality of the existing modules. | |
1067 | A perfect example is the plethora of packages in perl4 for dealing | |
1068 | with command line options. | |
1069 | ||
1070 | If you are writing a module to expand an already existing set of | |
1071 | modules, please coordinate with the author of the package. It | |
1072 | helps if you follow the same naming scheme and module interaction | |
1073 | scheme as the original author. | |
1074 | ||
1075 | =item Try to design the new module to be easy to extend and reuse. | |
1076 | ||
9f1b1f2d GS |
1077 | Try to C<use warnings;> (or C<use warnings qw(...);>). |
1078 | Remember that you can add C<no warnings qw(...);> to individual blocks | |
2e1d04bc | 1079 | of code that need less warnings. |
19799a22 | 1080 | |
f102b883 TC |
1081 | Use blessed references. Use the two argument form of bless to bless |
1082 | into the class name given as the first parameter of the constructor, | |
1083 | e.g.,: | |
1084 | ||
1085 | sub new { | |
2e1d04bc JH |
1086 | my $class = shift; |
1087 | return bless {}, $class; | |
f102b883 TC |
1088 | } |
1089 | ||
1090 | or even this if you'd like it to be used as either a static | |
1091 | or a virtual method. | |
1092 | ||
1093 | sub new { | |
2e1d04bc JH |
1094 | my $self = shift; |
1095 | my $class = ref($self) || $self; | |
1096 | return bless {}, $class; | |
f102b883 TC |
1097 | } |
1098 | ||
1099 | Pass arrays as references so more parameters can be added later | |
1100 | (it's also faster). Convert functions into methods where | |
1101 | appropriate. Split large methods into smaller more flexible ones. | |
1102 | Inherit methods from other modules if appropriate. | |
1103 | ||
1104 | Avoid class name tests like: C<die "Invalid" unless ref $ref eq 'FOO'>. | |
19799a22 | 1105 | Generally you can delete the C<eq 'FOO'> part with no harm at all. |
f102b883 TC |
1106 | Let the objects look after themselves! Generally, avoid hard-wired |
1107 | class names as far as possible. | |
1108 | ||
c47ff5f1 GS |
1109 | Avoid C<< $r->Class::func() >> where using C<@ISA=qw(... Class ...)> and |
1110 | C<< $r->func() >> would work (see L<perlbot> for more details). | |
f102b883 TC |
1111 | |
1112 | Use autosplit so little used or newly added functions won't be a | |
5a964f20 | 1113 | burden to programs that don't use them. Add test functions to |
f102b883 TC |
1114 | the module after __END__ either using AutoSplit or by saying: |
1115 | ||
1116 | eval join('',<main::DATA>) || die $@ unless caller(); | |
1117 | ||
1118 | Does your module pass the 'empty subclass' test? If you say | |
19799a22 | 1119 | C<@SUBCLASS::ISA = qw(YOURCLASS);> your applications should be able |
f102b883 TC |
1120 | to use SUBCLASS in exactly the same way as YOURCLASS. For example, |
1121 | does your application still work if you change: C<$obj = new YOURCLASS;> | |
1122 | into: C<$obj = new SUBCLASS;> ? | |
1123 | ||
1124 | Avoid keeping any state information in your packages. It makes it | |
1125 | difficult for multiple other packages to use yours. Keep state | |
1126 | information in objects. | |
1127 | ||
2e1d04bc | 1128 | Always use B<-w>. |
19799a22 GS |
1129 | |
1130 | Try to C<use strict;> (or C<use strict qw(...);>). | |
f102b883 | 1131 | Remember that you can add C<no strict qw(...);> to individual blocks |
2e1d04bc | 1132 | of code that need less strictness. |
19799a22 | 1133 | |
2e1d04bc | 1134 | Always use B<-w>. |
19799a22 | 1135 | |
f102b883 TC |
1136 | Follow the guidelines in the perlstyle(1) manual. |
1137 | ||
19799a22 GS |
1138 | Always use B<-w>. |
1139 | ||
f102b883 TC |
1140 | =item Some simple style guidelines |
1141 | ||
5a964f20 | 1142 | The perlstyle manual supplied with Perl has many helpful points. |
f102b883 TC |
1143 | |
1144 | Coding style is a matter of personal taste. Many people evolve their | |
1145 | style over several years as they learn what helps them write and | |
1146 | maintain good code. Here's one set of assorted suggestions that | |
1147 | seem to be widely used by experienced developers: | |
1148 | ||
1149 | Use underscores to separate words. It is generally easier to read | |
1150 | $var_names_like_this than $VarNamesLikeThis, especially for | |
1151 | non-native speakers of English. It's also a simple rule that works | |
1152 | consistently with VAR_NAMES_LIKE_THIS. | |
1153 | ||
1154 | Package/Module names are an exception to this rule. Perl informally | |
1155 | reserves lowercase module names for 'pragma' modules like integer | |
1156 | and strict. Other modules normally begin with a capital letter and | |
1157 | use mixed case with no underscores (need to be short and portable). | |
1158 | ||
1159 | You may find it helpful to use letter case to indicate the scope | |
1160 | or nature of a variable. For example: | |
1161 | ||
5a964f20 | 1162 | $ALL_CAPS_HERE constants only (beware clashes with Perl vars) |
f102b883 TC |
1163 | $Some_Caps_Here package-wide global/static |
1164 | $no_caps_here function scope my() or local() variables | |
1165 | ||
1166 | Function and method names seem to work best as all lowercase. | |
c47ff5f1 | 1167 | e.g., C<< $obj->as_string() >>. |
f102b883 TC |
1168 | |
1169 | You can use a leading underscore to indicate that a variable or | |
1170 | function should not be used outside the package that defined it. | |
1171 | ||
1172 | =item Select what to export. | |
1173 | ||
1174 | Do NOT export method names! | |
1175 | ||
1176 | Do NOT export anything else by default without a good reason! | |
1177 | ||
1178 | Exports pollute the namespace of the module user. If you must | |
1179 | export try to use @EXPORT_OK in preference to @EXPORT and avoid | |
1180 | short or common names to reduce the risk of name clashes. | |
1181 | ||
1182 | Generally anything not exported is still accessible from outside the | |
c47ff5f1 | 1183 | module using the ModuleName::item_name (or C<< $blessed_ref->method >>) |
f102b883 TC |
1184 | syntax. By convention you can use a leading underscore on names to |
1185 | indicate informally that they are 'internal' and not for public use. | |
1186 | ||
1187 | (It is actually possible to get private functions by saying: | |
1188 | C<my $subref = sub { ... }; &$subref;>. But there's no way to call that | |
1189 | directly as a method, because a method must have a name in the symbol | |
1190 | table.) | |
1191 | ||
1192 | As a general rule, if the module is trying to be object oriented | |
1193 | then export nothing. If it's just a collection of functions then | |
1194 | @EXPORT_OK anything but use @EXPORT with caution. | |
1195 | ||
1196 | =item Select a name for the module. | |
1197 | ||
1198 | This name should be as descriptive, accurate, and complete as | |
1199 | possible. Avoid any risk of ambiguity. Always try to use two or | |
1200 | more whole words. Generally the name should reflect what is special | |
1201 | about what the module does rather than how it does it. Please use | |
1202 | nested module names to group informally or categorize a module. | |
1203 | There should be a very good reason for a module not to have a nested name. | |
1204 | Module names should begin with a capital letter. | |
1205 | ||
1206 | Having 57 modules all called Sort will not make life easy for anyone | |
1207 | (though having 23 called Sort::Quick is only marginally better :-). | |
1208 | Imagine someone trying to install your module alongside many others. | |
1209 | If in any doubt ask for suggestions in comp.lang.perl.misc. | |
1210 | ||
1211 | If you are developing a suite of related modules/classes it's good | |
1212 | practice to use nested classes with a common prefix as this will | |
1213 | avoid namespace clashes. For example: Xyz::Control, Xyz::View, | |
1214 | Xyz::Model etc. Use the modules in this list as a naming guide. | |
1215 | ||
1216 | If adding a new module to a set, follow the original author's | |
1217 | standards for naming modules and the interface to methods in | |
1218 | those modules. | |
1219 | ||
1220 | To be portable each component of a module name should be limited to | |
1221 | 11 characters. If it might be used on MS-DOS then try to ensure each is | |
1222 | unique in the first 8 characters. Nested modules make this easier. | |
1223 | ||
1224 | =item Have you got it right? | |
1225 | ||
1226 | How do you know that you've made the right decisions? Have you | |
1227 | picked an interface design that will cause problems later? Have | |
1228 | you picked the most appropriate name? Do you have any questions? | |
1229 | ||
1230 | The best way to know for sure, and pick up many helpful suggestions, | |
1231 | is to ask someone who knows. Comp.lang.perl.misc is read by just about | |
1232 | all the people who develop modules and it's the best place to ask. | |
1233 | ||
1234 | All you need to do is post a short summary of the module, its | |
1235 | purpose and interfaces. A few lines on each of the main methods is | |
1236 | probably enough. (If you post the whole module it might be ignored | |
1237 | by busy people - generally the very people you want to read it!) | |
1238 | ||
1239 | Don't worry about posting if you can't say when the module will be | |
1240 | ready - just say so in the message. It might be worth inviting | |
1241 | others to help you, they may be able to complete it for you! | |
1242 | ||
1243 | =item README and other Additional Files. | |
1244 | ||
1245 | It's well known that software developers usually fully document the | |
1246 | software they write. If, however, the world is in urgent need of | |
1247 | your software and there is not enough time to write the full | |
1248 | documentation please at least provide a README file containing: | |
1249 | ||
1250 | =over 10 | |
1251 | ||
1252 | =item * | |
1253 | A description of the module/package/extension etc. | |
1254 | ||
1255 | =item * | |
1256 | A copyright notice - see below. | |
1257 | ||
1258 | =item * | |
1259 | Prerequisites - what else you may need to have. | |
1260 | ||
1261 | =item * | |
1262 | How to build it - possible changes to Makefile.PL etc. | |
1263 | ||
1264 | =item * | |
1265 | How to install it. | |
1266 | ||
1267 | =item * | |
1268 | Recent changes in this release, especially incompatibilities | |
1269 | ||
1270 | =item * | |
1271 | Changes / enhancements you plan to make in the future. | |
1272 | ||
1273 | =back | |
1274 | ||
1275 | If the README file seems to be getting too large you may wish to | |
1276 | split out some of the sections into separate files: INSTALL, | |
1277 | Copying, ToDo etc. | |
1278 | ||
1279 | =over 4 | |
1280 | ||
1281 | =item Adding a Copyright Notice. | |
1282 | ||
1283 | How you choose to license your work is a personal decision. | |
1284 | The general mechanism is to assert your Copyright and then make | |
1285 | a declaration of how others may copy/use/modify your work. | |
1286 | ||
1287 | Perl, for example, is supplied with two types of licence: The GNU | |
1288 | GPL and The Artistic Licence (see the files README, Copying, and | |
1289 | Artistic). Larry has good reasons for NOT just using the GNU GPL. | |
1290 | ||
1291 | My personal recommendation, out of respect for Larry, Perl, and the | |
5a964f20 | 1292 | Perl community at large is to state something simply like: |
f102b883 TC |
1293 | |
1294 | Copyright (c) 1995 Your Name. All rights reserved. | |
1295 | This program is free software; you can redistribute it and/or | |
1296 | modify it under the same terms as Perl itself. | |
1297 | ||
1298 | This statement should at least appear in the README file. You may | |
1299 | also wish to include it in a Copying file and your source files. | |
1300 | Remember to include the other words in addition to the Copyright. | |
1301 | ||
1302 | =item Give the module a version/issue/release number. | |
1303 | ||
1304 | To be fully compatible with the Exporter and MakeMaker modules you | |
1305 | should store your module's version number in a non-my package | |
1306 | variable called $VERSION. This should be a floating point | |
1307 | number with at least two digits after the decimal (i.e., hundredths, | |
1308 | e.g, C<$VERSION = "0.01">). Don't use a "1.3.2" style version. | |
19799a22 | 1309 | See L<Exporter> for details. |
f102b883 TC |
1310 | |
1311 | It may be handy to add a function or method to retrieve the number. | |
1312 | Use the number in announcements and archive file names when | |
1313 | releasing the module (ModuleName-1.02.tar.Z). | |
1314 | See perldoc ExtUtils::MakeMaker.pm for details. | |
1315 | ||
1316 | =item How to release and distribute a module. | |
1317 | ||
1318 | It's good idea to post an announcement of the availability of your | |
1319 | module (or the module itself if small) to the comp.lang.perl.announce | |
1320 | Usenet newsgroup. This will at least ensure very wide once-off | |
1321 | distribution. | |
1322 | ||
2e1d04bc | 1323 | If possible, register the module with CPAN. You should |
f102b883 TC |
1324 | include details of its location in your announcement. |
1325 | ||
1326 | Some notes about ftp archives: Please use a long descriptive file | |
5a964f20 | 1327 | name that includes the version number. Most incoming directories |
f102b883 TC |
1328 | will not be readable/listable, i.e., you won't be able to see your |
1329 | file after uploading it. Remember to send your email notification | |
1330 | message as soon as possible after uploading else your file may get | |
1331 | deleted automatically. Allow time for the file to be processed | |
1332 | and/or check the file has been processed before announcing its | |
1333 | location. | |
1334 | ||
1335 | FTP Archives for Perl Modules: | |
1336 | ||
6cecdcac | 1337 | Follow the instructions and links on: |
f102b883 | 1338 | |
6cecdcac GS |
1339 | http://www.perl.com/CPAN/modules/00modlist.long.html |
1340 | http://www.perl.com/CPAN/modules/04pause.html | |
f102b883 TC |
1341 | |
1342 | or upload to one of these sites: | |
1343 | ||
6cecdcac GS |
1344 | https://pause.kbx.de/pause/ |
1345 | http://pause.perl.org/pause/ | |
f102b883 | 1346 | |
6cecdcac | 1347 | and notify <modules@perl.org>. |
f102b883 TC |
1348 | |
1349 | By using the WWW interface you can ask the Upload Server to mirror | |
1350 | your modules from your ftp or WWW site into your own directory on | |
1351 | CPAN! | |
1352 | ||
1353 | Please remember to send me an updated entry for the Module list! | |
1354 | ||
1355 | =item Take care when changing a released module. | |
1356 | ||
7b8d334a GS |
1357 | Always strive to remain compatible with previous released versions. |
1358 | Otherwise try to add a mechanism to revert to the | |
19799a22 | 1359 | old behavior if people rely on it. Document incompatible changes. |
f102b883 TC |
1360 | |
1361 | =back | |
1362 | ||
1363 | =back | |
1364 | ||
1365 | =head2 Guidelines for Converting Perl 4 Library Scripts into Modules | |
1366 | ||
1367 | =over 4 | |
1368 | ||
1369 | =item There is no requirement to convert anything. | |
1370 | ||
1371 | If it ain't broke, don't fix it! Perl 4 library scripts should | |
1372 | continue to work with no problems. You may need to make some minor | |
1373 | changes (like escaping non-array @'s in double quoted strings) but | |
1374 | there is no need to convert a .pl file into a Module for just that. | |
1375 | ||
1376 | =item Consider the implications. | |
1377 | ||
5a964f20 | 1378 | All Perl applications that make use of the script will need to |
f102b883 TC |
1379 | be changed (slightly) if the script is converted into a module. Is |
1380 | it worth it unless you plan to make other changes at the same time? | |
1381 | ||
1382 | =item Make the most of the opportunity. | |
1383 | ||
1384 | If you are going to convert the script to a module you can use the | |
19799a22 GS |
1385 | opportunity to redesign the interface. The guidelines for module |
1386 | creation above include many of the issues you should consider. | |
f102b883 TC |
1387 | |
1388 | =item The pl2pm utility will get you started. | |
1389 | ||
1390 | This utility will read *.pl files (given as parameters) and write | |
1391 | corresponding *.pm files. The pl2pm utilities does the following: | |
1392 | ||
1393 | =over 10 | |
1394 | ||
1395 | =item * | |
1396 | Adds the standard Module prologue lines | |
1397 | ||
1398 | =item * | |
1399 | Converts package specifiers from ' to :: | |
1400 | ||
1401 | =item * | |
1402 | Converts die(...) to croak(...) | |
1403 | ||
1404 | =item * | |
1405 | Several other minor changes | |
1406 | ||
1407 | =back | |
1408 | ||
1409 | Being a mechanical process pl2pm is not bullet proof. The converted | |
1410 | code will need careful checking, especially any package statements. | |
1411 | Don't delete the original .pl file till the new .pm one works! | |
1412 | ||
1413 | =back | |
1414 | ||
1415 | =head2 Guidelines for Reusing Application Code | |
1416 | ||
1417 | =over 4 | |
1418 | ||
1419 | =item Complete applications rarely belong in the Perl Module Library. | |
1420 | ||
5a964f20 | 1421 | =item Many applications contain some Perl code that could be reused. |
f102b883 TC |
1422 | |
1423 | Help save the world! Share your code in a form that makes it easy | |
1424 | to reuse. | |
1425 | ||
1426 | =item Break-out the reusable code into one or more separate module files. | |
1427 | ||
1428 | =item Take the opportunity to reconsider and redesign the interfaces. | |
1429 | ||
1430 | =item In some cases the 'application' can then be reduced to a small | |
1431 | ||
1432 | fragment of code built on top of the reusable modules. In these cases | |
1433 | the application could invoked as: | |
1434 | ||
5a964f20 | 1435 | % perl -e 'use Module::Name; method(@ARGV)' ... |
f102b883 | 1436 | or |
5a964f20 | 1437 | % perl -mModule::Name ... (in perl5.002 or higher) |
f102b883 TC |
1438 | |
1439 | =back | |
1440 | ||
1441 | =head1 NOTE | |
1442 | ||
1443 | Perl does not enforce private and public parts of its modules as you may | |
1444 | have been used to in other languages like C++, Ada, or Modula-17. Perl | |
1445 | doesn't have an infatuation with enforced privacy. It would prefer | |
1446 | that you stayed out of its living room because you weren't invited, not | |
1447 | because it has a shotgun. | |
1448 | ||
1449 | The module and its user have a contract, part of which is common law, | |
1450 | and part of which is "written". Part of the common law contract is | |
1451 | that a module doesn't pollute any namespace it wasn't asked to. The | |
1452 | written contract for the module (A.K.A. documentation) may make other | |
1453 | provisions. But then you know when you C<use RedefineTheWorld> that | |
1454 | you're redefining the world and willing to take the consequences. |