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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 | |
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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. |
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22 | |
23 | =head2 Pragmatic Modules |
24 | |
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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: |
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30 | |
31 | no integer; |
32 | no strict 'refs'; |
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33 | no warnings; |
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34 | |
35 | which lasts until the end of that BLOCK. |
36 | |
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37 | Some pragmas are lexically scoped--typically those that affect the |
38 | C<$^H> hints variable. Others affect the current package instead, |
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39 | like C<use vars> and C<use subs>, which allow you to predeclare a |
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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>. |
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44 | |
45 | The following pragmas are defined (and have their own documentation). |
46 | |
47 | =over 12 |
48 | |
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49 | =item attributes |
50 | |
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51 | Get/set subroutine or variable attributes |
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52 | |
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53 | =item attrs |
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54 | |
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55 | Set/get attributes of a subroutine (deprecated) |
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56 | |
57 | =item autouse |
58 | |
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59 | Postpone load of modules until a function is used |
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60 | |
61 | =item base |
62 | |
63 | Establish IS-A relationship with base class at compile time |
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64 | |
65 | =item blib |
66 | |
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67 | Use MakeMaker's uninstalled version of a package |
68 | |
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69 | =item bytes |
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70 | |
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71 | Force byte semantics rather than character semantics |
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72 | |
73 | =item charnames |
74 | |
75 | Define character names for C<\N{named}> string literal escape. |
76 | |
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77 | =item constant |
78 | |
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79 | Declare constants |
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80 | |
81 | =item diagnostics |
82 | |
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83 | Perl compiler pragma to force verbose warning diagnostics |
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84 | |
85 | =item fields |
86 | |
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87 | Compile-time class fields |
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88 | |
89 | =item filetest |
90 | |
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91 | Control the filetest permission operators |
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92 | |
93 | =item integer |
94 | |
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95 | Compute arithmetic in integer instead of double |
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96 | |
97 | =item less |
98 | |
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99 | Request less of something from the compiler |
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100 | |
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101 | =item locale |
102 | |
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103 | Use and avoid POSIX locales for built-in operations |
104 | |
105 | =item open |
106 | |
107 | Set default disciplines for input and output |
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108 | |
109 | =item ops |
110 | |
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111 | Restrict unsafe operations when compiling |
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112 | |
113 | =item overload |
114 | |
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115 | Package for overloading perl operations |
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116 | |
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117 | =item perlio |
118 | |
119 | Configure C level IO |
120 | |
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121 | =item re |
122 | |
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123 | Alter regular expression behaviour |
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124 | |
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125 | =item sigtrap |
126 | |
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127 | Enable simple signal handling |
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128 | |
129 | =item strict |
130 | |
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131 | Restrict unsafe constructs |
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132 | |
133 | =item subs |
134 | |
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135 | Predeclare sub names |
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136 | |
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137 | =item utf8 |
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138 | |
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139 | Enable/disable UTF-8 in source code |
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140 | |
141 | =item vars |
142 | |
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143 | Predeclare global variable names (obsolete) |
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144 | |
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145 | =item warnings |
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146 | |
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147 | Control optional warnings |
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148 | |
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149 | =item warnings::register |
150 | |
151 | Warnings import function |
152 | |
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153 | =back |
154 | |
155 | =head2 Standard Modules |
156 | |
157 | Standard, bundled modules are all expected to behave in a well-defined |
158 | manner with respect to namespace pollution because they use the |
159 | Exporter module. See their own documentation for details. |
160 | |
161 | =over 12 |
162 | |
163 | =item AnyDBM_File |
164 | |
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165 | Provide framework for multiple DBMs |
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166 | |
167 | =item AutoLoader |
168 | |
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169 | Load subroutines only on demand |
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170 | |
171 | =item AutoSplit |
172 | |
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173 | Split a package for autoloading |
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174 | |
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175 | =item B |
176 | |
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177 | The Perl Compiler |
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178 | |
179 | =item B::Asmdata |
180 | |
181 | Autogenerated data about Perl ops, used to generate bytecode |
182 | |
183 | =item B::Assembler |
184 | |
185 | Assemble Perl bytecode |
186 | |
187 | =item B::Bblock |
188 | |
189 | Walk basic blocks |
190 | |
191 | =item B::Bytecode |
192 | |
193 | Perl compiler's bytecode backend |
194 | |
195 | =item B::C |
196 | |
197 | Perl compiler's C backend |
198 | |
199 | =item B::CC |
200 | |
201 | Perl compiler's optimized C translation backend |
202 | |
203 | =item B::Debug |
204 | |
205 | Walk Perl syntax tree, printing debug info about ops |
206 | |
207 | =item B::Deparse |
208 | |
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209 | Perl compiler backend to produce perl code |
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210 | |
211 | =item B::Disassembler |
212 | |
213 | Disassemble Perl bytecode |
214 | |
215 | =item B::Lint |
216 | |
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217 | Perl lint |
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218 | |
219 | =item B::Showlex |
220 | |
221 | Show lexical variables used in functions or files |
222 | |
223 | =item B::Stackobj |
224 | |
225 | Helper module for CC backend |
226 | |
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227 | =item B::Stash |
228 | |
229 | Show what stashes are loaded |
230 | |
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231 | =item B::Terse |
232 | |
233 | Walk Perl syntax tree, printing terse info about ops |
234 | |
235 | =item B::Xref |
236 | |
237 | Generates cross reference reports for Perl programs |
238 | |
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239 | =item Benchmark |
240 | |
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241 | Benchmark running times of Perl code |
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242 | |
243 | =item ByteLoader |
244 | |
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245 | Load byte compiled perl code |
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246 | |
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247 | =item CGI |
248 | |
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249 | Simple Common Gateway Interface Class |
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250 | |
251 | =item CGI::Apache |
252 | |
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253 | Backward compatibility module for CGI.pm |
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254 | |
255 | =item CGI::Carp |
256 | |
257 | CGI routines for writing to the HTTPD (or other) error log |
258 | |
259 | =item CGI::Cookie |
260 | |
261 | Interface to Netscape Cookies |
262 | |
263 | =item CGI::Fast |
264 | |
265 | CGI Interface for Fast CGI |
266 | |
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267 | =item CGI::Pretty |
268 | |
269 | Module to produce nicely formatted HTML code |
270 | |
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271 | =item CGI::Push |
272 | |
273 | Simple Interface to Server Push |
274 | |
275 | =item CGI::Switch |
276 | |
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277 | Backward compatibility module for defunct CGI::Switch |
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278 | |
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279 | =item CPAN |
280 | |
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281 | Query, download and build perl modules from CPAN sites |
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282 | |
283 | =item CPAN::FirstTime |
284 | |
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285 | Utility for CPAN::Config file Initialization |
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286 | |
287 | =item CPAN::Nox |
288 | |
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289 | Wrapper around CPAN.pm without using any XS module |
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290 | |
291 | =item Carp |
292 | |
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293 | Warn of errors (from perspective of caller) |
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294 | |
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295 | =item Class::Struct |
296 | |
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297 | Declare struct-like datatypes as Perl classes |
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298 | |
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299 | =item Cwd |
300 | |
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301 | Get pathname of current working directory |
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302 | |
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303 | =item DB |
304 | |
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305 | Programmatic interface to the Perl debugging API (draft, subject to |
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306 | |
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307 | =item DB_File |
308 | |
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309 | Perl5 access to Berkeley DB version 1.x |
310 | |
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311 | =item Devel::SelfStubber |
312 | |
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313 | Generate stubs for a SelfLoading module |
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314 | |
315 | =item DirHandle |
316 | |
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317 | Supply object methods for directory handles |
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318 | |
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319 | =item Dumpvalue |
320 | |
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321 | Provides screen dump of Perl data. |
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322 | |
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323 | =item Encode |
324 | |
325 | Character encodings |
326 | |
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327 | =item English |
328 | |
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329 | Use nice English (or awk) names for ugly punctuation variables |
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330 | |
331 | =item Env |
332 | |
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333 | Perl module that imports environment variables as scalars or arrays |
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334 | |
335 | =item Exporter |
336 | |
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337 | Implements default import method for modules |
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338 | |
339 | =item Exporter::Heavy |
340 | |
341 | Exporter guts |
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342 | |
343 | =item ExtUtils::Command |
344 | |
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345 | Utilities to replace common UNIX commands in Makefiles etc. |
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346 | |
347 | =item ExtUtils::Embed |
348 | |
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349 | Utilities for embedding Perl in C/C++ applications |
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350 | |
351 | =item ExtUtils::Install |
352 | |
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353 | Install files from here to there |
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354 | |
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355 | =item ExtUtils::Installed |
356 | |
357 | Inventory management of installed modules |
358 | |
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359 | =item ExtUtils::Liblist |
360 | |
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361 | Determine libraries to use and how to use them |
362 | |
363 | =item ExtUtils::MM_Cygwin |
364 | |
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365 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
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366 | |
367 | =item ExtUtils::MM_OS2 |
368 | |
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369 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
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370 | |
371 | =item ExtUtils::MM_Unix |
372 | |
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373 | Methods used by ExtUtils::MakeMaker |
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374 | |
375 | =item ExtUtils::MM_VMS |
376 | |
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377 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
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378 | |
379 | =item ExtUtils::MM_Win32 |
380 | |
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381 | Methods to override UN*X behaviour in ExtUtils::MakeMaker |
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382 | |
383 | =item ExtUtils::MakeMaker |
384 | |
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385 | Create an extension Makefile |
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386 | |
387 | =item ExtUtils::Manifest |
388 | |
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389 | Utilities to write and check a MANIFEST file |
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390 | |
391 | =item ExtUtils::Mkbootstrap |
392 | |
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393 | Make a bootstrap file for use by DynaLoader |
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394 | |
395 | =item ExtUtils::Mksymlists |
396 | |
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397 | Write linker options files for dynamic extension |
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398 | |
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399 | =item ExtUtils::Packlist |
400 | |
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401 | Manage .packlist files |
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402 | |
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403 | =item ExtUtils::testlib |
404 | |
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405 | Add blib/* directories to @INC |
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406 | |
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407 | =item Fatal |
408 | |
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409 | Replace functions with equivalents which succeed or die |
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410 | |
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411 | =item Fcntl |
412 | |
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413 | Load the C Fcntl.h defines |
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414 | |
415 | =item File::Basename |
416 | |
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417 | Split a pathname into pieces |
418 | |
419 | =item File::CheckTree |
420 | |
421 | Run many filetest checks on a tree |
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422 | |
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423 | =item File::Compare |
424 | |
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425 | Compare files or filehandles |
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426 | |
427 | =item File::Copy |
428 | |
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429 | Copy files or filehandles |
430 | |
431 | =item File::DosGlob |
432 | |
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433 | DOS like globbing and then some |
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434 | |
435 | =item File::Find |
436 | |
2e1d04bc |
437 | Traverse a file tree |
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438 | |
439 | =item File::Path |
440 | |
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441 | Create or remove directory trees |
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442 | |
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443 | =item File::Spec |
444 | |
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445 | Portably perform operations on file names |
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446 | |
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447 | =item File::Spec::Epoc |
448 | |
449 | Methods for Epoc file specs |
450 | |
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451 | =item File::Spec::Functions |
452 | |
9e107c59 |
453 | Portably perform operations on file names |
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454 | |
455 | =item File::Spec::Mac |
456 | |
457 | File::Spec for MacOS |
458 | |
459 | =item File::Spec::OS2 |
460 | |
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461 | Methods for OS/2 file specs |
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462 | |
463 | =item File::Spec::Unix |
464 | |
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465 | Methods used by File::Spec |
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466 | |
467 | =item File::Spec::VMS |
468 | |
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469 | Methods for VMS file specs |
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470 | |
471 | =item File::Spec::Win32 |
472 | |
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473 | Methods for Win32 file specs |
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474 | |
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475 | =item File::Temp |
476 | |
477 | Return name and handle of a temporary file safely |
478 | |
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479 | =item File::stat |
480 | |
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481 | By-name interface to Perl's built-in stat() functions |
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482 | |
483 | =item FileCache |
484 | |
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485 | Keep more files open than the system permits |
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486 | |
487 | =item FileHandle |
488 | |
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489 | Supply object methods for filehandles |
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490 | |
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491 | =item Filter::Simple |
492 | |
493 | Simplified source filtering |
494 | |
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495 | =item FindBin |
496 | |
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497 | Locate directory of original perl script |
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498 | |
499 | =item Getopt::Long |
500 | |
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501 | Extended processing of command line options |
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502 | |
503 | =item Getopt::Std |
504 | |
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505 | Process single-character switches with switch clustering |
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506 | |
507 | =item I18N::Collate |
508 | |
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509 | Compare 8-bit scalar data according to the current locale |
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510 | |
511 | =item IO |
512 | |
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513 | Load various IO modules |
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514 | |
515 | =item IPC::Open2 |
516 | |
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517 | Open a process for both reading and writing |
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518 | |
519 | =item IPC::Open3 |
520 | |
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521 | Open a process for reading, writing, and error handling |
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522 | |
523 | =item Math::BigFloat |
524 | |
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525 | Arbitrary length float math package |
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526 | |
527 | =item Math::BigInt |
528 | |
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529 | Arbitrary size integer math package |
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530 | |
531 | =item Math::Complex |
532 | |
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533 | Complex numbers and associated mathematical functions |
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534 | |
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535 | =item Math::Trig |
536 | |
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537 | Trigonometric functions |
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538 | |
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539 | =item NDBM_File |
540 | |
541 | Tied access to ndbm files |
542 | |
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543 | =item Net::Ping |
544 | |
9e107c59 |
545 | Check a remote host for reachability |
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546 | |
547 | =item Net::hostent |
548 | |
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549 | By-name interface to Perl's built-in gethost*() functions |
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550 | |
551 | =item Net::netent |
552 | |
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553 | By-name interface to Perl's built-in getnet*() functions |
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554 | |
555 | =item Net::protoent |
556 | |
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557 | By-name interface to Perl's built-in getproto*() functions |
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558 | |
559 | =item Net::servent |
560 | |
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561 | By-name interface to Perl's built-in getserv*() functions |
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562 | |
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563 | =item O |
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564 | |
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565 | Generic interface to Perl Compiler backends |
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566 | |
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567 | =item ODBM_File |
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568 | |
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569 | Tied access to odbm files |
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570 | |
2e1d04bc |
571 | =item Opcode |
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572 | |
2e1d04bc |
573 | Disable named opcodes when compiling perl code |
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574 | |
9e107c59 |
575 | =item Pod::Checker |
576 | |
577 | Check pod documents for syntax errors |
578 | |
2e1d04bc |
579 | =item Pod::Find |
580 | |
581 | Find POD documents in directory trees |
582 | |
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583 | =item Pod::Html |
584 | |
9e107c59 |
585 | Module to convert pod files to HTML |
586 | |
587 | =item Pod::InputObjects |
588 | |
2e1d04bc |
589 | Objects representing POD input paragraphs, commands, etc. |
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590 | |
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591 | =item Pod::LaTeX |
592 | |
593 | Convert Pod data to formatted Latex |
594 | |
9e107c59 |
595 | =item Pod::Man |
596 | |
597 | Convert POD data to formatted *roff input |
598 | |
2e1d04bc |
599 | =item Pod::ParseUtils |
600 | |
601 | Helpers for POD parsing and conversion |
602 | |
9e107c59 |
603 | =item Pod::Parser |
604 | |
605 | Base class for creating POD filters and translators |
606 | |
2e1d04bc |
607 | =item Pod::Plainer |
608 | |
609 | Perl extension for converting Pod to old style Pod. |
610 | |
9e107c59 |
611 | =item Pod::Select |
612 | |
613 | Extract selected sections of POD from input |
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614 | |
615 | =item Pod::Text |
616 | |
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617 | Convert POD data to formatted ASCII text |
618 | |
619 | =item Pod::Text::Color |
620 | |
621 | Convert POD data to formatted color ASCII text |
622 | |
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623 | =item Pod::Text::Termcap |
624 | |
625 | Convert POD data to ASCII text with format escapes |
626 | |
9e107c59 |
627 | =item Pod::Usage |
628 | |
629 | Print a usage message from embedded pod documentation |
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630 | |
631 | =item SDBM_File |
632 | |
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633 | Tied access to sdbm files |
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634 | |
635 | =item Safe |
636 | |
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637 | Compile and execute code in restricted compartments |
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638 | |
639 | =item Search::Dict |
640 | |
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641 | Search for key in dictionary file |
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642 | |
643 | =item SelectSaver |
644 | |
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645 | Save and restore selected file handle |
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646 | |
647 | =item SelfLoader |
648 | |
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649 | Load functions only on demand |
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650 | |
651 | =item Shell |
652 | |
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653 | Run shell commands transparently within perl |
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654 | |
655 | =item Socket |
656 | |
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657 | Load the C socket.h defines and structure manipulators |
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658 | |
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659 | =item Storable |
660 | |
661 | Persistency for perl data structures |
662 | |
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663 | =item Symbol |
664 | |
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665 | Manipulate Perl symbols and their names |
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666 | |
2e1d04bc |
667 | =item Term::ANSIColor |
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668 | |
2e1d04bc |
669 | Color screen output using ANSI escape sequences |
f102b883 |
670 | |
671 | =item Term::Cap |
672 | |
2e1d04bc |
673 | Perl termcap interface |
f102b883 |
674 | |
675 | =item Term::Complete |
676 | |
2e1d04bc |
677 | Perl word completion module |
f102b883 |
678 | |
679 | =item Term::ReadLine |
680 | |
2e1d04bc |
681 | Perl interface to various C<readline> packages. If |
19799a22 |
682 | |
683 | =item Test |
684 | |
9e107c59 |
685 | Provides a simple framework for writing test scripts |
f102b883 |
686 | |
687 | =item Test::Harness |
688 | |
2e1d04bc |
689 | Run perl standard test scripts with statistics |
f102b883 |
690 | |
691 | =item Text::Abbrev |
692 | |
9e107c59 |
693 | Create an abbreviation table from a list |
f102b883 |
694 | |
695 | =item Text::ParseWords |
696 | |
2e1d04bc |
697 | Parse text into an array of tokens or array of arrays |
f102b883 |
698 | |
699 | =item Text::Soundex |
700 | |
2e1d04bc |
701 | Implementation of the Soundex Algorithm as Described by Knuth |
f102b883 |
702 | |
703 | =item Text::Wrap |
704 | |
9e107c59 |
705 | Line wrapping to form simple paragraphs |
19799a22 |
706 | |
707 | =item Tie::Array |
708 | |
9e107c59 |
709 | Base class for tied arrays |
19799a22 |
710 | |
711 | =item Tie::Handle |
712 | |
9e107c59 |
713 | Base class definitions for tied handles |
19799a22 |
714 | |
9e107c59 |
715 | =item Tie::Hash |
f102b883 |
716 | |
9e107c59 |
717 | Base class definitions for tied hashes |
f102b883 |
718 | |
719 | =item Tie::RefHash |
720 | |
9e107c59 |
721 | Use references as hash keys |
f102b883 |
722 | |
9e107c59 |
723 | =item Tie::Scalar |
f102b883 |
724 | |
9e107c59 |
725 | Base class definitions for tied scalars |
f102b883 |
726 | |
727 | =item Tie::SubstrHash |
728 | |
19799a22 |
729 | Fixed-table-size, fixed-key-length hashing |
f102b883 |
730 | |
731 | =item Time::Local |
732 | |
9e107c59 |
733 | Efficiently compute time from local and GMT time |
f102b883 |
734 | |
735 | =item Time::gmtime |
736 | |
9e107c59 |
737 | By-name interface to Perl's built-in gmtime() function |
f102b883 |
738 | |
739 | =item Time::localtime |
740 | |
9e107c59 |
741 | By-name interface to Perl's built-in localtime() function |
f102b883 |
742 | |
743 | =item Time::tm |
744 | |
9e107c59 |
745 | Internal object used by Time::gmtime and Time::localtime |
f102b883 |
746 | |
747 | =item UNIVERSAL |
748 | |
9e107c59 |
749 | Base class for ALL classes (blessed references) |
f102b883 |
750 | |
751 | =item User::grent |
752 | |
9e107c59 |
753 | By-name interface to Perl's built-in getgr*() functions |
f102b883 |
754 | |
755 | =item User::pwent |
756 | |
9e107c59 |
757 | By-name interface to Perl's built-in getpw*() functions |
f102b883 |
758 | |
759 | =back |
760 | |
19799a22 |
761 | To find out I<all> modules installed on your system, including |
2e1d04bc |
762 | those without documentation or outside the standard release, |
b1866b2d |
763 | just do this: |
f102b883 |
764 | |
5a964f20 |
765 | % find `perl -e 'print "@INC"'` -name '*.pm' -print |
f102b883 |
766 | |
2e1d04bc |
767 | They should all have their own documentation installed and accessible |
768 | via your system man(1) command. If you do not have a B<find> |
19799a22 |
769 | program, you can use the Perl B<find2perl> program instead, which |
770 | generates Perl code as output you can run through perl. If you |
771 | have a B<man> program but it doesn't find your modules, you'll have |
2e1d04bc |
772 | to fix your manpath. See L<perl> for details. If you have no |
773 | system B<man> command, you might try the B<perldoc> program. |
f102b883 |
774 | |
775 | =head2 Extension Modules |
776 | |
19799a22 |
777 | Extension modules are written in C (or a mix of Perl and C). They |
778 | are usually dynamically loaded into Perl if and when you need them, |
2e1d04bc |
779 | but may also be be linked in statically. Supported extension modules |
19799a22 |
780 | include Socket, Fcntl, and POSIX. |
f102b883 |
781 | |
782 | Many popular C extension modules do not come bundled (at least, not |
19799a22 |
783 | completely) due to their sizes, volatility, or simply lack of time |
784 | for adequate testing and configuration across the multitude of |
785 | platforms on which Perl was beta-tested. You are encouraged to |
786 | look for them on CPAN (described below), or using web search engines |
787 | like Alta Vista or Deja News. |
f102b883 |
788 | |
789 | =head1 CPAN |
790 | |
19799a22 |
791 | CPAN stands for Comprehensive Perl Archive Network; it's a globally |
792 | replicated trove of Perl materials, including documentation, style |
2e1d04bc |
793 | guides, tricks and traps, alternate ports to non-Unix systems and |
19799a22 |
794 | occasional binary distributions for these. Search engines for |
795 | CPAN can be found at http://cpan.perl.com/ and at |
796 | http://theory.uwinnipeg.ca/mod_perl/cpan-search.pl . |
797 | |
798 | Most importantly, CPAN includes around a thousand unbundled modules, |
799 | some of which require a C compiler to build. Major categories of |
800 | modules are: |
f102b883 |
801 | |
165c0277 |
802 | =over |
f102b883 |
803 | |
804 | =item * |
551e1d92 |
805 | |
f102b883 |
806 | Language Extensions and Documentation Tools |
807 | |
808 | =item * |
551e1d92 |
809 | |
f102b883 |
810 | Development Support |
811 | |
812 | =item * |
551e1d92 |
813 | |
f102b883 |
814 | Operating System Interfaces |
815 | |
816 | =item * |
551e1d92 |
817 | |
f102b883 |
818 | Networking, Device Control (modems) and InterProcess Communication |
819 | |
820 | =item * |
551e1d92 |
821 | |
f102b883 |
822 | Data Types and Data Type Utilities |
823 | |
824 | =item * |
551e1d92 |
825 | |
f102b883 |
826 | Database Interfaces |
827 | |
828 | =item * |
551e1d92 |
829 | |
f102b883 |
830 | User Interfaces |
831 | |
832 | =item * |
551e1d92 |
833 | |
f102b883 |
834 | Interfaces to / Emulations of Other Programming Languages |
835 | |
836 | =item * |
551e1d92 |
837 | |
f102b883 |
838 | File Names, File Systems and File Locking (see also File Handles) |
839 | |
840 | =item * |
551e1d92 |
841 | |
f102b883 |
842 | String Processing, Language Text Processing, Parsing, and Searching |
843 | |
844 | =item * |
551e1d92 |
845 | |
f102b883 |
846 | Option, Argument, Parameter, and Configuration File Processing |
847 | |
848 | =item * |
551e1d92 |
849 | |
f102b883 |
850 | Internationalization and Locale |
851 | |
852 | =item * |
551e1d92 |
853 | |
f102b883 |
854 | Authentication, Security, and Encryption |
855 | |
856 | =item * |
551e1d92 |
857 | |
f102b883 |
858 | World Wide Web, HTML, HTTP, CGI, MIME |
859 | |
860 | =item * |
551e1d92 |
861 | |
f102b883 |
862 | Server and Daemon Utilities |
863 | |
864 | =item * |
551e1d92 |
865 | |
f102b883 |
866 | Archiving and Compression |
867 | |
868 | =item * |
551e1d92 |
869 | |
f102b883 |
870 | Images, Pixmap and Bitmap Manipulation, Drawing, and Graphing |
871 | |
872 | =item * |
551e1d92 |
873 | |
f102b883 |
874 | Mail and Usenet News |
875 | |
876 | =item * |
551e1d92 |
877 | |
f102b883 |
878 | Control Flow Utilities (callbacks and exceptions etc) |
879 | |
880 | =item * |
551e1d92 |
881 | |
f102b883 |
882 | File Handle and Input/Output Stream Utilities |
883 | |
884 | =item * |
551e1d92 |
885 | |
f102b883 |
886 | Miscellaneous Modules |
887 | |
888 | =back |
889 | |
19799a22 |
890 | Registered CPAN sites as of this writing include the following. |
f102b883 |
891 | You should try to choose one close to you: |
892 | |
165c0277 |
893 | =over |
f102b883 |
894 | |
19799a22 |
895 | =item Africa |
f102b883 |
896 | |
0974df93 |
897 | South Africa ftp://ftp.is.co.za/programming/perl/CPAN/ |
898 | ftp://ftp.saix.net/pub/CPAN/ |
899 | ftp://ftp.sun.ac.za/CPAN/ |
be94a901 |
900 | ftp://ftpza.co.za/pub/mirrors/cpan/ |
f102b883 |
901 | |
6cecdcac |
902 | |
19799a22 |
903 | =item Asia |
f102b883 |
904 | |
0974df93 |
905 | China ftp://freesoft.cei.gov.cn/pub/languages/perl/CPAN/ |
6cecdcac |
906 | Hong Kong ftp://ftp.pacific.net.hk/pub/mirror/CPAN/ |
0974df93 |
907 | Indonesia ftp://malone.piksi.itb.ac.id/pub/CPAN/ |
908 | Israel ftp://bioinfo.weizmann.ac.il/pub/software/perl/CPAN/ |
909 | Japan ftp://ftp.dti.ad.jp/pub/lang/CPAN/ |
be94a901 |
910 | ftp://ftp.jaist.ac.jp/pub/lang/perl/CPAN/ |
911 | ftp://ftp.lab.kdd.co.jp/lang/perl/CPAN/ |
912 | ftp://ftp.meisei-u.ac.jp/pub/CPAN/ |
19799a22 |
913 | ftp://ftp.ring.gr.jp/pub/lang/perl/CPAN/ |
be94a901 |
914 | ftp://mirror.nucba.ac.jp/mirror/Perl/ |
6cecdcac |
915 | Saudi-Arabia ftp://ftp.isu.net.sa/pub/CPAN/ |
0974df93 |
916 | Singapore ftp://ftp.nus.edu.sg/pub/unix/perl/CPAN/ |
917 | South Korea ftp://ftp.bora.net/pub/CPAN/ |
918 | ftp://ftp.kornet.net/pub/CPAN/ |
be94a901 |
919 | ftp://ftp.nuri.net/pub/CPAN/ |
0974df93 |
920 | Taiwan ftp://coda.nctu.edu.tw/computer-languages/perl/CPAN/ |
921 | ftp://ftp.ee.ncku.edu.tw/pub3/perl/CPAN/ |
be94a901 |
922 | ftp://ftp1.sinica.edu.tw/pub1/perl/CPAN/ |
6cecdcac |
923 | Thailand ftp://ftp.nectec.or.th/pub/mirrors/CPAN/ |
924 | |
f102b883 |
925 | |
19799a22 |
926 | =item Australasia |
f102b883 |
927 | |
0974df93 |
928 | Australia ftp://cpan.topend.com.au/pub/CPAN/ |
6cecdcac |
929 | ftp://ftp.labyrinth.net.au/pub/perl-CPAN/ |
be94a901 |
930 | ftp://ftp.sage-au.org.au/pub/compilers/perl/CPAN/ |
931 | ftp://mirror.aarnet.edu.au/pub/perl/CPAN/ |
0974df93 |
932 | New Zealand ftp://ftp.auckland.ac.nz/pub/perl/CPAN/ |
be94a901 |
933 | ftp://sunsite.net.nz/pub/languages/perl/CPAN/ |
934 | |
6cecdcac |
935 | |
0974df93 |
936 | =item Central America |
be94a901 |
937 | |
0974df93 |
938 | Costa Rica ftp://ftp.ucr.ac.cr/pub/Unix/CPAN/ |
f102b883 |
939 | |
6cecdcac |
940 | |
19799a22 |
941 | =item Europe |
f102b883 |
942 | |
0974df93 |
943 | Austria ftp://ftp.tuwien.ac.at/pub/languages/perl/CPAN/ |
944 | Belgium ftp://ftp.kulnet.kuleuven.ac.be/pub/mirror/CPAN/ |
945 | Bulgaria ftp://ftp.ntrl.net/pub/mirrors/CPAN/ |
946 | Croatia ftp://ftp.linux.hr/pub/CPAN/ |
947 | Czech Republic ftp://ftp.fi.muni.cz/pub/perl/ |
be94a901 |
948 | ftp://sunsite.mff.cuni.cz/Languages/Perl/CPAN/ |
0974df93 |
949 | Denmark ftp://sunsite.auc.dk/pub/languages/perl/CPAN/ |
950 | Estonia ftp://ftp.ut.ee/pub/languages/perl/CPAN/ |
951 | Finland ftp://ftp.funet.fi/pub/languages/perl/CPAN/ |
6cecdcac |
952 | France ftp://ftp.grolier.fr/pub/perl/CPAN/ |
953 | ftp://ftp.lip6.fr/pub/perl/CPAN/ |
be94a901 |
954 | ftp://ftp.oleane.net/pub/mirrors/CPAN/ |
955 | ftp://ftp.pasteur.fr/pub/computing/CPAN/ |
0974df93 |
956 | ftp://ftp.uvsq.fr/pub/perl/CPAN/ |
6cecdcac |
957 | German ftp://ftp.gigabell.net/pub/CPAN/ |
958 | Germany ftp://ftp.archive.de.uu.net/pub/CPAN/ |
959 | ftp://ftp.freenet.de/pub/ftp.cpan.org/pub/ |
960 | ftp://ftp.gmd.de/packages/CPAN/ |
961 | ftp://ftp.gwdg.de/pub/languages/perl/CPAN/ |
2e1d04bc |
962 | |
963 | ftp://ftp.leo.org/pub/comp/general/programming/languages/script/perl/CPAN/ |
6cecdcac |
964 | ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/ |
965 | ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/ |
966 | ftp://ftp.uni-erlangen.de/pub/source/CPAN/ |
967 | ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/ |
0974df93 |
968 | Germany ftp://ftp.archive.de.uu.net/pub/CPAN/ |
6cecdcac |
969 | ftp://ftp.freenet.de/pub/ftp.cpan.org/pub/ |
be94a901 |
970 | ftp://ftp.gmd.de/packages/CPAN/ |
971 | ftp://ftp.gwdg.de/pub/languages/perl/CPAN/ |
2e1d04bc |
972 | |
973 | ftp://ftp.leo.org/pub/comp/general/programming/languages/script/perl/CPAN/ |
be94a901 |
974 | ftp://ftp.mpi-sb.mpg.de/pub/perl/CPAN/ |
975 | ftp://ftp.rz.ruhr-uni-bochum.de/pub/CPAN/ |
976 | ftp://ftp.uni-erlangen.de/pub/source/CPAN/ |
977 | ftp://ftp.uni-hamburg.de/pub/soft/lang/perl/CPAN/ |
0974df93 |
978 | Greece ftp://ftp.ntua.gr/pub/lang/perl/ |
979 | Hungary ftp://ftp.kfki.hu/pub/packages/perl/CPAN/ |
980 | Iceland ftp://ftp.gm.is/pub/CPAN/ |
981 | Ireland ftp://cpan.indigo.ie/pub/CPAN/ |
982 | ftp://sunsite.compapp.dcu.ie/pub/perl/ |
983 | Italy ftp://cis.uniRoma2.it/CPAN/ |
be94a901 |
984 | ftp://ftp.flashnet.it/pub/CPAN/ |
19799a22 |
985 | ftp://ftp.unina.it/pub/Other/CPAN/ |
be94a901 |
986 | ftp://ftp.unipi.it/pub/mirror/perl/CPAN/ |
0974df93 |
987 | Netherlands ftp://ftp.cs.uu.nl/mirror/CPAN/ |
be94a901 |
988 | ftp://ftp.nluug.nl/pub/languages/perl/CPAN/ |
0974df93 |
989 | Norway ftp://ftp.uit.no/pub/languages/perl/cpan/ |
be94a901 |
990 | ftp://sunsite.uio.no/pub/languages/perl/CPAN/ |
6cecdcac |
991 | Poland ftp://ftp.man.torun.pl/pub/CPAN/ |
be94a901 |
992 | ftp://ftp.pk.edu.pl/pub/lang/perl/CPAN/ |
993 | ftp://sunsite.icm.edu.pl/pub/CPAN/ |
0974df93 |
994 | Portugal ftp://ftp.ci.uminho.pt/pub/mirrors/cpan/ |
19799a22 |
995 | ftp://ftp.ist.utl.pt/pub/CPAN/ |
be94a901 |
996 | ftp://ftp.ua.pt/pub/CPAN/ |
6cecdcac |
997 | Romania ftp://ftp.dnttm.ro/pub/CPAN/ |
19799a22 |
998 | Russia ftp://ftp.chg.ru/pub/lang/perl/CPAN/ |
be94a901 |
999 | ftp://ftp.sai.msu.su/pub/lang/perl/CPAN/ |
0974df93 |
1000 | Slovakia ftp://ftp.entry.sk/pub/languages/perl/CPAN/ |
1001 | Slovenia ftp://ftp.arnes.si/software/perl/CPAN/ |
1002 | Spain ftp://ftp.etse.urv.es/pub/perl/ |
be94a901 |
1003 | ftp://ftp.rediris.es/mirror/CPAN/ |
0974df93 |
1004 | Sweden ftp://ftp.sunet.se/pub/lang/perl/CPAN/ |
1005 | Switzerland ftp://sunsite.cnlab-switch.ch/mirror/CPAN/ |
1006 | Turkey ftp://sunsite.bilkent.edu.tr/pub/languages/CPAN/ |
1007 | United Kingdom ftp://ftp.demon.co.uk/pub/mirrors/perl/CPAN/ |
be94a901 |
1008 | ftp://ftp.flirble.org/pub/languages/perl/CPAN/ |
2e1d04bc |
1009 | |
1010 | ftp://ftp.mirror.ac.uk/sites/ftp.funet.fi/pub/languages/perl/CPAN/ |
be94a901 |
1011 | ftp://ftp.plig.org/pub/CPAN/ |
1012 | ftp://sunsite.doc.ic.ac.uk/packages/CPAN/ |
f102b883 |
1013 | |
6cecdcac |
1014 | |
19799a22 |
1015 | =item North America |
f102b883 |
1016 | |
0974df93 |
1017 | Alberta ftp://sunsite.ualberta.ca/pub/Mirror/CPAN/ |
19799a22 |
1018 | California ftp://cpan.nas.nasa.gov/pub/perl/CPAN/ |
0974df93 |
1019 | ftp://cpan.valueclick.com/CPAN/ |
19799a22 |
1020 | ftp://ftp.cdrom.com/pub/perl/CPAN/ |
6cecdcac |
1021 | http://download.sourceforge.net/mirrors/CPAN/ |
0974df93 |
1022 | Colorado ftp://ftp.cs.colorado.edu/pub/perl/CPAN/ |
1023 | Florida ftp://ftp.cise.ufl.edu/pub/perl/CPAN/ |
6cecdcac |
1024 | Georgia ftp://ftp.twoguys.org/CPAN/ |
0974df93 |
1025 | Illinois ftp://uiarchive.uiuc.edu/pub/lang/perl/CPAN/ |
1026 | Indiana ftp://csociety-ftp.ecn.purdue.edu/pub/CPAN/ |
be94a901 |
1027 | ftp://ftp.uwsg.indiana.edu/pub/perl/CPAN/ |
0974df93 |
1028 | Kentucky ftp://ftp.uky.edu/CPAN/ |
1029 | Manitoba ftp://theoryx5.uwinnipeg.ca/pub/CPAN/ |
2e1d04bc |
1030 | Massachusetts |
1031 | ftp://ftp.ccs.neu.edu/net/mirrors/ftp.funet.fi/pub/languages/perl/CPAN/ |
be94a901 |
1032 | ftp://ftp.iguide.com/pub/mirrors/packages/perl/CPAN/ |
19799a22 |
1033 | Mexico ftp://ftp.msg.com.mx/pub/CPAN/ |
0974df93 |
1034 | New York ftp://ftp.deao.net/pub/CPAN/ |
1035 | ftp://ftp.rge.com/pub/languages/perl/ |
0974df93 |
1036 | North Carolina ftp://ftp.duke.edu/pub/perl/ |
6cecdcac |
1037 | Nova Scotia ftp://cpan.chebucto.ns.ca/pub/CPAN/ |
0974df93 |
1038 | Oklahoma ftp://ftp.ou.edu/mirrors/CPAN/ |
19799a22 |
1039 | Ontario ftp://ftp.crc.ca/pub/packages/lang/perl/CPAN/ |
0974df93 |
1040 | Oregon ftp://ftp.orst.edu/pub/packages/CPAN/ |
1041 | Pennsylvania ftp://ftp.epix.net/pub/languages/perl/ |
1042 | Tennessee ftp://ftp.sunsite.utk.edu/pub/CPAN/ |
1043 | Texas ftp://ftp.sedl.org/pub/mirrors/CPAN/ |
6cecdcac |
1044 | ftp://jhcloos.com/pub/mirror/CPAN/ |
0974df93 |
1045 | Utah ftp://mirror.xmission.com/CPAN/ |
1046 | Virginia ftp://ftp.perl.org/pub/perl/CPAN/ |
be94a901 |
1047 | ftp://ruff.cs.jmu.edu/pub/CPAN/ |
19799a22 |
1048 | Washington ftp://ftp-mirror.internap.com/pub/CPAN/ |
6cecdcac |
1049 | ftp://ftp.llarian.net/pub/CPAN/ |
19799a22 |
1050 | ftp://ftp.spu.edu/pub/CPAN/ |
f102b883 |
1051 | |
6cecdcac |
1052 | |
19799a22 |
1053 | =item South America |
f102b883 |
1054 | |
0974df93 |
1055 | Brazil ftp://cpan.if.usp.br/pub/mirror/CPAN/ |
1056 | ftp://ftp.matrix.com.br/pub/perl/ |
6cecdcac |
1057 | Chile ftp://sunsite.dcc.uchile.cl/pub/Lang/PERL/ |
f102b883 |
1058 | |
1059 | =back |
1060 | |
1061 | For an up-to-date listing of CPAN sites, |
6cecdcac |
1062 | see http://www.perl.com/perl/CPAN/SITES or ftp://www.perl.com/CPAN/SITES . |
f102b883 |
1063 | |
1064 | =head1 Modules: Creation, Use, and Abuse |
1065 | |
1066 | (The following section is borrowed directly from Tim Bunce's modules |
1067 | file, available at your nearest CPAN site.) |
1068 | |
1069 | Perl implements a class using a package, but the presence of a |
1070 | package doesn't imply the presence of a class. A package is just a |
1071 | namespace. A class is a package that provides subroutines that can be |
1072 | used as methods. A method is just a subroutine that expects, as its |
1073 | first argument, either the name of a package (for "static" methods), |
1074 | or a reference to something (for "virtual" methods). |
1075 | |
1076 | A module is a file that (by convention) provides a class of the same |
1077 | name (sans the .pm), plus an import method in that class that can be |
1078 | called to fetch exported symbols. This module may implement some of |
1079 | its methods by loading dynamic C or C++ objects, but that should be |
1080 | totally transparent to the user of the module. Likewise, the module |
1081 | might set up an AUTOLOAD function to slurp in subroutine definitions on |
1082 | demand, but this is also transparent. Only the F<.pm> file is required to |
2e1d04bc |
1083 | exist. See L<perlsub>, L<perltoot>, and L<AutoLoader> for details about |
f102b883 |
1084 | the AUTOLOAD mechanism. |
1085 | |
1086 | =head2 Guidelines for Module Creation |
1087 | |
1088 | =over 4 |
1089 | |
1090 | =item Do similar modules already exist in some form? |
1091 | |
1092 | If so, please try to reuse the existing modules either in whole or |
1093 | by inheriting useful features into a new class. If this is not |
1094 | practical try to get together with the module authors to work on |
1095 | extending or enhancing the functionality of the existing modules. |
1096 | A perfect example is the plethora of packages in perl4 for dealing |
1097 | with command line options. |
1098 | |
1099 | If you are writing a module to expand an already existing set of |
1100 | modules, please coordinate with the author of the package. It |
1101 | helps if you follow the same naming scheme and module interaction |
1102 | scheme as the original author. |
1103 | |
1104 | =item Try to design the new module to be easy to extend and reuse. |
1105 | |
9f1b1f2d |
1106 | Try to C<use warnings;> (or C<use warnings qw(...);>). |
1107 | Remember that you can add C<no warnings qw(...);> to individual blocks |
2e1d04bc |
1108 | of code that need less warnings. |
19799a22 |
1109 | |
f102b883 |
1110 | Use blessed references. Use the two argument form of bless to bless |
1111 | into the class name given as the first parameter of the constructor, |
1112 | e.g.,: |
1113 | |
1114 | sub new { |
2e1d04bc |
1115 | my $class = shift; |
1116 | return bless {}, $class; |
f102b883 |
1117 | } |
1118 | |
1119 | or even this if you'd like it to be used as either a static |
1120 | or a virtual method. |
1121 | |
1122 | sub new { |
2e1d04bc |
1123 | my $self = shift; |
1124 | my $class = ref($self) || $self; |
1125 | return bless {}, $class; |
f102b883 |
1126 | } |
1127 | |
1128 | Pass arrays as references so more parameters can be added later |
1129 | (it's also faster). Convert functions into methods where |
1130 | appropriate. Split large methods into smaller more flexible ones. |
1131 | Inherit methods from other modules if appropriate. |
1132 | |
1133 | Avoid class name tests like: C<die "Invalid" unless ref $ref eq 'FOO'>. |
19799a22 |
1134 | Generally you can delete the C<eq 'FOO'> part with no harm at all. |
f102b883 |
1135 | Let the objects look after themselves! Generally, avoid hard-wired |
1136 | class names as far as possible. |
1137 | |
c47ff5f1 |
1138 | Avoid C<< $r->Class::func() >> where using C<@ISA=qw(... Class ...)> and |
1139 | C<< $r->func() >> would work (see L<perlbot> for more details). |
f102b883 |
1140 | |
1141 | Use autosplit so little used or newly added functions won't be a |
5a964f20 |
1142 | burden to programs that don't use them. Add test functions to |
f102b883 |
1143 | the module after __END__ either using AutoSplit or by saying: |
1144 | |
1145 | eval join('',<main::DATA>) || die $@ unless caller(); |
1146 | |
1147 | Does your module pass the 'empty subclass' test? If you say |
19799a22 |
1148 | C<@SUBCLASS::ISA = qw(YOURCLASS);> your applications should be able |
f102b883 |
1149 | to use SUBCLASS in exactly the same way as YOURCLASS. For example, |
1150 | does your application still work if you change: C<$obj = new YOURCLASS;> |
1151 | into: C<$obj = new SUBCLASS;> ? |
1152 | |
1153 | Avoid keeping any state information in your packages. It makes it |
1154 | difficult for multiple other packages to use yours. Keep state |
1155 | information in objects. |
1156 | |
2e1d04bc |
1157 | Always use B<-w>. |
19799a22 |
1158 | |
1159 | Try to C<use strict;> (or C<use strict qw(...);>). |
f102b883 |
1160 | Remember that you can add C<no strict qw(...);> to individual blocks |
2e1d04bc |
1161 | of code that need less strictness. |
19799a22 |
1162 | |
2e1d04bc |
1163 | Always use B<-w>. |
19799a22 |
1164 | |
f102b883 |
1165 | Follow the guidelines in the perlstyle(1) manual. |
1166 | |
19799a22 |
1167 | Always use B<-w>. |
1168 | |
f102b883 |
1169 | =item Some simple style guidelines |
1170 | |
5a964f20 |
1171 | The perlstyle manual supplied with Perl has many helpful points. |
f102b883 |
1172 | |
1173 | Coding style is a matter of personal taste. Many people evolve their |
1174 | style over several years as they learn what helps them write and |
1175 | maintain good code. Here's one set of assorted suggestions that |
1176 | seem to be widely used by experienced developers: |
1177 | |
1178 | Use underscores to separate words. It is generally easier to read |
1179 | $var_names_like_this than $VarNamesLikeThis, especially for |
1180 | non-native speakers of English. It's also a simple rule that works |
1181 | consistently with VAR_NAMES_LIKE_THIS. |
1182 | |
1183 | Package/Module names are an exception to this rule. Perl informally |
1184 | reserves lowercase module names for 'pragma' modules like integer |
1185 | and strict. Other modules normally begin with a capital letter and |
1186 | use mixed case with no underscores (need to be short and portable). |
1187 | |
1188 | You may find it helpful to use letter case to indicate the scope |
1189 | or nature of a variable. For example: |
1190 | |
5a964f20 |
1191 | $ALL_CAPS_HERE constants only (beware clashes with Perl vars) |
f102b883 |
1192 | $Some_Caps_Here package-wide global/static |
1193 | $no_caps_here function scope my() or local() variables |
1194 | |
1195 | Function and method names seem to work best as all lowercase. |
c47ff5f1 |
1196 | e.g., C<< $obj->as_string() >>. |
f102b883 |
1197 | |
1198 | You can use a leading underscore to indicate that a variable or |
1199 | function should not be used outside the package that defined it. |
1200 | |
1201 | =item Select what to export. |
1202 | |
1203 | Do NOT export method names! |
1204 | |
1205 | Do NOT export anything else by default without a good reason! |
1206 | |
1207 | Exports pollute the namespace of the module user. If you must |
1208 | export try to use @EXPORT_OK in preference to @EXPORT and avoid |
1209 | short or common names to reduce the risk of name clashes. |
1210 | |
1211 | Generally anything not exported is still accessible from outside the |
c47ff5f1 |
1212 | module using the ModuleName::item_name (or C<< $blessed_ref->method >>) |
f102b883 |
1213 | syntax. By convention you can use a leading underscore on names to |
1214 | indicate informally that they are 'internal' and not for public use. |
1215 | |
1216 | (It is actually possible to get private functions by saying: |
1217 | C<my $subref = sub { ... }; &$subref;>. But there's no way to call that |
1218 | directly as a method, because a method must have a name in the symbol |
1219 | table.) |
1220 | |
1221 | As a general rule, if the module is trying to be object oriented |
1222 | then export nothing. If it's just a collection of functions then |
1223 | @EXPORT_OK anything but use @EXPORT with caution. |
1224 | |
1225 | =item Select a name for the module. |
1226 | |
1227 | This name should be as descriptive, accurate, and complete as |
1228 | possible. Avoid any risk of ambiguity. Always try to use two or |
1229 | more whole words. Generally the name should reflect what is special |
1230 | about what the module does rather than how it does it. Please use |
1231 | nested module names to group informally or categorize a module. |
1232 | There should be a very good reason for a module not to have a nested name. |
1233 | Module names should begin with a capital letter. |
1234 | |
1235 | Having 57 modules all called Sort will not make life easy for anyone |
1236 | (though having 23 called Sort::Quick is only marginally better :-). |
1237 | Imagine someone trying to install your module alongside many others. |
1238 | If in any doubt ask for suggestions in comp.lang.perl.misc. |
1239 | |
1240 | If you are developing a suite of related modules/classes it's good |
1241 | practice to use nested classes with a common prefix as this will |
1242 | avoid namespace clashes. For example: Xyz::Control, Xyz::View, |
1243 | Xyz::Model etc. Use the modules in this list as a naming guide. |
1244 | |
1245 | If adding a new module to a set, follow the original author's |
1246 | standards for naming modules and the interface to methods in |
1247 | those modules. |
1248 | |
165c0277 |
1249 | If developing modules for private internal or project specific use, |
1250 | that will never be released to the public, then you should ensure |
1251 | that their names will not clash with any future public module. You |
1252 | can do this either by using the reserved Local::* category or by |
1253 | using a category name that includes an underscore like Foo_Corp::*. |
1254 | |
f102b883 |
1255 | To be portable each component of a module name should be limited to |
1256 | 11 characters. If it might be used on MS-DOS then try to ensure each is |
1257 | unique in the first 8 characters. Nested modules make this easier. |
1258 | |
1259 | =item Have you got it right? |
1260 | |
1261 | How do you know that you've made the right decisions? Have you |
1262 | picked an interface design that will cause problems later? Have |
1263 | you picked the most appropriate name? Do you have any questions? |
1264 | |
1265 | The best way to know for sure, and pick up many helpful suggestions, |
1266 | is to ask someone who knows. Comp.lang.perl.misc is read by just about |
1267 | all the people who develop modules and it's the best place to ask. |
1268 | |
1269 | All you need to do is post a short summary of the module, its |
1270 | purpose and interfaces. A few lines on each of the main methods is |
1271 | probably enough. (If you post the whole module it might be ignored |
1272 | by busy people - generally the very people you want to read it!) |
1273 | |
1274 | Don't worry about posting if you can't say when the module will be |
1275 | ready - just say so in the message. It might be worth inviting |
1276 | others to help you, they may be able to complete it for you! |
1277 | |
1278 | =item README and other Additional Files. |
1279 | |
1280 | It's well known that software developers usually fully document the |
1281 | software they write. If, however, the world is in urgent need of |
1282 | your software and there is not enough time to write the full |
1283 | documentation please at least provide a README file containing: |
1284 | |
1285 | =over 10 |
1286 | |
1287 | =item * |
1288 | A description of the module/package/extension etc. |
1289 | |
1290 | =item * |
1291 | A copyright notice - see below. |
1292 | |
1293 | =item * |
1294 | Prerequisites - what else you may need to have. |
1295 | |
1296 | =item * |
1297 | How to build it - possible changes to Makefile.PL etc. |
1298 | |
1299 | =item * |
1300 | How to install it. |
1301 | |
1302 | =item * |
1303 | Recent changes in this release, especially incompatibilities |
1304 | |
1305 | =item * |
1306 | Changes / enhancements you plan to make in the future. |
1307 | |
1308 | =back |
1309 | |
1310 | If the README file seems to be getting too large you may wish to |
1311 | split out some of the sections into separate files: INSTALL, |
1312 | Copying, ToDo etc. |
1313 | |
1314 | =over 4 |
1315 | |
1316 | =item Adding a Copyright Notice. |
1317 | |
1318 | How you choose to license your work is a personal decision. |
1319 | The general mechanism is to assert your Copyright and then make |
1320 | a declaration of how others may copy/use/modify your work. |
1321 | |
1322 | Perl, for example, is supplied with two types of licence: The GNU |
1323 | GPL and The Artistic Licence (see the files README, Copying, and |
1324 | Artistic). Larry has good reasons for NOT just using the GNU GPL. |
1325 | |
1326 | My personal recommendation, out of respect for Larry, Perl, and the |
5a964f20 |
1327 | Perl community at large is to state something simply like: |
f102b883 |
1328 | |
1329 | Copyright (c) 1995 Your Name. All rights reserved. |
1330 | This program is free software; you can redistribute it and/or |
1331 | modify it under the same terms as Perl itself. |
1332 | |
1333 | This statement should at least appear in the README file. You may |
1334 | also wish to include it in a Copying file and your source files. |
1335 | Remember to include the other words in addition to the Copyright. |
1336 | |
1337 | =item Give the module a version/issue/release number. |
1338 | |
1339 | To be fully compatible with the Exporter and MakeMaker modules you |
1340 | should store your module's version number in a non-my package |
1341 | variable called $VERSION. This should be a floating point |
1342 | number with at least two digits after the decimal (i.e., hundredths, |
1343 | e.g, C<$VERSION = "0.01">). Don't use a "1.3.2" style version. |
19799a22 |
1344 | See L<Exporter> for details. |
f102b883 |
1345 | |
1346 | It may be handy to add a function or method to retrieve the number. |
1347 | Use the number in announcements and archive file names when |
1348 | releasing the module (ModuleName-1.02.tar.Z). |
1349 | See perldoc ExtUtils::MakeMaker.pm for details. |
1350 | |
1351 | =item How to release and distribute a module. |
1352 | |
1353 | It's good idea to post an announcement of the availability of your |
1354 | module (or the module itself if small) to the comp.lang.perl.announce |
1355 | Usenet newsgroup. This will at least ensure very wide once-off |
1356 | distribution. |
1357 | |
2e1d04bc |
1358 | If possible, register the module with CPAN. You should |
f102b883 |
1359 | include details of its location in your announcement. |
1360 | |
1361 | Some notes about ftp archives: Please use a long descriptive file |
5a964f20 |
1362 | name that includes the version number. Most incoming directories |
f102b883 |
1363 | will not be readable/listable, i.e., you won't be able to see your |
1364 | file after uploading it. Remember to send your email notification |
1365 | message as soon as possible after uploading else your file may get |
1366 | deleted automatically. Allow time for the file to be processed |
1367 | and/or check the file has been processed before announcing its |
1368 | location. |
1369 | |
1370 | FTP Archives for Perl Modules: |
1371 | |
6cecdcac |
1372 | Follow the instructions and links on: |
f102b883 |
1373 | |
6cecdcac |
1374 | http://www.perl.com/CPAN/modules/00modlist.long.html |
1375 | http://www.perl.com/CPAN/modules/04pause.html |
f102b883 |
1376 | |
1377 | or upload to one of these sites: |
1378 | |
6cecdcac |
1379 | https://pause.kbx.de/pause/ |
1380 | http://pause.perl.org/pause/ |
f102b883 |
1381 | |
6cecdcac |
1382 | and notify <modules@perl.org>. |
f102b883 |
1383 | |
1384 | By using the WWW interface you can ask the Upload Server to mirror |
1385 | your modules from your ftp or WWW site into your own directory on |
1386 | CPAN! |
1387 | |
1388 | Please remember to send me an updated entry for the Module list! |
1389 | |
1390 | =item Take care when changing a released module. |
1391 | |
7b8d334a |
1392 | Always strive to remain compatible with previous released versions. |
1393 | Otherwise try to add a mechanism to revert to the |
19799a22 |
1394 | old behavior if people rely on it. Document incompatible changes. |
f102b883 |
1395 | |
1396 | =back |
1397 | |
1398 | =back |
1399 | |
1400 | =head2 Guidelines for Converting Perl 4 Library Scripts into Modules |
1401 | |
1402 | =over 4 |
1403 | |
1404 | =item There is no requirement to convert anything. |
1405 | |
1406 | If it ain't broke, don't fix it! Perl 4 library scripts should |
1407 | continue to work with no problems. You may need to make some minor |
1408 | changes (like escaping non-array @'s in double quoted strings) but |
1409 | there is no need to convert a .pl file into a Module for just that. |
1410 | |
1411 | =item Consider the implications. |
1412 | |
5a964f20 |
1413 | All Perl applications that make use of the script will need to |
f102b883 |
1414 | be changed (slightly) if the script is converted into a module. Is |
1415 | it worth it unless you plan to make other changes at the same time? |
1416 | |
1417 | =item Make the most of the opportunity. |
1418 | |
1419 | If you are going to convert the script to a module you can use the |
19799a22 |
1420 | opportunity to redesign the interface. The guidelines for module |
1421 | creation above include many of the issues you should consider. |
f102b883 |
1422 | |
1423 | =item The pl2pm utility will get you started. |
1424 | |
1425 | This utility will read *.pl files (given as parameters) and write |
1426 | corresponding *.pm files. The pl2pm utilities does the following: |
1427 | |
1428 | =over 10 |
1429 | |
1430 | =item * |
1431 | Adds the standard Module prologue lines |
1432 | |
1433 | =item * |
1434 | Converts package specifiers from ' to :: |
1435 | |
1436 | =item * |
1437 | Converts die(...) to croak(...) |
1438 | |
1439 | =item * |
1440 | Several other minor changes |
1441 | |
1442 | =back |
1443 | |
1444 | Being a mechanical process pl2pm is not bullet proof. The converted |
1445 | code will need careful checking, especially any package statements. |
1446 | Don't delete the original .pl file till the new .pm one works! |
1447 | |
1448 | =back |
1449 | |
1450 | =head2 Guidelines for Reusing Application Code |
1451 | |
1452 | =over 4 |
1453 | |
551e1d92 |
1454 | =item * |
1455 | |
1456 | Complete applications rarely belong in the Perl Module Library. |
f102b883 |
1457 | |
551e1d92 |
1458 | =item * |
1459 | |
1460 | Many applications contain some Perl code that could be reused. |
f102b883 |
1461 | |
1462 | Help save the world! Share your code in a form that makes it easy |
1463 | to reuse. |
1464 | |
551e1d92 |
1465 | =item * |
1466 | |
1467 | Break-out the reusable code into one or more separate module files. |
f102b883 |
1468 | |
551e1d92 |
1469 | =item * |
1470 | |
1471 | Take the opportunity to reconsider and redesign the interfaces. |
1472 | |
1473 | =item * |
f102b883 |
1474 | |
551e1d92 |
1475 | In some cases the 'application' can then be reduced to a small |
f102b883 |
1476 | |
1477 | fragment of code built on top of the reusable modules. In these cases |
1478 | the application could invoked as: |
1479 | |
5a964f20 |
1480 | % perl -e 'use Module::Name; method(@ARGV)' ... |
f102b883 |
1481 | or |
5a964f20 |
1482 | % perl -mModule::Name ... (in perl5.002 or higher) |
f102b883 |
1483 | |
1484 | =back |
1485 | |
1486 | =head1 NOTE |
1487 | |
1488 | Perl does not enforce private and public parts of its modules as you may |
1489 | have been used to in other languages like C++, Ada, or Modula-17. Perl |
1490 | doesn't have an infatuation with enforced privacy. It would prefer |
1491 | that you stayed out of its living room because you weren't invited, not |
1492 | because it has a shotgun. |
1493 | |
1494 | The module and its user have a contract, part of which is common law, |
1495 | and part of which is "written". Part of the common law contract is |
1496 | that a module doesn't pollute any namespace it wasn't asked to. The |
1497 | written contract for the module (A.K.A. documentation) may make other |
1498 | provisions. But then you know when you C<use RedefineTheWorld> that |
1499 | you're redefining the world and willing to take the consequences. |