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a0d0e21e LW |
1 | =head1 NAME |
2 | ||
3 | perl - Practical Extraction and Report Language | |
4 | ||
5 | =head1 SYNOPSIS | |
6 | ||
19799a22 GS |
7 | B<perl> S<[ B<-sTuU> ]> S<[ B<-hv> ] [ B<-V>[:I<configvar>] ]> |
8 | S<[ B<-cw> ] [ B<-d>[:I<debugger>] ] [ B<-D>[I<number/list>] ]> | |
9 | S<[ B<-pna> ] [ B<-F>I<pattern> ] [ B<-l>[I<octal>] ] [ B<-0>[I<octal>] ]> | |
10 | S<[ B<-I>I<dir> ] [ B<-m>[B<->]I<module> ] [ B<-M>[B<->]I<'module...'> ]> | |
11 | S<[ B<-P> ]> S<[ B<-S> ]> S<[ B<-x>[I<dir>] ]> | |
12 | S<[ B<-i>[I<extension>] ]> S<[ B<-e> I<'command'> ] | |
13 | [ B<--> ] [ I<programfile> ] [ I<argument> ]...> | |
c07a80fd | 14 | |
10151d09 JH |
15 | If you're new to Perl, you should start with L<perlintro>, which is a |
16 | general intro for beginners and provides some background to help you | |
17 | navigate the rest of Perl's extensive documentation. | |
18 | ||
19 | For ease of access, the Perl manual has been split up into several sections. | |
a0d0e21e | 20 | |
fd7b6849 MJD |
21 | =head2 Overview |
22 | ||
fb9cefb4 | 23 | perl Perl overview (this section) |
10151d09 | 24 | perlintro Perl introduction for beginners |
fb9cefb4 | 25 | perltoc Perl documentation table of contents |
760ac839 | 26 | |
fd7b6849 MJD |
27 | =head2 Tutorials |
28 | ||
7a2320f0 AMS |
29 | perlreftut Perl references short introduction |
30 | perldsc Perl data structures intro | |
31 | perllol Perl data structures: arrays of arrays | |
7a2320f0 AMS |
32 | |
33 | perlrequick Perl regular expressions quick start | |
34 | perlretut Perl regular expressions tutorial | |
35 | ||
36 | perlboot Perl OO tutorial for beginners | |
37 | perltoot Perl OO tutorial, part 1 | |
38 | perltooc Perl OO tutorial, part 2 | |
39 | perlbot Perl OO tricks and examples | |
40 | ||
41 | perlstyle Perl style guide | |
42 | ||
43 | perltrap Perl traps for the unwary | |
44 | perldebtut Perl debugging tutorial | |
45 | ||
fd7b6849 MJD |
46 | perlfaq Perl frequently asked questions |
47 | perlfaq1 General Questions About Perl | |
48 | perlfaq2 Obtaining and Learning about Perl | |
49 | perlfaq3 Programming Tools | |
50 | perlfaq4 Data Manipulation | |
51 | perlfaq5 Files and Formats | |
52 | perlfaq6 Regexes | |
53 | perlfaq7 Perl Language Issues | |
54 | perlfaq8 System Interaction | |
55 | perlfaq9 Networking | |
0f542199 | 56 | |
fd7b6849 | 57 | =head2 Reference Manual |
413510b3 | 58 | |
fb9cefb4 | 59 | perlsyn Perl syntax |
4755096e | 60 | perldata Perl data structures |
fb9cefb4 | 61 | perlop Perl operators and precedence |
c2e66d9e | 62 | perlsub Perl subroutines |
fd7b6849 | 63 | perlfunc Perl built-in functions |
413510b3 | 64 | perlopentut Perl open() tutorial |
34babc16 | 65 | perlpacktut Perl open() tutorial |
c2e66d9e | 66 | perlpod Perl plain old documentation |
8a93676d | 67 | perlpodspec Perl plain old documentation format specification |
c2e66d9e GS |
68 | perlrun Perl execution and options |
69 | perldiag Perl diagnostic messages | |
4755096e GS |
70 | perllexwarn Perl warnings and their control |
71 | perldebug Perl debugging | |
fb9cefb4 | 72 | perlvar Perl predefined variables |
4755096e | 73 | perlre Perl regular expressions, the rest of the story |
d396a558 | 74 | perlref Perl references, the rest of the story |
fb9cefb4 | 75 | perlform Perl formats |
d396a558 | 76 | perlobj Perl objects |
d396a558 | 77 | perltie Perl objects hidden behind simple variables |
fd7b6849 | 78 | perldbmfilter Perl DBM filters |
760ac839 | 79 | |
c2e66d9e GS |
80 | perlipc Perl interprocess communication |
81 | perlfork Perl fork() information | |
82 | perlnumber Perl number semantics | |
53d7eaa8 | 83 | |
c2e66d9e | 84 | perlthrtut Perl threads tutorial |
34babc16 | 85 | perlothrtut Old Perl threads tutorial |
c2e66d9e GS |
86 | |
87 | perlport Perl portability guide | |
d396a558 | 88 | perllocale Perl locale support |
07fcf8ff | 89 | perluniintro Perl Unicode introduction |
ba62762e | 90 | perlunicode Perl Unicode support |
d396a558 | 91 | perlebcdic Considerations for running Perl on EBCDIC platforms |
c2e66d9e | 92 | |
d396a558 | 93 | perlsec Perl security |
4755096e | 94 | |
c2e66d9e | 95 | perlmod Perl modules: how they work |
35bf961c JH |
96 | perlmodlib Perl modules: how to write and use |
97 | perlmodstyle Perl modules: how to write modules with style | |
fd7b6849 | 98 | perlmodinstall Perl modules: how to install from CPAN |
c2e66d9e | 99 | perlnewmod Perl modules: preparing a new module for distribution |
760ac839 | 100 | |
fd7b6849 | 101 | perlutil utilities packaged with the Perl distribution |
760ac839 | 102 | |
4755096e | 103 | perlcompile Perl compiler suite intro |
760ac839 | 104 | |
fd7b6849 MJD |
105 | perlfilter Perl source filters |
106 | ||
107 | =head2 Internals and C Language Interface | |
108 | ||
fb9cefb4 | 109 | perlembed Perl ways to embed perl in your C or C++ application |
055fd3a9 | 110 | perldebguts Perl debugging guts and tips |
fb9cefb4 | 111 | perlxstut Perl XS tutorial |
4755096e | 112 | perlxs Perl XS application programming interface |
f40a6c71 | 113 | perlclib Internal replacements for standard C library functions |
fb9cefb4 GS |
114 | perlguts Perl internal functions for those doing extensions |
115 | perlcall Perl calling conventions from C | |
fd7b6849 | 116 | |
954c1994 GS |
117 | perlapi Perl API listing (autogenerated) |
118 | perlintern Perl internal functions (autogenerated) | |
dc5c060f | 119 | perliol C API for Perl's implementation of IO in Layers |
4755096e | 120 | perlapio Perl internal IO abstraction interface |
fd7b6849 | 121 | |
e8cd7eae | 122 | perlhack Perl hackers guide |
4755096e | 123 | |
fd7b6849 MJD |
124 | =head2 Miscellaneous |
125 | ||
126 | perlbook Perl book information | |
fd7b6849 MJD |
127 | perltodo Perl things to do |
128 | ||
fb9cefb4 | 129 | perlhist Perl history records |
4755096e | 130 | perldelta Perl changes since previous version |
245d750e | 131 | perl572delta Perl changes in version 5.7.2 |
1db9e106 JH |
132 | perl571delta Perl changes in version 5.7.1 |
133 | perl570delta Perl changes in version 5.7.0 | |
493a87da | 134 | perl561delta Perl changes in version 5.6.1 |
4755096e GS |
135 | perl56delta Perl changes in version 5.6 |
136 | perl5005delta Perl changes in version 5.005 | |
137 | perl5004delta Perl changes in version 5.004 | |
d516a115 | 138 | |
fd7b6849 MJD |
139 | =head2 Platform-Specific |
140 | ||
37d4d706 | 141 | perlaix Perl notes for AIX |
a83b6f46 JH |
142 | perlamiga Perl notes for AmigaOS |
143 | perlapollo Perl notes for Apollo DomainOS | |
144 | perlbeos Perl notes for BeOS | |
dc5c060f | 145 | perlbs2000 Perl notes for POSIX-BC BS2000 |
a1f19229 | 146 | perlce Perl notes for WinCE |
49877630 | 147 | perlcygwin Perl notes for Cygwin |
245d750e | 148 | perldgux Perl notes for DG/UX |
49877630 | 149 | perldos Perl notes for DOS |
9a997319 | 150 | perlepoc Perl notes for EPOC |
49877630 | 151 | perlhpux Perl notes for HP-UX |
a83b6f46 | 152 | perlhurd Perl notes for Hurd |
da369004 | 153 | perlmachten Perl notes for Power MachTen |
26d9b02f | 154 | perlmacos Perl notes for Mac OS (Classic) |
a83b6f46 | 155 | perlmint Perl notes for MiNT |
ab648d5e | 156 | perlmpeix Perl notes for MPE/iX |
9038e305 | 157 | perlnetware Perl notes for NetWare |
49877630 GS |
158 | perlos2 Perl notes for OS/2 |
159 | perlos390 Perl notes for OS/390 | |
a83b6f46 JH |
160 | perlplan9 Perl notes for Plan 9 |
161 | perlqnx Perl notes for QNX | |
d420ca49 | 162 | perlsolaris Perl notes for Solaris |
772ff3b9 | 163 | perltru64 Perl notes for Tru64 |
91144103 | 164 | perluts Perl notes for UTS |
cbe1151c | 165 | perlvmesa Perl notes for VM/ESA |
49877630 | 166 | perlvms Perl notes for VMS |
9a997319 | 167 | perlvos Perl notes for Stratus VOS |
49877630 GS |
168 | perlwin32 Perl notes for Windows |
169 | ||
a0d0e21e | 170 | |
19799a22 | 171 | By default, the manpages listed above are installed in the |
fc952dec CS |
172 | F</usr/local/man/> directory. |
173 | ||
174 | Extensive additional documentation for Perl modules is available. The | |
175 | default configuration for perl will place this additional documentation | |
176 | in the F</usr/local/lib/perl5/man> directory (or else in the F<man> | |
177 | subdirectory of the Perl library directory). Some of this additional | |
178 | documentation is distributed standard with Perl, but you'll also find | |
179 | documentation for third-party modules there. | |
180 | ||
181 | You should be able to view Perl's documentation with your man(1) | |
182 | program by including the proper directories in the appropriate start-up | |
183 | files, or in the MANPATH environment variable. To find out where the | |
184 | configuration has installed the manpages, type: | |
16d20bd9 | 185 | |
760ac839 | 186 | perl -V:man.dir |
16d20bd9 | 187 | |
fc952dec CS |
188 | If the directories have a common stem, such as F</usr/local/man/man1> |
189 | and F</usr/local/man/man3>, you need only to add that stem | |
190 | (F</usr/local/man>) to your man(1) configuration files or your MANPATH | |
191 | environment variable. If they do not share a stem, you'll have to add | |
192 | both stems. | |
16d20bd9 AD |
193 | |
194 | If that doesn't work for some reason, you can still use the | |
4633a7c4 LW |
195 | supplied F<perldoc> script to view module information. You might |
196 | also look into getting a replacement man program. | |
16d20bd9 | 197 | |
a0d0e21e LW |
198 | If something strange has gone wrong with your program and you're not |
199 | sure where you should look for help, try the B<-w> switch first. It | |
200 | will often point out exactly where the trouble is. | |
201 | ||
202 | =head1 DESCRIPTION | |
203 | ||
5f05dabc | 204 | Perl is a language optimized for scanning arbitrary |
a0d0e21e LW |
205 | text files, extracting information from those text files, and printing |
206 | reports based on that information. It's also a good language for many | |
207 | system management tasks. The language is intended to be practical | |
208 | (easy to use, efficient, complete) rather than beautiful (tiny, | |
94d58c47 | 209 | elegant, minimal). |
210 | ||
aa689395 | 211 | Perl combines (in the author's opinion, anyway) some of the best |
212 | features of C, B<sed>, B<awk>, and B<sh>, so people familiar with | |
213 | those languages should have little difficulty with it. (Language | |
214 | historians will also note some vestiges of B<csh>, Pascal, and even | |
14218588 | 215 | BASIC-PLUS.) Expression syntax corresponds closely to C |
a0d0e21e LW |
216 | expression syntax. Unlike most Unix utilities, Perl does not |
217 | arbitrarily limit the size of your data--if you've got the memory, | |
aa689395 | 218 | Perl can slurp in your whole file as a single string. Recursion is of |
0f31cffe | 219 | unlimited depth. And the tables used by hashes (sometimes called |
aa689395 | 220 | "associative arrays") grow as necessary to prevent degraded |
0f31cffe | 221 | performance. Perl can use sophisticated pattern matching techniques to |
14218588 | 222 | scan large amounts of data quickly. Although optimized for |
aa689395 | 223 | scanning text, Perl can also deal with binary data, and can make dbm |
224 | files look like hashes. Setuid Perl scripts are safer than C programs | |
14218588 | 225 | through a dataflow tracing mechanism that prevents many stupid |
aa689395 | 226 | security holes. |
227 | ||
228 | If you have a problem that would ordinarily use B<sed> or B<awk> or | |
229 | B<sh>, but it exceeds their capabilities or must run a little faster, | |
230 | and you don't want to write the silly thing in C, then Perl may be for | |
231 | you. There are also translators to turn your B<sed> and B<awk> | |
232 | scripts into Perl scripts. | |
a0d0e21e LW |
233 | |
234 | But wait, there's more... | |
235 | ||
19799a22 GS |
236 | Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete |
237 | rewrite that provides the following additional benefits: | |
a0d0e21e | 238 | |
13a2d996 | 239 | =over 4 |
a0d0e21e | 240 | |
551e1d92 RB |
241 | =item * |
242 | ||
243 | modularity and reusability using innumerable modules | |
a0d0e21e | 244 | |
19799a22 | 245 | Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>. |
a0d0e21e | 246 | |
551e1d92 RB |
247 | =item * |
248 | ||
249 | embeddable and extensible | |
a0d0e21e | 250 | |
19799a22 GS |
251 | Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>, |
252 | L<perlguts>, and L<xsubpp>. | |
a0d0e21e | 253 | |
551e1d92 RB |
254 | =item * |
255 | ||
256 | roll-your-own magic variables (including multiple simultaneous DBM implementations) | |
a0d0e21e | 257 | |
19799a22 | 258 | Described in L<perltie> and L<AnyDBM_File>. |
a0d0e21e | 259 | |
551e1d92 RB |
260 | =item * |
261 | ||
262 | subroutines can now be overridden, autoloaded, and prototyped | |
a0d0e21e | 263 | |
19799a22 | 264 | Described in L<perlsub>. |
a0d0e21e | 265 | |
551e1d92 RB |
266 | =item * |
267 | ||
268 | arbitrarily nested data structures and anonymous functions | |
a0d0e21e | 269 | |
19799a22 | 270 | Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>. |
a0d0e21e | 271 | |
551e1d92 RB |
272 | =item * |
273 | ||
274 | object-oriented programming | |
a0d0e21e | 275 | |
f6b3c421 MJD |
276 | Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>, |
277 | and L<perlbot>. | |
a0d0e21e | 278 | |
551e1d92 RB |
279 | =item * |
280 | ||
281 | compilability into C code or Perl bytecode | |
a0d0e21e | 282 | |
19799a22 | 283 | Described in L<B> and L<B::Bytecode>. |
a0d0e21e | 284 | |
551e1d92 RB |
285 | =item * |
286 | ||
287 | support for light-weight processes (threads) | |
a0d0e21e | 288 | |
19799a22 | 289 | Described in L<perlthrtut> and L<Thread>. |
a0d0e21e | 290 | |
551e1d92 RB |
291 | =item * |
292 | ||
293 | support for internationalization, localization, and Unicode | |
a0d0e21e | 294 | |
19799a22 | 295 | Described in L<perllocale> and L<utf8>. |
a0d0e21e | 296 | |
551e1d92 RB |
297 | =item * |
298 | ||
299 | lexical scoping | |
a0d0e21e | 300 | |
19799a22 | 301 | Described in L<perlsub>. |
a0d0e21e | 302 | |
551e1d92 RB |
303 | =item * |
304 | ||
305 | regular expression enhancements | |
a0d0e21e | 306 | |
19799a22 | 307 | Described in L<perlre>, with additional examples in L<perlop>. |
a0d0e21e | 308 | |
551e1d92 RB |
309 | =item * |
310 | ||
311 | enhanced debugger and interactive Perl environment, | |
312 | with integrated editor support | |
a0d0e21e | 313 | |
f6b3c421 | 314 | Described in L<perldebtut>, L<perldebug> and L<perldebguts>. |
a0d0e21e | 315 | |
551e1d92 RB |
316 | =item * |
317 | ||
318 | POSIX 1003.1 compliant library | |
5f05dabc | 319 | |
19799a22 | 320 | Described in L<POSIX>. |
5f05dabc | 321 | |
a0d0e21e LW |
322 | =back |
323 | ||
68dc0745 | 324 | Okay, that's I<definitely> enough hype. |
a0d0e21e | 325 | |
8e465e4e JH |
326 | =head1 AVAILABILITY |
327 | ||
14218588 | 328 | Perl is available for most operating systems, including virtually |
055fd3a9 GS |
329 | all Unix-like platforms. See L<perlport/"Supported Platforms"> |
330 | for a listing. | |
8bc4a6bb | 331 | |
a0d0e21e LW |
332 | =head1 ENVIRONMENT |
333 | ||
1e422769 | 334 | See L<perlrun>. |
a0d0e21e LW |
335 | |
336 | =head1 AUTHOR | |
337 | ||
19799a22 | 338 | Larry Wall <larry@wall.org>, with the help of oodles of other folks. |
a0d0e21e | 339 | |
a99b1639 TP |
340 | If your Perl success stories and testimonials may be of help to others |
341 | who wish to advocate the use of Perl in their applications, | |
342 | or if you wish to simply express your gratitude to Larry and the | |
19799a22 | 343 | Perl developers, please write to perl-thanks@perl.org . |
a99b1639 | 344 | |
a0d0e21e LW |
345 | =head1 FILES |
346 | ||
5f05dabc | 347 | "@INC" locations of perl libraries |
a0d0e21e LW |
348 | |
349 | =head1 SEE ALSO | |
350 | ||
351 | a2p awk to perl translator | |
352 | s2p sed to perl translator | |
353 | ||
f6b3c421 MJD |
354 | http://www.perl.com/ the Perl Home Page |
355 | http://www.cpan.org/ the Comprehensive Perl Archive | |
356 | http://www.perl.org/ Perl Mongers (Perl user groups) | |
19799a22 | 357 | |
a0d0e21e LW |
358 | =head1 DIAGNOSTICS |
359 | ||
9f1b1f2d GS |
360 | The C<use warnings> pragma (and the B<-w> switch) produces some |
361 | lovely diagnostics. | |
a0d0e21e | 362 | |
5a964f20 TC |
363 | See L<perldiag> for explanations of all Perl's diagnostics. The C<use |
364 | diagnostics> pragma automatically turns Perl's normally terse warnings | |
365 | and errors into these longer forms. | |
a0d0e21e LW |
366 | |
367 | Compilation errors will tell you the line number of the error, with an | |
368 | indication of the next token or token type that was to be examined. | |
14218588 | 369 | (In a script passed to Perl via B<-e> switches, each |
a0d0e21e LW |
370 | B<-e> is counted as one line.) |
371 | ||
372 | Setuid scripts have additional constraints that can produce error | |
373 | messages such as "Insecure dependency". See L<perlsec>. | |
374 | ||
375 | Did we mention that you should definitely consider using the B<-w> | |
376 | switch? | |
377 | ||
378 | =head1 BUGS | |
379 | ||
380 | The B<-w> switch is not mandatory. | |
381 | ||
382 | Perl is at the mercy of your machine's definitions of various | |
1b3f7d21 CS |
383 | operations such as type casting, atof(), and floating-point |
384 | output with sprintf(). | |
a0d0e21e | 385 | |
748a9306 | 386 | If your stdio requires a seek or eof between reads and writes on a |
a0d0e21e LW |
387 | particular stream, so does Perl. (This doesn't apply to sysread() |
388 | and syswrite().) | |
389 | ||
390 | While none of the built-in data types have any arbitrary size limits | |
391 | (apart from memory size), there are still a few arbitrary limits: a | |
a30ac152 GS |
392 | given variable name may not be longer than 251 characters. Line numbers |
393 | displayed by diagnostics are internally stored as short integers, | |
394 | so they are limited to a maximum of 65535 (higher numbers usually being | |
395 | affected by wraparound). | |
a0d0e21e | 396 | |
b0607b7a | 397 | You may mail your bug reports (be sure to include full configuration |
19799a22 | 398 | information as output by the myconfig program in the perl source |
7f2de2d2 | 399 | tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded |
055fd3a9 | 400 | in compiling perl, the B<perlbug> script in the F<utils/> subdirectory |
19799a22 | 401 | can be used to help mail in a bug report. |
4633a7c4 | 402 | |
a0d0e21e LW |
403 | Perl actually stands for Pathologically Eclectic Rubbish Lister, but |
404 | don't tell anyone I said that. | |
405 | ||
406 | =head1 NOTES | |
407 | ||
408 | The Perl motto is "There's more than one way to do it." Divining | |
409 | how many more is left as an exercise to the reader. | |
410 | ||
4633a7c4 | 411 | The three principal virtues of a programmer are Laziness, |
a0d0e21e | 412 | Impatience, and Hubris. See the Camel Book for why. |
16d20bd9 | 413 |