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a0d0e21e LW |
1 | =head1 NAME |
2 | ||
3 | perl - Practical Extraction and Report Language | |
4 | ||
5 | =head1 SYNOPSIS | |
6 | ||
df451b2a RGS |
7 | B<perl> S<[ B<-sTtuUWX> ]> |
8 | S<[ B<-hv> ] [ B<-V>[:I<configvar>] ]> | |
9 | S<[ B<-cw> ] [ B<-d>[B<t>][:I<debugger>] ] [ B<-D>[I<number/list>] ]> | |
10 | S<[ B<-pna> ] [ B<-F>I<pattern> ] [ B<-l>[I<octal>] ] [ B<-0>[I<octal/hexadecimal>] ]> | |
11 | S<[ B<-I>I<dir> ] [ B<-m>[B<->]I<module> ] [ B<-M>[B<->]I<'module...'> ] [ B<-f> ]> | |
12 | S<[ B<-A>[I<module>][=I<assertions>] ]> | |
13 | S<[ B<-C [I<number/list>] >]> | |
14 | S<[ B<-P> ]> | |
15 | S<[ B<-S> ]> | |
16 | S<[ B<-x>[I<dir>] ]> | |
17 | S<[ B<-i>[I<extension>] ]> | |
18 | S<[ B<-e> I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...> | |
c07a80fd | 19 | |
10151d09 JH |
20 | If you're new to Perl, you should start with L<perlintro>, which is a |
21 | general intro for beginners and provides some background to help you | |
22 | navigate the rest of Perl's extensive documentation. | |
23 | ||
24 | For ease of access, the Perl manual has been split up into several sections. | |
a0d0e21e | 25 | |
fd7b6849 MJD |
26 | =head2 Overview |
27 | ||
fb9cefb4 | 28 | perl Perl overview (this section) |
10151d09 | 29 | perlintro Perl introduction for beginners |
fb9cefb4 | 30 | perltoc Perl documentation table of contents |
760ac839 | 31 | |
fd7b6849 MJD |
32 | =head2 Tutorials |
33 | ||
7a2320f0 AMS |
34 | perlreftut Perl references short introduction |
35 | perldsc Perl data structures intro | |
36 | perllol Perl data structures: arrays of arrays | |
7a2320f0 | 37 | |
41630250 | 38 | perlrequick Perl regular expressions quick start |
7a2320f0 AMS |
39 | perlretut Perl regular expressions tutorial |
40 | ||
41 | perlboot Perl OO tutorial for beginners | |
42 | perltoot Perl OO tutorial, part 1 | |
43 | perltooc Perl OO tutorial, part 2 | |
44 | perlbot Perl OO tricks and examples | |
45 | ||
46 | perlstyle Perl style guide | |
47 | ||
41630250 | 48 | perlcheat Perl cheat sheet |
7a2320f0 AMS |
49 | perltrap Perl traps for the unwary |
50 | perldebtut Perl debugging tutorial | |
51 | ||
fd7b6849 MJD |
52 | perlfaq Perl frequently asked questions |
53 | perlfaq1 General Questions About Perl | |
54 | perlfaq2 Obtaining and Learning about Perl | |
55 | perlfaq3 Programming Tools | |
56 | perlfaq4 Data Manipulation | |
57 | perlfaq5 Files and Formats | |
58 | perlfaq6 Regexes | |
59 | perlfaq7 Perl Language Issues | |
60 | perlfaq8 System Interaction | |
61 | perlfaq9 Networking | |
0f542199 | 62 | |
fd7b6849 | 63 | =head2 Reference Manual |
413510b3 | 64 | |
fb9cefb4 | 65 | perlsyn Perl syntax |
4755096e | 66 | perldata Perl data structures |
fb9cefb4 | 67 | perlop Perl operators and precedence |
c2e66d9e | 68 | perlsub Perl subroutines |
fd7b6849 | 69 | perlfunc Perl built-in functions |
413510b3 | 70 | perlopentut Perl open() tutorial |
41630250 | 71 | perlpacktut Perl pack() and unpack() tutorial |
c2e66d9e | 72 | perlpod Perl plain old documentation |
41630250 | 73 | perlpodspec Perl plain old documentation format specification |
c2e66d9e GS |
74 | perlrun Perl execution and options |
75 | perldiag Perl diagnostic messages | |
41630250 | 76 | perllexwarn Perl warnings and their control |
4755096e | 77 | perldebug Perl debugging |
fb9cefb4 | 78 | perlvar Perl predefined variables |
4755096e | 79 | perlre Perl regular expressions, the rest of the story |
30487ceb | 80 | perlreref Perl regular expressions quick reference |
d396a558 | 81 | perlref Perl references, the rest of the story |
fb9cefb4 | 82 | perlform Perl formats |
d396a558 | 83 | perlobj Perl objects |
d396a558 | 84 | perltie Perl objects hidden behind simple variables |
fd7b6849 | 85 | perldbmfilter Perl DBM filters |
760ac839 | 86 | |
c2e66d9e GS |
87 | perlipc Perl interprocess communication |
88 | perlfork Perl fork() information | |
89 | perlnumber Perl number semantics | |
53d7eaa8 | 90 | |
c2e66d9e | 91 | perlthrtut Perl threads tutorial |
41630250 | 92 | perlothrtut Old Perl threads tutorial |
c2e66d9e GS |
93 | |
94 | perlport Perl portability guide | |
d396a558 | 95 | perllocale Perl locale support |
07fcf8ff | 96 | perluniintro Perl Unicode introduction |
41630250 | 97 | perlunicode Perl Unicode support |
d396a558 | 98 | perlebcdic Considerations for running Perl on EBCDIC platforms |
c2e66d9e | 99 | |
d396a558 | 100 | perlsec Perl security |
4755096e | 101 | |
c2e66d9e | 102 | perlmod Perl modules: how they work |
35bf961c JH |
103 | perlmodlib Perl modules: how to write and use |
104 | perlmodstyle Perl modules: how to write modules with style | |
fd7b6849 | 105 | perlmodinstall Perl modules: how to install from CPAN |
c2e66d9e | 106 | perlnewmod Perl modules: preparing a new module for distribution |
760ac839 | 107 | |
fd7b6849 | 108 | perlutil utilities packaged with the Perl distribution |
760ac839 | 109 | |
41630250 | 110 | perlcompile Perl compiler suite intro |
760ac839 | 111 | |
fd7b6849 MJD |
112 | perlfilter Perl source filters |
113 | ||
97a1d740 YST |
114 | perlglossary Perl Glossary |
115 | ||
fd7b6849 MJD |
116 | =head2 Internals and C Language Interface |
117 | ||
fb9cefb4 | 118 | perlembed Perl ways to embed perl in your C or C++ application |
41630250 | 119 | perldebguts Perl debugging guts and tips |
fb9cefb4 | 120 | perlxstut Perl XS tutorial |
4755096e | 121 | perlxs Perl XS application programming interface |
f40a6c71 | 122 | perlclib Internal replacements for standard C library functions |
fb9cefb4 GS |
123 | perlguts Perl internal functions for those doing extensions |
124 | perlcall Perl calling conventions from C | |
fd7b6849 | 125 | |
954c1994 GS |
126 | perlapi Perl API listing (autogenerated) |
127 | perlintern Perl internal functions (autogenerated) | |
dc5c060f | 128 | perliol C API for Perl's implementation of IO in Layers |
4755096e | 129 | perlapio Perl internal IO abstraction interface |
fd7b6849 | 130 | |
e8cd7eae | 131 | perlhack Perl hackers guide |
4755096e | 132 | |
fd7b6849 MJD |
133 | =head2 Miscellaneous |
134 | ||
135 | perlbook Perl book information | |
fd7b6849 MJD |
136 | perltodo Perl things to do |
137 | ||
2a551100 JH |
138 | perldoc Look up Perl documentation in Pod format |
139 | ||
fb9cefb4 | 140 | perlhist Perl history records |
4755096e | 141 | perldelta Perl changes since previous version |
6c7deadb | 142 | perl593delta Perl changes in version 5.9.3 |
496c75d0 | 143 | perl592delta Perl changes in version 5.9.2 |
e0eb806d | 144 | perl591delta Perl changes in version 5.9.1 |
1400179b | 145 | perl590delta Perl changes in version 5.9.0 |
c11a53c6 | 146 | perl588delta Perl changes in version 5.8.8 |
315ba985 | 147 | perl587delta Perl changes in version 5.8.7 |
e4bb216d | 148 | perl586delta Perl changes in version 5.8.6 |
07e9b5fe | 149 | perl585delta Perl changes in version 5.8.5 |
5f15c94e | 150 | perl584delta Perl changes in version 5.8.4 |
2e038148 NC |
151 | perl583delta Perl changes in version 5.8.3 |
152 | perl582delta Perl changes in version 5.8.2 | |
b6235c4f | 153 | perl581delta Perl changes in version 5.8.1 |
2e038148 | 154 | perl58delta Perl changes in version 5.8.0 |
77b096b5 | 155 | perl573delta Perl changes in version 5.7.3 |
245d750e | 156 | perl572delta Perl changes in version 5.7.2 |
1db9e106 JH |
157 | perl571delta Perl changes in version 5.7.1 |
158 | perl570delta Perl changes in version 5.7.0 | |
493a87da | 159 | perl561delta Perl changes in version 5.6.1 |
41630250 | 160 | perl56delta Perl changes in version 5.6 |
4755096e GS |
161 | perl5005delta Perl changes in version 5.005 |
162 | perl5004delta Perl changes in version 5.004 | |
d516a115 | 163 | |
2a551100 JH |
164 | perlartistic Perl Artistic License |
165 | perlgpl GNU General Public License | |
166 | ||
d8416318 JH |
167 | =head2 Language-Specific |
168 | ||
169 | perlcn Perl for Simplified Chinese (in EUC-CN) | |
170 | perljp Perl for Japanese (in EUC-JP) | |
171 | perlko Perl for Korean (in EUC-KR) | |
172 | perltw Perl for Traditional Chinese (in Big5) | |
173 | ||
fd7b6849 MJD |
174 | =head2 Platform-Specific |
175 | ||
37d4d706 | 176 | perlaix Perl notes for AIX |
a83b6f46 JH |
177 | perlamiga Perl notes for AmigaOS |
178 | perlapollo Perl notes for Apollo DomainOS | |
179 | perlbeos Perl notes for BeOS | |
dc5c060f | 180 | perlbs2000 Perl notes for POSIX-BC BS2000 |
a1f19229 | 181 | perlce Perl notes for WinCE |
49877630 | 182 | perlcygwin Perl notes for Cygwin |
245d750e | 183 | perldgux Perl notes for DG/UX |
49877630 | 184 | perldos Perl notes for DOS |
9a997319 | 185 | perlepoc Perl notes for EPOC |
41630250 | 186 | perlfreebsd Perl notes for FreeBSD |
49877630 | 187 | perlhpux Perl notes for HP-UX |
a83b6f46 | 188 | perlhurd Perl notes for Hurd |
469e7be4 | 189 | perlirix Perl notes for Irix |
991e8403 | 190 | perllinux Perl notes for Linux |
41630250 | 191 | perlmachten Perl notes for Power MachTen |
26d9b02f | 192 | perlmacos Perl notes for Mac OS (Classic) |
0d53b15f | 193 | perlmacosx Perl notes for Mac OS X |
a83b6f46 | 194 | perlmint Perl notes for MiNT |
ab648d5e | 195 | perlmpeix Perl notes for MPE/iX |
41630250 | 196 | perlnetware Perl notes for NetWare |
b0846812 | 197 | perlopenbsd Perl notes for OpenBSD |
49877630 GS |
198 | perlos2 Perl notes for OS/2 |
199 | perlos390 Perl notes for OS/390 | |
522b859a | 200 | perlos400 Perl notes for OS/400 |
a83b6f46 JH |
201 | perlplan9 Perl notes for Plan 9 |
202 | perlqnx Perl notes for QNX | |
d420ca49 | 203 | perlsolaris Perl notes for Solaris |
27da23d5 | 204 | perlsymbian Perl notes for Symbian |
772ff3b9 | 205 | perltru64 Perl notes for Tru64 |
41630250 | 206 | perluts Perl notes for UTS |
cbe1151c | 207 | perlvmesa Perl notes for VM/ESA |
49877630 | 208 | perlvms Perl notes for VMS |
9a997319 | 209 | perlvos Perl notes for Stratus VOS |
49877630 GS |
210 | perlwin32 Perl notes for Windows |
211 | ||
a0d0e21e | 212 | |
19799a22 | 213 | By default, the manpages listed above are installed in the |
fc952dec CS |
214 | F</usr/local/man/> directory. |
215 | ||
216 | Extensive additional documentation for Perl modules is available. The | |
217 | default configuration for perl will place this additional documentation | |
218 | in the F</usr/local/lib/perl5/man> directory (or else in the F<man> | |
219 | subdirectory of the Perl library directory). Some of this additional | |
220 | documentation is distributed standard with Perl, but you'll also find | |
221 | documentation for third-party modules there. | |
222 | ||
223 | You should be able to view Perl's documentation with your man(1) | |
224 | program by including the proper directories in the appropriate start-up | |
225 | files, or in the MANPATH environment variable. To find out where the | |
226 | configuration has installed the manpages, type: | |
16d20bd9 | 227 | |
760ac839 | 228 | perl -V:man.dir |
16d20bd9 | 229 | |
fc952dec CS |
230 | If the directories have a common stem, such as F</usr/local/man/man1> |
231 | and F</usr/local/man/man3>, you need only to add that stem | |
232 | (F</usr/local/man>) to your man(1) configuration files or your MANPATH | |
233 | environment variable. If they do not share a stem, you'll have to add | |
234 | both stems. | |
16d20bd9 AD |
235 | |
236 | If that doesn't work for some reason, you can still use the | |
4633a7c4 LW |
237 | supplied F<perldoc> script to view module information. You might |
238 | also look into getting a replacement man program. | |
16d20bd9 | 239 | |
a0d0e21e LW |
240 | If something strange has gone wrong with your program and you're not |
241 | sure where you should look for help, try the B<-w> switch first. It | |
242 | will often point out exactly where the trouble is. | |
243 | ||
244 | =head1 DESCRIPTION | |
245 | ||
5f05dabc | 246 | Perl is a language optimized for scanning arbitrary |
a0d0e21e LW |
247 | text files, extracting information from those text files, and printing |
248 | reports based on that information. It's also a good language for many | |
249 | system management tasks. The language is intended to be practical | |
250 | (easy to use, efficient, complete) rather than beautiful (tiny, | |
94d58c47 | 251 | elegant, minimal). |
252 | ||
aa689395 | 253 | Perl combines (in the author's opinion, anyway) some of the best |
254 | features of C, B<sed>, B<awk>, and B<sh>, so people familiar with | |
255 | those languages should have little difficulty with it. (Language | |
256 | historians will also note some vestiges of B<csh>, Pascal, and even | |
14218588 | 257 | BASIC-PLUS.) Expression syntax corresponds closely to C |
a0d0e21e LW |
258 | expression syntax. Unlike most Unix utilities, Perl does not |
259 | arbitrarily limit the size of your data--if you've got the memory, | |
aa689395 | 260 | Perl can slurp in your whole file as a single string. Recursion is of |
0f31cffe | 261 | unlimited depth. And the tables used by hashes (sometimes called |
aa689395 | 262 | "associative arrays") grow as necessary to prevent degraded |
0f31cffe | 263 | performance. Perl can use sophisticated pattern matching techniques to |
14218588 | 264 | scan large amounts of data quickly. Although optimized for |
aa689395 | 265 | scanning text, Perl can also deal with binary data, and can make dbm |
266 | files look like hashes. Setuid Perl scripts are safer than C programs | |
14218588 | 267 | through a dataflow tracing mechanism that prevents many stupid |
aa689395 | 268 | security holes. |
269 | ||
270 | If you have a problem that would ordinarily use B<sed> or B<awk> or | |
271 | B<sh>, but it exceeds their capabilities or must run a little faster, | |
272 | and you don't want to write the silly thing in C, then Perl may be for | |
273 | you. There are also translators to turn your B<sed> and B<awk> | |
274 | scripts into Perl scripts. | |
a0d0e21e LW |
275 | |
276 | But wait, there's more... | |
277 | ||
19799a22 GS |
278 | Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete |
279 | rewrite that provides the following additional benefits: | |
a0d0e21e | 280 | |
13a2d996 | 281 | =over 4 |
a0d0e21e | 282 | |
551e1d92 RB |
283 | =item * |
284 | ||
285 | modularity and reusability using innumerable modules | |
a0d0e21e | 286 | |
19799a22 | 287 | Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>. |
a0d0e21e | 288 | |
551e1d92 RB |
289 | =item * |
290 | ||
291 | embeddable and extensible | |
a0d0e21e | 292 | |
19799a22 GS |
293 | Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>, |
294 | L<perlguts>, and L<xsubpp>. | |
a0d0e21e | 295 | |
551e1d92 RB |
296 | =item * |
297 | ||
63de3cb2 JH |
298 | roll-your-own magic variables (including multiple simultaneous DBM |
299 | implementations) | |
a0d0e21e | 300 | |
19799a22 | 301 | Described in L<perltie> and L<AnyDBM_File>. |
a0d0e21e | 302 | |
551e1d92 RB |
303 | =item * |
304 | ||
305 | subroutines can now be overridden, autoloaded, and prototyped | |
a0d0e21e | 306 | |
19799a22 | 307 | Described in L<perlsub>. |
a0d0e21e | 308 | |
551e1d92 RB |
309 | =item * |
310 | ||
311 | arbitrarily nested data structures and anonymous functions | |
a0d0e21e | 312 | |
19799a22 | 313 | Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>. |
a0d0e21e | 314 | |
551e1d92 RB |
315 | =item * |
316 | ||
317 | object-oriented programming | |
a0d0e21e | 318 | |
f6b3c421 MJD |
319 | Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>, |
320 | and L<perlbot>. | |
a0d0e21e | 321 | |
551e1d92 RB |
322 | =item * |
323 | ||
551e1d92 | 324 | support for light-weight processes (threads) |
a0d0e21e | 325 | |
63de3cb2 | 326 | Described in L<perlthrtut> and L<threads>. |
a0d0e21e | 327 | |
551e1d92 RB |
328 | =item * |
329 | ||
63de3cb2 | 330 | support for Unicode, internationalization, and localization |
a0d0e21e | 331 | |
63de3cb2 | 332 | Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>. |
a0d0e21e | 333 | |
551e1d92 RB |
334 | =item * |
335 | ||
336 | lexical scoping | |
a0d0e21e | 337 | |
19799a22 | 338 | Described in L<perlsub>. |
a0d0e21e | 339 | |
551e1d92 RB |
340 | =item * |
341 | ||
342 | regular expression enhancements | |
a0d0e21e | 343 | |
19799a22 | 344 | Described in L<perlre>, with additional examples in L<perlop>. |
a0d0e21e | 345 | |
551e1d92 RB |
346 | =item * |
347 | ||
348 | enhanced debugger and interactive Perl environment, | |
349 | with integrated editor support | |
a0d0e21e | 350 | |
f6b3c421 | 351 | Described in L<perldebtut>, L<perldebug> and L<perldebguts>. |
a0d0e21e | 352 | |
551e1d92 RB |
353 | =item * |
354 | ||
355 | POSIX 1003.1 compliant library | |
5f05dabc | 356 | |
19799a22 | 357 | Described in L<POSIX>. |
5f05dabc | 358 | |
a0d0e21e LW |
359 | =back |
360 | ||
68dc0745 | 361 | Okay, that's I<definitely> enough hype. |
a0d0e21e | 362 | |
8e465e4e JH |
363 | =head1 AVAILABILITY |
364 | ||
14218588 | 365 | Perl is available for most operating systems, including virtually |
055fd3a9 GS |
366 | all Unix-like platforms. See L<perlport/"Supported Platforms"> |
367 | for a listing. | |
8bc4a6bb | 368 | |
a0d0e21e LW |
369 | =head1 ENVIRONMENT |
370 | ||
1e422769 | 371 | See L<perlrun>. |
a0d0e21e LW |
372 | |
373 | =head1 AUTHOR | |
374 | ||
19799a22 | 375 | Larry Wall <larry@wall.org>, with the help of oodles of other folks. |
a0d0e21e | 376 | |
a99b1639 TP |
377 | If your Perl success stories and testimonials may be of help to others |
378 | who wish to advocate the use of Perl in their applications, | |
379 | or if you wish to simply express your gratitude to Larry and the | |
19799a22 | 380 | Perl developers, please write to perl-thanks@perl.org . |
a99b1639 | 381 | |
a0d0e21e LW |
382 | =head1 FILES |
383 | ||
5f05dabc | 384 | "@INC" locations of perl libraries |
a0d0e21e LW |
385 | |
386 | =head1 SEE ALSO | |
387 | ||
388 | a2p awk to perl translator | |
389 | s2p sed to perl translator | |
390 | ||
c5f69108 | 391 | http://www.perl.org/ the Perl homepage |
da9e6348 | 392 | http://www.perl.com/ Perl articles (O'Reilly) |
f6b3c421 | 393 | http://www.cpan.org/ the Comprehensive Perl Archive |
c5f69108 | 394 | http://www.pm.org/ the Perl Mongers |
19799a22 | 395 | |
a0d0e21e LW |
396 | =head1 DIAGNOSTICS |
397 | ||
9f1b1f2d GS |
398 | The C<use warnings> pragma (and the B<-w> switch) produces some |
399 | lovely diagnostics. | |
a0d0e21e | 400 | |
5a964f20 TC |
401 | See L<perldiag> for explanations of all Perl's diagnostics. The C<use |
402 | diagnostics> pragma automatically turns Perl's normally terse warnings | |
403 | and errors into these longer forms. | |
a0d0e21e LW |
404 | |
405 | Compilation errors will tell you the line number of the error, with an | |
406 | indication of the next token or token type that was to be examined. | |
14218588 | 407 | (In a script passed to Perl via B<-e> switches, each |
a0d0e21e LW |
408 | B<-e> is counted as one line.) |
409 | ||
410 | Setuid scripts have additional constraints that can produce error | |
411 | messages such as "Insecure dependency". See L<perlsec>. | |
412 | ||
413 | Did we mention that you should definitely consider using the B<-w> | |
414 | switch? | |
415 | ||
416 | =head1 BUGS | |
417 | ||
418 | The B<-w> switch is not mandatory. | |
419 | ||
420 | Perl is at the mercy of your machine's definitions of various | |
1b3f7d21 CS |
421 | operations such as type casting, atof(), and floating-point |
422 | output with sprintf(). | |
a0d0e21e | 423 | |
748a9306 | 424 | If your stdio requires a seek or eof between reads and writes on a |
a0d0e21e LW |
425 | particular stream, so does Perl. (This doesn't apply to sysread() |
426 | and syswrite().) | |
427 | ||
428 | While none of the built-in data types have any arbitrary size limits | |
429 | (apart from memory size), there are still a few arbitrary limits: a | |
a30ac152 GS |
430 | given variable name may not be longer than 251 characters. Line numbers |
431 | displayed by diagnostics are internally stored as short integers, | |
432 | so they are limited to a maximum of 65535 (higher numbers usually being | |
433 | affected by wraparound). | |
a0d0e21e | 434 | |
b0607b7a | 435 | You may mail your bug reports (be sure to include full configuration |
19799a22 | 436 | information as output by the myconfig program in the perl source |
7f2de2d2 | 437 | tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded |
055fd3a9 | 438 | in compiling perl, the B<perlbug> script in the F<utils/> subdirectory |
19799a22 | 439 | can be used to help mail in a bug report. |
4633a7c4 | 440 | |
a0d0e21e LW |
441 | Perl actually stands for Pathologically Eclectic Rubbish Lister, but |
442 | don't tell anyone I said that. | |
443 | ||
444 | =head1 NOTES | |
445 | ||
446 | The Perl motto is "There's more than one way to do it." Divining | |
447 | how many more is left as an exercise to the reader. | |
448 | ||
4633a7c4 | 449 | The three principal virtues of a programmer are Laziness, |
a0d0e21e | 450 | Impatience, and Hubris. See the Camel Book for why. |
16d20bd9 | 451 |