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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 |
f76b0f69 | 65 | perlpacktut Perl pack() and unpack() 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 | |
d8416318 JH |
139 | =head2 Language-Specific |
140 | ||
141 | perlcn Perl for Simplified Chinese (in EUC-CN) | |
142 | perljp Perl for Japanese (in EUC-JP) | |
143 | perlko Perl for Korean (in EUC-KR) | |
144 | perltw Perl for Traditional Chinese (in Big5) | |
145 | ||
fd7b6849 MJD |
146 | =head2 Platform-Specific |
147 | ||
37d4d706 | 148 | perlaix Perl notes for AIX |
a83b6f46 JH |
149 | perlamiga Perl notes for AmigaOS |
150 | perlapollo Perl notes for Apollo DomainOS | |
151 | perlbeos Perl notes for BeOS | |
dc5c060f | 152 | perlbs2000 Perl notes for POSIX-BC BS2000 |
a1f19229 | 153 | perlce Perl notes for WinCE |
49877630 | 154 | perlcygwin Perl notes for Cygwin |
245d750e | 155 | perldgux Perl notes for DG/UX |
49877630 | 156 | perldos Perl notes for DOS |
9a997319 | 157 | perlepoc Perl notes for EPOC |
18a271bd | 158 | perlfreebsd Perl notes for FreeBSD |
49877630 | 159 | perlhpux Perl notes for HP-UX |
a83b6f46 | 160 | perlhurd Perl notes for Hurd |
469e7be4 | 161 | perlirix Perl notes for Irix |
da369004 | 162 | perlmachten Perl notes for Power MachTen |
26d9b02f | 163 | perlmacos Perl notes for Mac OS (Classic) |
a83b6f46 | 164 | perlmint Perl notes for MiNT |
ab648d5e | 165 | perlmpeix Perl notes for MPE/iX |
9038e305 | 166 | perlnetware Perl notes for NetWare |
49877630 GS |
167 | perlos2 Perl notes for OS/2 |
168 | perlos390 Perl notes for OS/390 | |
a83b6f46 JH |
169 | perlplan9 Perl notes for Plan 9 |
170 | perlqnx Perl notes for QNX | |
d420ca49 | 171 | perlsolaris Perl notes for Solaris |
772ff3b9 | 172 | perltru64 Perl notes for Tru64 |
91144103 | 173 | perluts Perl notes for UTS |
cbe1151c | 174 | perlvmesa Perl notes for VM/ESA |
49877630 | 175 | perlvms Perl notes for VMS |
9a997319 | 176 | perlvos Perl notes for Stratus VOS |
49877630 GS |
177 | perlwin32 Perl notes for Windows |
178 | ||
a0d0e21e | 179 | |
19799a22 | 180 | By default, the manpages listed above are installed in the |
fc952dec CS |
181 | F</usr/local/man/> directory. |
182 | ||
183 | Extensive additional documentation for Perl modules is available. The | |
184 | default configuration for perl will place this additional documentation | |
185 | in the F</usr/local/lib/perl5/man> directory (or else in the F<man> | |
186 | subdirectory of the Perl library directory). Some of this additional | |
187 | documentation is distributed standard with Perl, but you'll also find | |
188 | documentation for third-party modules there. | |
189 | ||
190 | You should be able to view Perl's documentation with your man(1) | |
191 | program by including the proper directories in the appropriate start-up | |
192 | files, or in the MANPATH environment variable. To find out where the | |
193 | configuration has installed the manpages, type: | |
16d20bd9 | 194 | |
760ac839 | 195 | perl -V:man.dir |
16d20bd9 | 196 | |
fc952dec CS |
197 | If the directories have a common stem, such as F</usr/local/man/man1> |
198 | and F</usr/local/man/man3>, you need only to add that stem | |
199 | (F</usr/local/man>) to your man(1) configuration files or your MANPATH | |
200 | environment variable. If they do not share a stem, you'll have to add | |
201 | both stems. | |
16d20bd9 AD |
202 | |
203 | If that doesn't work for some reason, you can still use the | |
4633a7c4 LW |
204 | supplied F<perldoc> script to view module information. You might |
205 | also look into getting a replacement man program. | |
16d20bd9 | 206 | |
a0d0e21e LW |
207 | If something strange has gone wrong with your program and you're not |
208 | sure where you should look for help, try the B<-w> switch first. It | |
209 | will often point out exactly where the trouble is. | |
210 | ||
211 | =head1 DESCRIPTION | |
212 | ||
5f05dabc | 213 | Perl is a language optimized for scanning arbitrary |
a0d0e21e LW |
214 | text files, extracting information from those text files, and printing |
215 | reports based on that information. It's also a good language for many | |
216 | system management tasks. The language is intended to be practical | |
217 | (easy to use, efficient, complete) rather than beautiful (tiny, | |
94d58c47 | 218 | elegant, minimal). |
219 | ||
aa689395 | 220 | Perl combines (in the author's opinion, anyway) some of the best |
221 | features of C, B<sed>, B<awk>, and B<sh>, so people familiar with | |
222 | those languages should have little difficulty with it. (Language | |
223 | historians will also note some vestiges of B<csh>, Pascal, and even | |
14218588 | 224 | BASIC-PLUS.) Expression syntax corresponds closely to C |
a0d0e21e LW |
225 | expression syntax. Unlike most Unix utilities, Perl does not |
226 | arbitrarily limit the size of your data--if you've got the memory, | |
aa689395 | 227 | Perl can slurp in your whole file as a single string. Recursion is of |
0f31cffe | 228 | unlimited depth. And the tables used by hashes (sometimes called |
aa689395 | 229 | "associative arrays") grow as necessary to prevent degraded |
0f31cffe | 230 | performance. Perl can use sophisticated pattern matching techniques to |
14218588 | 231 | scan large amounts of data quickly. Although optimized for |
aa689395 | 232 | scanning text, Perl can also deal with binary data, and can make dbm |
233 | files look like hashes. Setuid Perl scripts are safer than C programs | |
14218588 | 234 | through a dataflow tracing mechanism that prevents many stupid |
aa689395 | 235 | security holes. |
236 | ||
237 | If you have a problem that would ordinarily use B<sed> or B<awk> or | |
238 | B<sh>, but it exceeds their capabilities or must run a little faster, | |
239 | and you don't want to write the silly thing in C, then Perl may be for | |
240 | you. There are also translators to turn your B<sed> and B<awk> | |
241 | scripts into Perl scripts. | |
a0d0e21e LW |
242 | |
243 | But wait, there's more... | |
244 | ||
19799a22 GS |
245 | Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete |
246 | rewrite that provides the following additional benefits: | |
a0d0e21e | 247 | |
13a2d996 | 248 | =over 4 |
a0d0e21e | 249 | |
551e1d92 RB |
250 | =item * |
251 | ||
252 | modularity and reusability using innumerable modules | |
a0d0e21e | 253 | |
19799a22 | 254 | Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>. |
a0d0e21e | 255 | |
551e1d92 RB |
256 | =item * |
257 | ||
258 | embeddable and extensible | |
a0d0e21e | 259 | |
19799a22 GS |
260 | Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>, |
261 | L<perlguts>, and L<xsubpp>. | |
a0d0e21e | 262 | |
551e1d92 RB |
263 | =item * |
264 | ||
265 | roll-your-own magic variables (including multiple simultaneous DBM implementations) | |
a0d0e21e | 266 | |
19799a22 | 267 | Described in L<perltie> and L<AnyDBM_File>. |
a0d0e21e | 268 | |
551e1d92 RB |
269 | =item * |
270 | ||
271 | subroutines can now be overridden, autoloaded, and prototyped | |
a0d0e21e | 272 | |
19799a22 | 273 | Described in L<perlsub>. |
a0d0e21e | 274 | |
551e1d92 RB |
275 | =item * |
276 | ||
277 | arbitrarily nested data structures and anonymous functions | |
a0d0e21e | 278 | |
19799a22 | 279 | Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>. |
a0d0e21e | 280 | |
551e1d92 RB |
281 | =item * |
282 | ||
283 | object-oriented programming | |
a0d0e21e | 284 | |
f6b3c421 MJD |
285 | Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>, |
286 | and L<perlbot>. | |
a0d0e21e | 287 | |
551e1d92 RB |
288 | =item * |
289 | ||
290 | compilability into C code or Perl bytecode | |
a0d0e21e | 291 | |
19799a22 | 292 | Described in L<B> and L<B::Bytecode>. |
a0d0e21e | 293 | |
551e1d92 RB |
294 | =item * |
295 | ||
296 | support for light-weight processes (threads) | |
a0d0e21e | 297 | |
19799a22 | 298 | Described in L<perlthrtut> and L<Thread>. |
a0d0e21e | 299 | |
551e1d92 RB |
300 | =item * |
301 | ||
302 | support for internationalization, localization, and Unicode | |
a0d0e21e | 303 | |
19799a22 | 304 | Described in L<perllocale> and L<utf8>. |
a0d0e21e | 305 | |
551e1d92 RB |
306 | =item * |
307 | ||
308 | lexical scoping | |
a0d0e21e | 309 | |
19799a22 | 310 | Described in L<perlsub>. |
a0d0e21e | 311 | |
551e1d92 RB |
312 | =item * |
313 | ||
314 | regular expression enhancements | |
a0d0e21e | 315 | |
19799a22 | 316 | Described in L<perlre>, with additional examples in L<perlop>. |
a0d0e21e | 317 | |
551e1d92 RB |
318 | =item * |
319 | ||
320 | enhanced debugger and interactive Perl environment, | |
321 | with integrated editor support | |
a0d0e21e | 322 | |
f6b3c421 | 323 | Described in L<perldebtut>, L<perldebug> and L<perldebguts>. |
a0d0e21e | 324 | |
551e1d92 RB |
325 | =item * |
326 | ||
327 | POSIX 1003.1 compliant library | |
5f05dabc | 328 | |
19799a22 | 329 | Described in L<POSIX>. |
5f05dabc | 330 | |
a0d0e21e LW |
331 | =back |
332 | ||
68dc0745 | 333 | Okay, that's I<definitely> enough hype. |
a0d0e21e | 334 | |
8e465e4e JH |
335 | =head1 AVAILABILITY |
336 | ||
14218588 | 337 | Perl is available for most operating systems, including virtually |
055fd3a9 GS |
338 | all Unix-like platforms. See L<perlport/"Supported Platforms"> |
339 | for a listing. | |
8bc4a6bb | 340 | |
a0d0e21e LW |
341 | =head1 ENVIRONMENT |
342 | ||
1e422769 | 343 | See L<perlrun>. |
a0d0e21e LW |
344 | |
345 | =head1 AUTHOR | |
346 | ||
19799a22 | 347 | Larry Wall <larry@wall.org>, with the help of oodles of other folks. |
a0d0e21e | 348 | |
a99b1639 TP |
349 | If your Perl success stories and testimonials may be of help to others |
350 | who wish to advocate the use of Perl in their applications, | |
351 | or if you wish to simply express your gratitude to Larry and the | |
19799a22 | 352 | Perl developers, please write to perl-thanks@perl.org . |
a99b1639 | 353 | |
a0d0e21e LW |
354 | =head1 FILES |
355 | ||
5f05dabc | 356 | "@INC" locations of perl libraries |
a0d0e21e LW |
357 | |
358 | =head1 SEE ALSO | |
359 | ||
360 | a2p awk to perl translator | |
361 | s2p sed to perl translator | |
362 | ||
f6b3c421 MJD |
363 | http://www.perl.com/ the Perl Home Page |
364 | http://www.cpan.org/ the Comprehensive Perl Archive | |
365 | http://www.perl.org/ Perl Mongers (Perl user groups) | |
19799a22 | 366 | |
a0d0e21e LW |
367 | =head1 DIAGNOSTICS |
368 | ||
9f1b1f2d GS |
369 | The C<use warnings> pragma (and the B<-w> switch) produces some |
370 | lovely diagnostics. | |
a0d0e21e | 371 | |
5a964f20 TC |
372 | See L<perldiag> for explanations of all Perl's diagnostics. The C<use |
373 | diagnostics> pragma automatically turns Perl's normally terse warnings | |
374 | and errors into these longer forms. | |
a0d0e21e LW |
375 | |
376 | Compilation errors will tell you the line number of the error, with an | |
377 | indication of the next token or token type that was to be examined. | |
14218588 | 378 | (In a script passed to Perl via B<-e> switches, each |
a0d0e21e LW |
379 | B<-e> is counted as one line.) |
380 | ||
381 | Setuid scripts have additional constraints that can produce error | |
382 | messages such as "Insecure dependency". See L<perlsec>. | |
383 | ||
384 | Did we mention that you should definitely consider using the B<-w> | |
385 | switch? | |
386 | ||
387 | =head1 BUGS | |
388 | ||
389 | The B<-w> switch is not mandatory. | |
390 | ||
391 | Perl is at the mercy of your machine's definitions of various | |
1b3f7d21 CS |
392 | operations such as type casting, atof(), and floating-point |
393 | output with sprintf(). | |
a0d0e21e | 394 | |
748a9306 | 395 | If your stdio requires a seek or eof between reads and writes on a |
a0d0e21e LW |
396 | particular stream, so does Perl. (This doesn't apply to sysread() |
397 | and syswrite().) | |
398 | ||
399 | While none of the built-in data types have any arbitrary size limits | |
400 | (apart from memory size), there are still a few arbitrary limits: a | |
a30ac152 GS |
401 | given variable name may not be longer than 251 characters. Line numbers |
402 | displayed by diagnostics are internally stored as short integers, | |
403 | so they are limited to a maximum of 65535 (higher numbers usually being | |
404 | affected by wraparound). | |
a0d0e21e | 405 | |
b0607b7a | 406 | You may mail your bug reports (be sure to include full configuration |
19799a22 | 407 | information as output by the myconfig program in the perl source |
7f2de2d2 | 408 | tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded |
055fd3a9 | 409 | in compiling perl, the B<perlbug> script in the F<utils/> subdirectory |
19799a22 | 410 | can be used to help mail in a bug report. |
4633a7c4 | 411 | |
a0d0e21e LW |
412 | Perl actually stands for Pathologically Eclectic Rubbish Lister, but |
413 | don't tell anyone I said that. | |
414 | ||
415 | =head1 NOTES | |
416 | ||
417 | The Perl motto is "There's more than one way to do it." Divining | |
418 | how many more is left as an exercise to the reader. | |
419 | ||
4633a7c4 | 420 | The three principal virtues of a programmer are Laziness, |
a0d0e21e | 421 | Impatience, and Hubris. See the Camel Book for why. |
16d20bd9 | 422 |