Commit | Line | Data |
a0d0e21e |
1 | =head1 NAME |
2 | |
3 | perl - Practical Extraction and Report Language |
4 | |
5 | =head1 SYNOPSIS |
6 | |
19799a22 |
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 | |
4755096e |
15 | For ease of access, the Perl manual has been split up into several sections: |
a0d0e21e |
16 | |
fb9cefb4 |
17 | perl Perl overview (this section) |
fb9cefb4 |
18 | perlfaq Perl frequently asked questions |
19 | perltoc Perl documentation table of contents |
4755096e |
20 | perlbook Perl book information |
760ac839 |
21 | |
fb9cefb4 |
22 | perlsyn Perl syntax |
4755096e |
23 | perldata Perl data structures |
fb9cefb4 |
24 | perlop Perl operators and precedence |
c2e66d9e |
25 | perlsub Perl subroutines |
26 | perlfunc Perl builtin functions |
4755096e |
27 | perlreftut Perl references short introduction |
28 | perldsc Perl data structures intro |
4755096e |
29 | perlrequick Perl regular expressions quick start |
c2e66d9e |
30 | perlpod Perl plain old documentation |
31 | perlstyle Perl style guide |
32 | perltrap Perl traps for the unwary |
4755096e |
33 | |
c2e66d9e |
34 | perlrun Perl execution and options |
35 | perldiag Perl diagnostic messages |
4755096e |
36 | perllexwarn Perl warnings and their control |
10862624 |
37 | perldebtut Perl debugging tutorial |
4755096e |
38 | perldebug Perl debugging |
39 | |
fb9cefb4 |
40 | perlvar Perl predefined variables |
c2e66d9e |
41 | perllol Perl data structures: arrays of arrays |
42 | perlopentut Perl open() tutorial |
43 | perlretut Perl regular expressions tutorial |
2e1d04bc |
44 | |
4755096e |
45 | perlre Perl regular expressions, the rest of the story |
d396a558 |
46 | perlref Perl references, the rest of the story |
47 | |
fb9cefb4 |
48 | perlform Perl formats |
d396a558 |
49 | |
50 | perlboot Perl OO tutorial for beginners |
51 | perltoot Perl OO tutorial, part 1 |
52 | perltootc Perl OO tutorial, part 2 |
53 | perlobj Perl objects |
54 | perlbot Perl OO tricks and examples |
55 | perltie Perl objects hidden behind simple variables |
760ac839 |
56 | |
c2e66d9e |
57 | perlipc Perl interprocess communication |
58 | perlfork Perl fork() information |
59 | perlnumber Perl number semantics |
60 | perlthrtut Perl threads tutorial |
61 | |
62 | perlport Perl portability guide |
d396a558 |
63 | perllocale Perl locale support |
64 | perlunicode Perl unicode support |
65 | perlebcdic Considerations for running Perl on EBCDIC platforms |
c2e66d9e |
66 | |
d396a558 |
67 | perlsec Perl security |
4755096e |
68 | |
c2e66d9e |
69 | perlmod Perl modules: how they work |
70 | perlmodlib Perl modules: how to write and use |
71 | perlmodinstall Perl modules: how to install from CPAN |
72 | perlnewmod Perl modules: preparing a new module for distribution |
760ac839 |
73 | |
4755096e |
74 | perlfaq1 General Questions About Perl |
75 | perlfaq2 Obtaining and Learning about Perl |
76 | perlfaq3 Programming Tools |
77 | perlfaq4 Data Manipulation |
78 | perlfaq5 Files and Formats |
79 | perlfaq6 Regexes |
80 | perlfaq7 Perl Language Issues |
81 | perlfaq8 System Interaction |
82 | perlfaq9 Networking |
760ac839 |
83 | |
4755096e |
84 | perlcompile Perl compiler suite intro |
760ac839 |
85 | |
fb9cefb4 |
86 | perlembed Perl ways to embed perl in your C or C++ application |
055fd3a9 |
87 | perldebguts Perl debugging guts and tips |
fb9cefb4 |
88 | perlxstut Perl XS tutorial |
4755096e |
89 | perlxs Perl XS application programming interface |
3e2f796a |
90 | perlclib Internal replacements for standard C library functions |
fb9cefb4 |
91 | perlguts Perl internal functions for those doing extensions |
92 | perlcall Perl calling conventions from C |
4755096e |
93 | perlutil utilities packaged with the Perl distribution |
94 | perlfilter Perl source filters |
95 | perldbmfilter Perl DBM filters |
954c1994 |
96 | perlapi Perl API listing (autogenerated) |
97 | perlintern Perl internal functions (autogenerated) |
dc5c060f |
98 | perliol C API for Perl's implementation of IO in Layers |
4755096e |
99 | perlapio Perl internal IO abstraction interface |
e50bb9a1 |
100 | perltodo Perl things to do |
e8cd7eae |
101 | perlhack Perl hackers guide |
4755096e |
102 | |
fb9cefb4 |
103 | perlhist Perl history records |
4755096e |
104 | perldelta Perl changes since previous version |
105 | perl56delta Perl changes in version 5.6 |
106 | perl5005delta Perl changes in version 5.005 |
107 | perl5004delta Perl changes in version 5.004 |
d516a115 |
108 | |
37d4d706 |
109 | perlaix Perl notes for AIX |
49877630 |
110 | perlamiga Perl notes for Amiga |
dc5c060f |
111 | perlbs2000 Perl notes for POSIX-BC BS2000 |
49877630 |
112 | perlcygwin Perl notes for Cygwin |
113 | perldos Perl notes for DOS |
9a997319 |
114 | perlepoc Perl notes for EPOC |
49877630 |
115 | perlhpux Perl notes for HP-UX |
da369004 |
116 | perlmachten Perl notes for Power MachTen |
ab648d5e |
117 | perlmpeix Perl notes for MPE/iX |
49877630 |
118 | perlos2 Perl notes for OS/2 |
119 | perlos390 Perl notes for OS/390 |
d420ca49 |
120 | perlsolaris Perl notes for Solaris |
cbe1151c |
121 | perlvmesa Perl notes for VM/ESA |
49877630 |
122 | perlvms Perl notes for VMS |
9a997319 |
123 | perlvos Perl notes for Stratus VOS |
49877630 |
124 | perlwin32 Perl notes for Windows |
125 | |
a0d0e21e |
126 | (If you're intending to read these straight through for the first time, |
127 | the suggested order will tend to reduce the number of forward references.) |
128 | |
19799a22 |
129 | By default, the manpages listed above are installed in the |
fc952dec |
130 | F</usr/local/man/> directory. |
131 | |
132 | Extensive additional documentation for Perl modules is available. The |
133 | default configuration for perl will place this additional documentation |
134 | in the F</usr/local/lib/perl5/man> directory (or else in the F<man> |
135 | subdirectory of the Perl library directory). Some of this additional |
136 | documentation is distributed standard with Perl, but you'll also find |
137 | documentation for third-party modules there. |
138 | |
139 | You should be able to view Perl's documentation with your man(1) |
140 | program by including the proper directories in the appropriate start-up |
141 | files, or in the MANPATH environment variable. To find out where the |
142 | configuration has installed the manpages, type: |
16d20bd9 |
143 | |
760ac839 |
144 | perl -V:man.dir |
16d20bd9 |
145 | |
fc952dec |
146 | If the directories have a common stem, such as F</usr/local/man/man1> |
147 | and F</usr/local/man/man3>, you need only to add that stem |
148 | (F</usr/local/man>) to your man(1) configuration files or your MANPATH |
149 | environment variable. If they do not share a stem, you'll have to add |
150 | both stems. |
16d20bd9 |
151 | |
152 | If that doesn't work for some reason, you can still use the |
4633a7c4 |
153 | supplied F<perldoc> script to view module information. You might |
154 | also look into getting a replacement man program. |
16d20bd9 |
155 | |
a0d0e21e |
156 | If something strange has gone wrong with your program and you're not |
157 | sure where you should look for help, try the B<-w> switch first. It |
158 | will often point out exactly where the trouble is. |
159 | |
160 | =head1 DESCRIPTION |
161 | |
5f05dabc |
162 | Perl is a language optimized for scanning arbitrary |
a0d0e21e |
163 | text files, extracting information from those text files, and printing |
164 | reports based on that information. It's also a good language for many |
165 | system management tasks. The language is intended to be practical |
166 | (easy to use, efficient, complete) rather than beautiful (tiny, |
94d58c47 |
167 | elegant, minimal). |
168 | |
aa689395 |
169 | Perl combines (in the author's opinion, anyway) some of the best |
170 | features of C, B<sed>, B<awk>, and B<sh>, so people familiar with |
171 | those languages should have little difficulty with it. (Language |
172 | historians will also note some vestiges of B<csh>, Pascal, and even |
14218588 |
173 | BASIC-PLUS.) Expression syntax corresponds closely to C |
a0d0e21e |
174 | expression syntax. Unlike most Unix utilities, Perl does not |
175 | arbitrarily limit the size of your data--if you've got the memory, |
aa689395 |
176 | Perl can slurp in your whole file as a single string. Recursion is of |
0f31cffe |
177 | unlimited depth. And the tables used by hashes (sometimes called |
aa689395 |
178 | "associative arrays") grow as necessary to prevent degraded |
0f31cffe |
179 | performance. Perl can use sophisticated pattern matching techniques to |
14218588 |
180 | scan large amounts of data quickly. Although optimized for |
aa689395 |
181 | scanning text, Perl can also deal with binary data, and can make dbm |
182 | files look like hashes. Setuid Perl scripts are safer than C programs |
14218588 |
183 | through a dataflow tracing mechanism that prevents many stupid |
aa689395 |
184 | security holes. |
185 | |
186 | If you have a problem that would ordinarily use B<sed> or B<awk> or |
187 | B<sh>, but it exceeds their capabilities or must run a little faster, |
188 | and you don't want to write the silly thing in C, then Perl may be for |
189 | you. There are also translators to turn your B<sed> and B<awk> |
190 | scripts into Perl scripts. |
a0d0e21e |
191 | |
192 | But wait, there's more... |
193 | |
19799a22 |
194 | Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete |
195 | rewrite that provides the following additional benefits: |
a0d0e21e |
196 | |
13a2d996 |
197 | =over 4 |
a0d0e21e |
198 | |
551e1d92 |
199 | =item * |
200 | |
201 | modularity and reusability using innumerable modules |
a0d0e21e |
202 | |
19799a22 |
203 | Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>. |
a0d0e21e |
204 | |
551e1d92 |
205 | =item * |
206 | |
207 | embeddable and extensible |
a0d0e21e |
208 | |
19799a22 |
209 | Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>, |
210 | L<perlguts>, and L<xsubpp>. |
a0d0e21e |
211 | |
551e1d92 |
212 | =item * |
213 | |
214 | roll-your-own magic variables (including multiple simultaneous DBM implementations) |
a0d0e21e |
215 | |
19799a22 |
216 | Described in L<perltie> and L<AnyDBM_File>. |
a0d0e21e |
217 | |
551e1d92 |
218 | =item * |
219 | |
220 | subroutines can now be overridden, autoloaded, and prototyped |
a0d0e21e |
221 | |
19799a22 |
222 | Described in L<perlsub>. |
a0d0e21e |
223 | |
551e1d92 |
224 | =item * |
225 | |
226 | arbitrarily nested data structures and anonymous functions |
a0d0e21e |
227 | |
19799a22 |
228 | Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>. |
a0d0e21e |
229 | |
551e1d92 |
230 | =item * |
231 | |
232 | object-oriented programming |
a0d0e21e |
233 | |
19799a22 |
234 | Described in L<perlobj>, L<perltoot>, and L<perlbot>. |
a0d0e21e |
235 | |
551e1d92 |
236 | =item * |
237 | |
238 | compilability into C code or Perl bytecode |
a0d0e21e |
239 | |
19799a22 |
240 | Described in L<B> and L<B::Bytecode>. |
a0d0e21e |
241 | |
551e1d92 |
242 | =item * |
243 | |
244 | support for light-weight processes (threads) |
a0d0e21e |
245 | |
19799a22 |
246 | Described in L<perlthrtut> and L<Thread>. |
a0d0e21e |
247 | |
551e1d92 |
248 | =item * |
249 | |
250 | support for internationalization, localization, and Unicode |
a0d0e21e |
251 | |
19799a22 |
252 | Described in L<perllocale> and L<utf8>. |
a0d0e21e |
253 | |
551e1d92 |
254 | =item * |
255 | |
256 | lexical scoping |
a0d0e21e |
257 | |
19799a22 |
258 | Described in L<perlsub>. |
a0d0e21e |
259 | |
551e1d92 |
260 | =item * |
261 | |
262 | regular expression enhancements |
a0d0e21e |
263 | |
19799a22 |
264 | Described in L<perlre>, with additional examples in L<perlop>. |
a0d0e21e |
265 | |
551e1d92 |
266 | =item * |
267 | |
268 | enhanced debugger and interactive Perl environment, |
269 | with integrated editor support |
a0d0e21e |
270 | |
19799a22 |
271 | Described in L<perldebug>. |
a0d0e21e |
272 | |
551e1d92 |
273 | =item * |
274 | |
275 | POSIX 1003.1 compliant library |
5f05dabc |
276 | |
19799a22 |
277 | Described in L<POSIX>. |
5f05dabc |
278 | |
a0d0e21e |
279 | =back |
280 | |
68dc0745 |
281 | Okay, that's I<definitely> enough hype. |
a0d0e21e |
282 | |
8e465e4e |
283 | =head1 AVAILABILITY |
284 | |
14218588 |
285 | Perl is available for most operating systems, including virtually |
055fd3a9 |
286 | all Unix-like platforms. See L<perlport/"Supported Platforms"> |
287 | for a listing. |
8bc4a6bb |
288 | |
a0d0e21e |
289 | =head1 ENVIRONMENT |
290 | |
1e422769 |
291 | See L<perlrun>. |
a0d0e21e |
292 | |
293 | =head1 AUTHOR |
294 | |
19799a22 |
295 | Larry Wall <larry@wall.org>, with the help of oodles of other folks. |
a0d0e21e |
296 | |
a99b1639 |
297 | If your Perl success stories and testimonials may be of help to others |
298 | who wish to advocate the use of Perl in their applications, |
299 | or if you wish to simply express your gratitude to Larry and the |
19799a22 |
300 | Perl developers, please write to perl-thanks@perl.org . |
a99b1639 |
301 | |
a0d0e21e |
302 | =head1 FILES |
303 | |
5f05dabc |
304 | "@INC" locations of perl libraries |
a0d0e21e |
305 | |
306 | =head1 SEE ALSO |
307 | |
308 | a2p awk to perl translator |
309 | s2p sed to perl translator |
310 | |
19799a22 |
311 | http://www.perl.com/ the Perl Home Page |
5a3e7812 |
312 | http://www.perl.com/CPAN the Comprehensive Perl Archive |
19799a22 |
313 | |
a0d0e21e |
314 | =head1 DIAGNOSTICS |
315 | |
9f1b1f2d |
316 | The C<use warnings> pragma (and the B<-w> switch) produces some |
317 | lovely diagnostics. |
a0d0e21e |
318 | |
5a964f20 |
319 | See L<perldiag> for explanations of all Perl's diagnostics. The C<use |
320 | diagnostics> pragma automatically turns Perl's normally terse warnings |
321 | and errors into these longer forms. |
a0d0e21e |
322 | |
323 | Compilation errors will tell you the line number of the error, with an |
324 | indication of the next token or token type that was to be examined. |
14218588 |
325 | (In a script passed to Perl via B<-e> switches, each |
a0d0e21e |
326 | B<-e> is counted as one line.) |
327 | |
328 | Setuid scripts have additional constraints that can produce error |
329 | messages such as "Insecure dependency". See L<perlsec>. |
330 | |
331 | Did we mention that you should definitely consider using the B<-w> |
332 | switch? |
333 | |
334 | =head1 BUGS |
335 | |
336 | The B<-w> switch is not mandatory. |
337 | |
338 | Perl is at the mercy of your machine's definitions of various |
1b3f7d21 |
339 | operations such as type casting, atof(), and floating-point |
340 | output with sprintf(). |
a0d0e21e |
341 | |
748a9306 |
342 | If your stdio requires a seek or eof between reads and writes on a |
a0d0e21e |
343 | particular stream, so does Perl. (This doesn't apply to sysread() |
344 | and syswrite().) |
345 | |
346 | While none of the built-in data types have any arbitrary size limits |
347 | (apart from memory size), there are still a few arbitrary limits: a |
a30ac152 |
348 | given variable name may not be longer than 251 characters. Line numbers |
349 | displayed by diagnostics are internally stored as short integers, |
350 | so they are limited to a maximum of 65535 (higher numbers usually being |
351 | affected by wraparound). |
a0d0e21e |
352 | |
b0607b7a |
353 | You may mail your bug reports (be sure to include full configuration |
19799a22 |
354 | information as output by the myconfig program in the perl source |
7f2de2d2 |
355 | tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded |
055fd3a9 |
356 | in compiling perl, the B<perlbug> script in the F<utils/> subdirectory |
19799a22 |
357 | can be used to help mail in a bug report. |
4633a7c4 |
358 | |
a0d0e21e |
359 | Perl actually stands for Pathologically Eclectic Rubbish Lister, but |
360 | don't tell anyone I said that. |
361 | |
362 | =head1 NOTES |
363 | |
364 | The Perl motto is "There's more than one way to do it." Divining |
365 | how many more is left as an exercise to the reader. |
366 | |
4633a7c4 |
367 | The three principal virtues of a programmer are Laziness, |
a0d0e21e |
368 | Impatience, and Hubris. See the Camel Book for why. |
16d20bd9 |
369 | |