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 |
fb9cefb4 |
90 | perlguts Perl internal functions for those doing extensions |
91 | perlcall Perl calling conventions from C |
4755096e |
92 | perlutil utilities packaged with the Perl distribution |
93 | perlfilter Perl source filters |
94 | perldbmfilter Perl DBM filters |
954c1994 |
95 | perlapi Perl API listing (autogenerated) |
96 | perlintern Perl internal functions (autogenerated) |
4755096e |
97 | perlapio Perl internal IO abstraction interface |
e50bb9a1 |
98 | perltodo Perl things to do |
e8cd7eae |
99 | perlhack Perl hackers guide |
4755096e |
100 | |
fb9cefb4 |
101 | perlhist Perl history records |
4755096e |
102 | perldelta Perl changes since previous version |
103 | perl56delta Perl changes in version 5.6 |
104 | perl5005delta Perl changes in version 5.005 |
105 | perl5004delta Perl changes in version 5.004 |
d516a115 |
106 | |
37d4d706 |
107 | perlaix Perl notes for AIX |
49877630 |
108 | perlamiga Perl notes for Amiga |
109 | perlcygwin Perl notes for Cygwin |
110 | perldos Perl notes for DOS |
9a997319 |
111 | perlepoc Perl notes for EPOC |
49877630 |
112 | perlhpux Perl notes for HP-UX |
da369004 |
113 | perlmachten Perl notes for Power MachTen |
49877630 |
114 | perlos2 Perl notes for OS/2 |
115 | perlos390 Perl notes for OS/390 |
c2e66d9e |
116 | perlposix-bc Perl notes for POSIX-BC |
d420ca49 |
117 | perlsolaris Perl notes for Solaris |
49877630 |
118 | perlvms Perl notes for VMS |
9a997319 |
119 | perlvos Perl notes for Stratus VOS |
49877630 |
120 | perlwin32 Perl notes for Windows |
121 | |
a0d0e21e |
122 | (If you're intending to read these straight through for the first time, |
123 | the suggested order will tend to reduce the number of forward references.) |
124 | |
19799a22 |
125 | By default, the manpages listed above are installed in the |
fc952dec |
126 | F</usr/local/man/> directory. |
127 | |
128 | Extensive additional documentation for Perl modules is available. The |
129 | default configuration for perl will place this additional documentation |
130 | in the F</usr/local/lib/perl5/man> directory (or else in the F<man> |
131 | subdirectory of the Perl library directory). Some of this additional |
132 | documentation is distributed standard with Perl, but you'll also find |
133 | documentation for third-party modules there. |
134 | |
135 | You should be able to view Perl's documentation with your man(1) |
136 | program by including the proper directories in the appropriate start-up |
137 | files, or in the MANPATH environment variable. To find out where the |
138 | configuration has installed the manpages, type: |
16d20bd9 |
139 | |
760ac839 |
140 | perl -V:man.dir |
16d20bd9 |
141 | |
fc952dec |
142 | If the directories have a common stem, such as F</usr/local/man/man1> |
143 | and F</usr/local/man/man3>, you need only to add that stem |
144 | (F</usr/local/man>) to your man(1) configuration files or your MANPATH |
145 | environment variable. If they do not share a stem, you'll have to add |
146 | both stems. |
16d20bd9 |
147 | |
148 | If that doesn't work for some reason, you can still use the |
4633a7c4 |
149 | supplied F<perldoc> script to view module information. You might |
150 | also look into getting a replacement man program. |
16d20bd9 |
151 | |
a0d0e21e |
152 | If something strange has gone wrong with your program and you're not |
153 | sure where you should look for help, try the B<-w> switch first. It |
154 | will often point out exactly where the trouble is. |
155 | |
156 | =head1 DESCRIPTION |
157 | |
5f05dabc |
158 | Perl is a language optimized for scanning arbitrary |
a0d0e21e |
159 | text files, extracting information from those text files, and printing |
160 | reports based on that information. It's also a good language for many |
161 | system management tasks. The language is intended to be practical |
162 | (easy to use, efficient, complete) rather than beautiful (tiny, |
94d58c47 |
163 | elegant, minimal). |
164 | |
aa689395 |
165 | Perl combines (in the author's opinion, anyway) some of the best |
166 | features of C, B<sed>, B<awk>, and B<sh>, so people familiar with |
167 | those languages should have little difficulty with it. (Language |
168 | historians will also note some vestiges of B<csh>, Pascal, and even |
14218588 |
169 | BASIC-PLUS.) Expression syntax corresponds closely to C |
a0d0e21e |
170 | expression syntax. Unlike most Unix utilities, Perl does not |
171 | arbitrarily limit the size of your data--if you've got the memory, |
aa689395 |
172 | Perl can slurp in your whole file as a single string. Recursion is of |
0f31cffe |
173 | unlimited depth. And the tables used by hashes (sometimes called |
aa689395 |
174 | "associative arrays") grow as necessary to prevent degraded |
0f31cffe |
175 | performance. Perl can use sophisticated pattern matching techniques to |
14218588 |
176 | scan large amounts of data quickly. Although optimized for |
aa689395 |
177 | scanning text, Perl can also deal with binary data, and can make dbm |
178 | files look like hashes. Setuid Perl scripts are safer than C programs |
14218588 |
179 | through a dataflow tracing mechanism that prevents many stupid |
aa689395 |
180 | security holes. |
181 | |
182 | If you have a problem that would ordinarily use B<sed> or B<awk> or |
183 | B<sh>, but it exceeds their capabilities or must run a little faster, |
184 | and you don't want to write the silly thing in C, then Perl may be for |
185 | you. There are also translators to turn your B<sed> and B<awk> |
186 | scripts into Perl scripts. |
a0d0e21e |
187 | |
188 | But wait, there's more... |
189 | |
19799a22 |
190 | Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete |
191 | rewrite that provides the following additional benefits: |
a0d0e21e |
192 | |
13a2d996 |
193 | =over 4 |
a0d0e21e |
194 | |
19799a22 |
195 | =item * modularity and reusability using innumerable modules |
a0d0e21e |
196 | |
19799a22 |
197 | Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>. |
a0d0e21e |
198 | |
19799a22 |
199 | =item * embeddable and extensible |
a0d0e21e |
200 | |
19799a22 |
201 | Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>, |
202 | L<perlguts>, and L<xsubpp>. |
a0d0e21e |
203 | |
19799a22 |
204 | =item * roll-your-own magic variables (including multiple simultaneous DBM implementations) |
a0d0e21e |
205 | |
19799a22 |
206 | Described in L<perltie> and L<AnyDBM_File>. |
a0d0e21e |
207 | |
19799a22 |
208 | =item * subroutines can now be overridden, autoloaded, and prototyped |
a0d0e21e |
209 | |
19799a22 |
210 | Described in L<perlsub>. |
a0d0e21e |
211 | |
19799a22 |
212 | =item * arbitrarily nested data structures and anonymous functions |
a0d0e21e |
213 | |
19799a22 |
214 | Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>. |
a0d0e21e |
215 | |
19799a22 |
216 | =item * object-oriented programming |
a0d0e21e |
217 | |
19799a22 |
218 | Described in L<perlobj>, L<perltoot>, and L<perlbot>. |
a0d0e21e |
219 | |
19799a22 |
220 | =item * compilability into C code or Perl bytecode |
a0d0e21e |
221 | |
19799a22 |
222 | Described in L<B> and L<B::Bytecode>. |
a0d0e21e |
223 | |
19799a22 |
224 | =item * support for light-weight processes (threads) |
a0d0e21e |
225 | |
19799a22 |
226 | Described in L<perlthrtut> and L<Thread>. |
a0d0e21e |
227 | |
19799a22 |
228 | =item * support for internationalization, localization, and Unicode |
a0d0e21e |
229 | |
19799a22 |
230 | Described in L<perllocale> and L<utf8>. |
a0d0e21e |
231 | |
19799a22 |
232 | =item * lexical scoping |
a0d0e21e |
233 | |
19799a22 |
234 | Described in L<perlsub>. |
a0d0e21e |
235 | |
19799a22 |
236 | =item * regular expression enhancements |
a0d0e21e |
237 | |
19799a22 |
238 | Described in L<perlre>, with additional examples in L<perlop>. |
a0d0e21e |
239 | |
14218588 |
240 | =item * enhanced debugger and interactive Perl environment, with integrated editor support |
a0d0e21e |
241 | |
19799a22 |
242 | Described in L<perldebug>. |
a0d0e21e |
243 | |
19799a22 |
244 | =item * POSIX 1003.1 compliant library |
5f05dabc |
245 | |
19799a22 |
246 | Described in L<POSIX>. |
5f05dabc |
247 | |
a0d0e21e |
248 | =back |
249 | |
68dc0745 |
250 | Okay, that's I<definitely> enough hype. |
a0d0e21e |
251 | |
8e465e4e |
252 | =head1 AVAILABILITY |
253 | |
14218588 |
254 | Perl is available for most operating systems, including virtually |
055fd3a9 |
255 | all Unix-like platforms. See L<perlport/"Supported Platforms"> |
256 | for a listing. |
8bc4a6bb |
257 | |
a0d0e21e |
258 | =head1 ENVIRONMENT |
259 | |
1e422769 |
260 | See L<perlrun>. |
a0d0e21e |
261 | |
262 | =head1 AUTHOR |
263 | |
19799a22 |
264 | Larry Wall <larry@wall.org>, with the help of oodles of other folks. |
a0d0e21e |
265 | |
a99b1639 |
266 | If your Perl success stories and testimonials may be of help to others |
267 | who wish to advocate the use of Perl in their applications, |
268 | or if you wish to simply express your gratitude to Larry and the |
19799a22 |
269 | Perl developers, please write to perl-thanks@perl.org . |
a99b1639 |
270 | |
a0d0e21e |
271 | =head1 FILES |
272 | |
5f05dabc |
273 | "@INC" locations of perl libraries |
a0d0e21e |
274 | |
275 | =head1 SEE ALSO |
276 | |
277 | a2p awk to perl translator |
278 | s2p sed to perl translator |
279 | |
19799a22 |
280 | http://www.perl.com/ the Perl Home Page |
5a3e7812 |
281 | http://www.perl.com/CPAN the Comprehensive Perl Archive |
19799a22 |
282 | |
a0d0e21e |
283 | =head1 DIAGNOSTICS |
284 | |
9f1b1f2d |
285 | The C<use warnings> pragma (and the B<-w> switch) produces some |
286 | lovely diagnostics. |
a0d0e21e |
287 | |
5a964f20 |
288 | See L<perldiag> for explanations of all Perl's diagnostics. The C<use |
289 | diagnostics> pragma automatically turns Perl's normally terse warnings |
290 | and errors into these longer forms. |
a0d0e21e |
291 | |
292 | Compilation errors will tell you the line number of the error, with an |
293 | indication of the next token or token type that was to be examined. |
14218588 |
294 | (In a script passed to Perl via B<-e> switches, each |
a0d0e21e |
295 | B<-e> is counted as one line.) |
296 | |
297 | Setuid scripts have additional constraints that can produce error |
298 | messages such as "Insecure dependency". See L<perlsec>. |
299 | |
300 | Did we mention that you should definitely consider using the B<-w> |
301 | switch? |
302 | |
303 | =head1 BUGS |
304 | |
305 | The B<-w> switch is not mandatory. |
306 | |
307 | Perl is at the mercy of your machine's definitions of various |
1b3f7d21 |
308 | operations such as type casting, atof(), and floating-point |
309 | output with sprintf(). |
a0d0e21e |
310 | |
748a9306 |
311 | If your stdio requires a seek or eof between reads and writes on a |
a0d0e21e |
312 | particular stream, so does Perl. (This doesn't apply to sysread() |
313 | and syswrite().) |
314 | |
315 | While none of the built-in data types have any arbitrary size limits |
316 | (apart from memory size), there are still a few arbitrary limits: a |
a30ac152 |
317 | given variable name may not be longer than 251 characters. Line numbers |
318 | displayed by diagnostics are internally stored as short integers, |
319 | so they are limited to a maximum of 65535 (higher numbers usually being |
320 | affected by wraparound). |
a0d0e21e |
321 | |
b0607b7a |
322 | You may mail your bug reports (be sure to include full configuration |
19799a22 |
323 | information as output by the myconfig program in the perl source |
7f2de2d2 |
324 | tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded |
055fd3a9 |
325 | in compiling perl, the B<perlbug> script in the F<utils/> subdirectory |
19799a22 |
326 | can be used to help mail in a bug report. |
4633a7c4 |
327 | |
a0d0e21e |
328 | Perl actually stands for Pathologically Eclectic Rubbish Lister, but |
329 | don't tell anyone I said that. |
330 | |
331 | =head1 NOTES |
332 | |
333 | The Perl motto is "There's more than one way to do it." Divining |
334 | how many more is left as an exercise to the reader. |
335 | |
4633a7c4 |
336 | The three principal virtues of a programmer are Laziness, |
a0d0e21e |
337 | Impatience, and Hubris. See the Camel Book for why. |
16d20bd9 |
338 | |