3 perl - The Perl language interpreter
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<-C [I<number/list>] >]>
15 S<[ B<-i>[I<extension>] ]>
16 S<[ [B<-e>|B<-E>] I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...>
20 The F<perldoc> program gives you access to all the documentation that comes
21 with Perl. You can get more documentation, tutorials and community support
22 online at L<http://www.perl.org/>.
24 If you're new to Perl, you should start by running C<perldoc perlintro>,
25 which is a general intro for beginners and provides some background to help
26 you navigate the rest of Perl's extensive documentation. Run C<perldoc
27 perldoc> to learn more things you can do with F<perldoc>.
29 For ease of access, the Perl manual has been split up into several sections.
33 perl Perl overview (this section)
34 perlintro Perl introduction for beginners
35 perltoc Perl documentation table of contents
39 perlreftut Perl references short introduction
40 perldsc Perl data structures intro
41 perllol Perl data structures: arrays of arrays
43 perlrequick Perl regular expressions quick start
44 perlretut Perl regular expressions tutorial
46 perlboot Perl OO tutorial for beginners
47 perltoot Perl OO tutorial, part 1
48 perltooc Perl OO tutorial, part 2
49 perlbot Perl OO tricks and examples
51 perlperf Perl Performance and Optimization Techniques
53 perlstyle Perl style guide
55 perlcheat Perl cheat sheet
56 perltrap Perl traps for the unwary
57 perldebtut Perl debugging tutorial
59 perlfaq Perl frequently asked questions
60 perlfaq1 General Questions About Perl
61 perlfaq2 Obtaining and Learning about Perl
62 perlfaq3 Programming Tools
63 perlfaq4 Data Manipulation
64 perlfaq5 Files and Formats
66 perlfaq7 Perl Language Issues
67 perlfaq8 System Interaction
70 =head2 Reference Manual
73 perldata Perl data structures
74 perlop Perl operators and precedence
75 perlsub Perl subroutines
76 perlfunc Perl built-in functions
77 perlopentut Perl open() tutorial
78 perlpacktut Perl pack() and unpack() tutorial
79 perlpod Perl plain old documentation
80 perlpodspec Perl plain old documentation format specification
81 perlpodstyle Perl POD style guide
82 perlrun Perl execution and options
83 perldiag Perl diagnostic messages
84 perllexwarn Perl warnings and their control
85 perldebug Perl debugging
86 perlvar Perl predefined variables
87 perlre Perl regular expressions, the rest of the story
88 perlrebackslash Perl regular expression backslash sequences
89 perlrecharclass Perl regular expression character classes
90 perlreref Perl regular expressions quick reference
91 perlref Perl references, the rest of the story
94 perltie Perl objects hidden behind simple variables
95 perldbmfilter Perl DBM filters
97 perlipc Perl interprocess communication
98 perlfork Perl fork() information
99 perlnumber Perl number semantics
101 perlthrtut Perl threads tutorial
103 perlport Perl portability guide
104 perllocale Perl locale support
105 perluniintro Perl Unicode introduction
106 perlunicode Perl Unicode support
107 perlunifaq Perl Unicode FAQ
108 perluniprops Index of Unicode Version 5.2.0 properties in Perl
109 perlunitut Perl Unicode tutorial
110 perlebcdic Considerations for running Perl on EBCDIC platforms
112 perlsec Perl security
114 perlmod Perl modules: how they work
115 perlmodlib Perl modules: how to write and use
116 perlmodstyle Perl modules: how to write modules with style
117 perlmodinstall Perl modules: how to install from CPAN
118 perlnewmod Perl modules: preparing a new module for distribution
119 perlpragma Perl modules: writing a user pragma
121 perlutil utilities packaged with the Perl distribution
123 perlcompile Perl compiler suite intro
125 perlfilter Perl source filters
127 perlglossary Perl Glossary
129 =head2 Internals and C Language Interface
131 perlembed Perl ways to embed perl in your C or C++ application
132 perldebguts Perl debugging guts and tips
133 perlxstut Perl XS tutorial
134 perlxs Perl XS application programming interface
135 perlclib Internal replacements for standard C library functions
136 perlguts Perl internal functions for those doing extensions
137 perlcall Perl calling conventions from C
138 perlmroapi Perl method resolution plugin interface
139 perlreapi Perl regular expression plugin interface
140 perlreguts Perl regular expression engine internals
142 perlapi Perl API listing (autogenerated)
143 perlintern Perl internal functions (autogenerated)
144 perliol C API for Perl's implementation of IO in Layers
145 perlapio Perl internal IO abstraction interface
147 perlhack Perl hackers guide
148 perlpolicy Perl development policies
149 perlrepository Perl source repository
153 perlbook Perl book information
154 perlcommunity Perl community information
155 perltodo Perl things to do
157 perldoc Look up Perl documentation in Pod format
159 perlhist Perl history records
160 perldelta Perl changes since previous version
161 perl5136delta Perl changes in version 5.13.6
162 perl5135delta Perl changes in version 5.13.5
163 perl5134delta Perl changes in version 5.13.4
164 perl5133delta Perl changes in version 5.13.3
165 perl5132delta Perl changes in version 5.13.2
166 perl5131delta Perl changes in version 5.13.1
167 perl5130delta Perl changes in version 5.13.0
168 perl5122delta Perl changes in version 5.12.2
169 perl5121delta Perl changes in version 5.12.1
170 perl5120delta Perl changes in version 5.12.0
171 perl5115delta Perl changes in version 5.11.5
172 perl5114delta Perl changes in version 5.11.4
173 perl5113delta Perl changes in version 5.11.3
174 perl5112delta Perl changes in version 5.11.2
175 perl5111delta Perl changes in version 5.11.1
176 perl5110delta Perl changes in version 5.11.0
177 perl5101delta Perl changes in version 5.10.1
178 perl5100delta Perl changes in version 5.10.0
179 perl595delta Perl changes in version 5.9.5
180 perl594delta Perl changes in version 5.9.4
181 perl593delta Perl changes in version 5.9.3
182 perl592delta Perl changes in version 5.9.2
183 perl591delta Perl changes in version 5.9.1
184 perl590delta Perl changes in version 5.9.0
185 perl589delta Perl changes in version 5.8.9
186 perl588delta Perl changes in version 5.8.8
187 perl587delta Perl changes in version 5.8.7
188 perl586delta Perl changes in version 5.8.6
189 perl585delta Perl changes in version 5.8.5
190 perl584delta Perl changes in version 5.8.4
191 perl583delta Perl changes in version 5.8.3
192 perl582delta Perl changes in version 5.8.2
193 perl581delta Perl changes in version 5.8.1
194 perl58delta Perl changes in version 5.8.0
195 perl573delta Perl changes in version 5.7.3
196 perl572delta Perl changes in version 5.7.2
197 perl571delta Perl changes in version 5.7.1
198 perl570delta Perl changes in version 5.7.0
199 perl561delta Perl changes in version 5.6.1
200 perl56delta Perl changes in version 5.6
201 perl5005delta Perl changes in version 5.005
202 perl5004delta Perl changes in version 5.004
204 perlartistic Perl Artistic License
205 perlgpl GNU General Public License
207 =head2 Language-Specific
209 perlcn Perl for Simplified Chinese (in EUC-CN)
210 perljp Perl for Japanese (in EUC-JP)
211 perlko Perl for Korean (in EUC-KR)
212 perltw Perl for Traditional Chinese (in Big5)
214 =head2 Platform-Specific
216 perlaix Perl notes for AIX
217 perlamiga Perl notes for AmigaOS
218 perlapollo Perl notes for Apollo DomainOS
219 perlbeos Perl notes for BeOS
220 perlbs2000 Perl notes for POSIX-BC BS2000
221 perlce Perl notes for WinCE
222 perlcygwin Perl notes for Cygwin
223 perldgux Perl notes for DG/UX
224 perldos Perl notes for DOS
225 perlepoc Perl notes for EPOC
226 perlfreebsd Perl notes for FreeBSD
227 perlhaiku Perl notes for Haiku
228 perlhpux Perl notes for HP-UX
229 perlhurd Perl notes for Hurd
230 perlirix Perl notes for Irix
231 perllinux Perl notes for Linux
232 perlmacos Perl notes for Mac OS (Classic)
233 perlmacosx Perl notes for Mac OS X
234 perlmpeix Perl notes for MPE/iX
235 perlnetware Perl notes for NetWare
236 perlopenbsd Perl notes for OpenBSD
237 perlos2 Perl notes for OS/2
238 perlos390 Perl notes for OS/390
239 perlos400 Perl notes for OS/400
240 perlplan9 Perl notes for Plan 9
241 perlqnx Perl notes for QNX
242 perlriscos Perl notes for RISC OS
243 perlsolaris Perl notes for Solaris
244 perlsymbian Perl notes for Symbian
245 perltru64 Perl notes for Tru64
246 perluts Perl notes for UTS
247 perlvmesa Perl notes for VM/ESA
248 perlvms Perl notes for VMS
249 perlvos Perl notes for Stratus VOS
250 perlwin32 Perl notes for Windows
253 On a Unix-like system, these documentation files will usually also be
254 available as manpages for use with the F<man> program.
256 In general, if something strange has gone wrong with your program and you're
257 not sure where you should look for help, try the B<-w> switch first. It will
258 often point out exactly where the trouble is.
262 Perl officially stands for Practical Extraction and Report Language,
263 except when it doesn't.
265 Perl is a language optimized for scanning arbitrary
266 text files, extracting information from those text files, and printing
267 reports based on that information. It's also a good language for many
268 system management tasks. The language is intended to be practical
269 (easy to use, efficient, complete) rather than beautiful (tiny,
272 Perl combines (in the author's opinion, anyway) some of the best
273 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
274 those languages should have little difficulty with it. (Language
275 historians will also note some vestiges of B<csh>, Pascal, and even
276 BASIC-PLUS.) Expression syntax corresponds closely to C
277 expression syntax. Unlike most Unix utilities, Perl does not
278 arbitrarily limit the size of your data--if you've got the memory,
279 Perl can slurp in your whole file as a single string. Recursion is of
280 unlimited depth. And the tables used by hashes (sometimes called
281 "associative arrays") grow as necessary to prevent degraded
282 performance. Perl can use sophisticated pattern matching techniques to
283 scan large amounts of data quickly. Although optimized for
284 scanning text, Perl can also deal with binary data, and can make dbm
285 files look like hashes. Setuid Perl scripts are safer than C programs
286 through a dataflow tracing mechanism that prevents many stupid
289 If you have a problem that would ordinarily use B<sed> or B<awk> or
290 B<sh>, but it exceeds their capabilities or must run a little faster,
291 and you don't want to write the silly thing in C, then Perl may be for
292 you. There are also translators to turn your B<sed> and B<awk>
293 scripts into Perl scripts.
295 But wait, there's more...
297 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
298 rewrite that provides the following additional benefits:
304 modularity and reusability using innumerable modules
306 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
310 embeddable and extensible
312 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
313 L<perlguts>, and L<xsubpp>.
317 roll-your-own magic variables (including multiple simultaneous DBM
320 Described in L<perltie> and L<AnyDBM_File>.
324 subroutines can now be overridden, autoloaded, and prototyped
326 Described in L<perlsub>.
330 arbitrarily nested data structures and anonymous functions
332 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
336 object-oriented programming
338 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
343 support for light-weight processes (threads)
345 Described in L<perlthrtut> and L<threads>.
349 support for Unicode, internationalization, and localization
351 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
357 Described in L<perlsub>.
361 regular expression enhancements
363 Described in L<perlre>, with additional examples in L<perlop>.
367 enhanced debugger and interactive Perl environment,
368 with integrated editor support
370 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
374 POSIX 1003.1 compliant library
376 Described in L<POSIX>.
380 Okay, that's I<definitely> enough hype.
384 Perl is available for most operating systems, including virtually
385 all Unix-like platforms. See L<perlport/"Supported Platforms">
394 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
396 If your Perl success stories and testimonials may be of help to others
397 who wish to advocate the use of Perl in their applications,
398 or if you wish to simply express your gratitude to Larry and the
399 Perl developers, please write to perl-thanks@perl.org .
403 "@INC" locations of perl libraries
407 a2p awk to perl translator
408 s2p sed to perl translator
410 http://www.perl.org/ the Perl homepage
411 http://www.perl.com/ Perl articles (O'Reilly)
412 http://www.cpan.org/ the Comprehensive Perl Archive
413 http://www.pm.org/ the Perl Mongers
417 The C<use warnings> pragma (and the B<-w> switch) produces some
420 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
421 diagnostics> pragma automatically turns Perl's normally terse warnings
422 and errors into these longer forms.
424 Compilation errors will tell you the line number of the error, with an
425 indication of the next token or token type that was to be examined.
426 (In a script passed to Perl via B<-e> switches, each
427 B<-e> is counted as one line.)
429 Setuid scripts have additional constraints that can produce error
430 messages such as "Insecure dependency". See L<perlsec>.
432 Did we mention that you should definitely consider using the B<-w>
437 The B<-w> switch is not mandatory.
439 Perl is at the mercy of your machine's definitions of various
440 operations such as type casting, atof(), and floating-point
441 output with sprintf().
443 If your stdio requires a seek or eof between reads and writes on a
444 particular stream, so does Perl. (This doesn't apply to sysread()
447 While none of the built-in data types have any arbitrary size limits
448 (apart from memory size), there are still a few arbitrary limits: a
449 given variable name may not be longer than 251 characters. Line numbers
450 displayed by diagnostics are internally stored as short integers,
451 so they are limited to a maximum of 65535 (higher numbers usually being
452 affected by wraparound).
454 You may mail your bug reports (be sure to include full configuration
455 information as output by the myconfig program in the perl source
456 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
457 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
458 can be used to help mail in a bug report.
460 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
461 don't tell anyone I said that.
465 The Perl motto is "There's more than one way to do it." Divining
466 how many more is left as an exercise to the reader.
468 The three principal virtues of a programmer are Laziness,
469 Impatience, and Hubris. See the Camel Book for why.