3 perl - The Perl 5 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 # This section is parsed by Porting/pod_lib.pl for use by pod/buildtoc etc
35 flag =g perluniprops perlmodlib perlapi perlintern
37 flag =ro perlcn perljp perlko perltw
40 path perlfaq.* cpan/perlfaq/lib/
41 path perlglossary cpan/perlfaq/lib/
42 path perlxs(?:tut)? dist/ExtUtils-ParseXS/lib/
43 path perldoc dist/Pod-Perldoc/lib/
45 aux a2p c2ph h2ph h2xs perlbug pl2pm pod2html pod2man s2p splain xsubpp
51 perl Perl overview (this section)
52 perlintro Perl introduction for beginners
53 perltoc Perl documentation table of contents
57 perlreftut Perl references short introduction
58 perldsc Perl data structures intro
59 perllol Perl data structures: arrays of arrays
61 perlrequick Perl regular expressions quick start
62 perlretut Perl regular expressions tutorial
64 perlootut Perl OO tutorial for beginners
66 perlperf Perl Performance and Optimization Techniques
68 perlstyle Perl style guide
70 perlcheat Perl cheat sheet
71 perltrap Perl traps for the unwary
72 perldebtut Perl debugging tutorial
74 perlfaq Perl frequently asked questions
75 perlfaq1 General Questions About Perl
76 perlfaq2 Obtaining and Learning about Perl
77 perlfaq3 Programming Tools
78 perlfaq4 Data Manipulation
79 perlfaq5 Files and Formats
81 perlfaq7 Perl Language Issues
82 perlfaq8 System Interaction
85 =head2 Reference Manual
88 perldata Perl data structures
89 perlop Perl operators and precedence
90 perlsub Perl subroutines
91 perlfunc Perl built-in functions
92 perlopentut Perl open() tutorial
93 perlpacktut Perl pack() and unpack() tutorial
94 perlpod Perl plain old documentation
95 perlpodspec Perl plain old documentation format specification
96 perlpodstyle Perl POD style guide
97 perlrun Perl execution and options
98 perldiag Perl diagnostic messages
99 perllexwarn Perl warnings and their control
100 perldebug Perl debugging
101 perlvar Perl predefined variables
102 perlre Perl regular expressions, the rest of the story
103 perlrebackslash Perl regular expression backslash sequences
104 perlrecharclass Perl regular expression character classes
105 perlreref Perl regular expressions quick reference
106 perlref Perl references, the rest of the story
107 perlform Perl formats
109 perltie Perl objects hidden behind simple variables
110 perldbmfilter Perl DBM filters
112 perlipc Perl interprocess communication
113 perlfork Perl fork() information
114 perlnumber Perl number semantics
116 perlthrtut Perl threads tutorial
118 perlport Perl portability guide
119 perllocale Perl locale support
120 perluniintro Perl Unicode introduction
121 perlunicode Perl Unicode support
122 perlunifaq Perl Unicode FAQ
123 perluniprops Index of Unicode Version 6.0.0 properties in Perl
124 perlunitut Perl Unicode tutorial
125 perlebcdic Considerations for running Perl on EBCDIC platforms
127 perlsec Perl security
129 perlmod Perl modules: how they work
130 perlmodlib Perl modules: how to write and use
131 perlmodstyle Perl modules: how to write modules with style
132 perlmodinstall Perl modules: how to install from CPAN
133 perlnewmod Perl modules: preparing a new module for distribution
134 perlpragma Perl modules: writing a user pragma
136 perlutil utilities packaged with the Perl distribution
138 perlfilter Perl source filters
140 perldtrace Perl's support for DTrace
142 perlglossary Perl Glossary
144 =head2 Internals and C Language Interface
146 perlembed Perl ways to embed perl in your C or C++ application
147 perldebguts Perl debugging guts and tips
148 perlxstut Perl XS tutorial
149 perlxs Perl XS application programming interface
150 perlclib Internal replacements for standard C library functions
151 perlguts Perl internal functions for those doing extensions
152 perlcall Perl calling conventions from C
153 perlmroapi Perl method resolution plugin interface
154 perlreapi Perl regular expression plugin interface
155 perlreguts Perl regular expression engine internals
157 perlapi Perl API listing (autogenerated)
158 perlintern Perl internal functions (autogenerated)
159 perliol C API for Perl's implementation of IO in Layers
160 perlapio Perl internal IO abstraction interface
162 perlhack Perl hackers guide
163 perlsource Guide to the Perl source tree
164 perlinterp Overview of the Perl interpreter source and how it works
165 perlhacktut Walk through the creation of a simple C code patch
166 perlhacktips Tips for Perl core C code hacking
167 perlpolicy Perl development policies
168 perlgit Using git with the Perl repository
172 perlbook Perl book information
173 perlcommunity Perl community information
174 perltodo Perl things to do
176 perldoc Look up Perl documentation in Pod format
178 perlhist Perl history records
179 perldelta Perl changes since previous version
180 perl5156delta Perl changes in version 5.15.6
181 perl5155delta Perl changes in version 5.15.5
182 perl5154delta Perl changes in version 5.15.4
183 perl5153delta Perl changes in version 5.15.3
184 perl5152delta Perl changes in version 5.15.2
185 perl5151delta Perl changes in version 5.15.1
186 perl5150delta Perl changes in version 5.15.0
187 perl5142delta Perl changes in version 5.14.2
188 perl5141delta Perl changes in version 5.14.1
189 perl5140delta Perl changes in version 5.14.0
190 perl5124delta Perl changes in version 5.12.4
191 perl5123delta Perl changes in version 5.12.3
192 perl5122delta Perl changes in version 5.12.2
193 perl5121delta Perl changes in version 5.12.1
194 perl5120delta Perl changes in version 5.12.0
195 perl5101delta Perl changes in version 5.10.1
196 perl5100delta Perl changes in version 5.10.0
197 perl589delta Perl changes in version 5.8.9
198 perl588delta Perl changes in version 5.8.8
199 perl587delta Perl changes in version 5.8.7
200 perl586delta Perl changes in version 5.8.6
201 perl585delta Perl changes in version 5.8.5
202 perl584delta Perl changes in version 5.8.4
203 perl583delta Perl changes in version 5.8.3
204 perl582delta Perl changes in version 5.8.2
205 perl581delta Perl changes in version 5.8.1
206 perl58delta Perl changes in version 5.8.0
207 perl561delta Perl changes in version 5.6.1
208 perl56delta Perl changes in version 5.6
209 perl5005delta Perl changes in version 5.005
210 perl5004delta Perl changes in version 5.004
212 perlexperiment A listing of experimental features in Perl
214 perlartistic Perl Artistic License
215 perlgpl GNU General Public License
217 =head2 Language-Specific
219 =for buildtoc flag +r
221 perlcn Perl for Simplified Chinese (in EUC-CN)
222 perljp Perl for Japanese (in EUC-JP)
223 perlko Perl for Korean (in EUC-KR)
224 perltw Perl for Traditional Chinese (in Big5)
226 =head2 Platform-Specific
228 perlaix Perl notes for AIX
229 perlamiga Perl notes for AmigaOS
230 perlbeos Perl notes for BeOS
231 perlbs2000 Perl notes for POSIX-BC BS2000
232 perlce Perl notes for WinCE
233 perlcygwin Perl notes for Cygwin
234 perldgux Perl notes for DG/UX
235 perldos Perl notes for DOS
236 perlepoc Perl notes for EPOC
237 perlfreebsd Perl notes for FreeBSD
238 perlhaiku Perl notes for Haiku
239 perlhpux Perl notes for HP-UX
240 perlhurd Perl notes for Hurd
241 perlirix Perl notes for Irix
242 perllinux Perl notes for Linux
243 perlmacos Perl notes for Mac OS (Classic)
244 perlmacosx Perl notes for Mac OS X
245 perlmpeix Perl notes for MPE/iX
246 perlnetware Perl notes for NetWare
247 perlopenbsd Perl notes for OpenBSD
248 perlos2 Perl notes for OS/2
249 perlos390 Perl notes for OS/390
250 perlos400 Perl notes for OS/400
251 perlplan9 Perl notes for Plan 9
252 perlqnx Perl notes for QNX
253 perlriscos Perl notes for RISC OS
254 perlsolaris Perl notes for Solaris
255 perlsymbian Perl notes for Symbian
256 perltru64 Perl notes for Tru64
257 perluts Perl notes for UTS
258 perlvmesa Perl notes for VM/ESA
259 perlvms Perl notes for VMS
260 perlvos Perl notes for Stratus VOS
261 perlwin32 Perl notes for Windows
263 =for buildtoc flag -r
265 =head2 Stubs for Deleted Documents
272 =for buildtoc __END__
274 On a Unix-like system, these documentation files will usually also be
275 available as manpages for use with the F<man> program.
277 In general, if something strange has gone wrong with your program and you're
278 not sure where you should look for help, try the B<-w> switch first. It will
279 often point out exactly where the trouble is.
283 Perl officially stands for Practical Extraction and Report Language,
284 except when it doesn't.
286 Perl was originally a language optimized for scanning arbitrary
287 text files, extracting information from those text files, and printing
288 reports based on that information. It quickly became a good language
289 for many system management tasks. Over the years, Perl has grown into
290 a general-purpose programming language. It's widely used for everything
291 from quick "one-liners" to full-scale application development.
293 The language is intended to be practical (easy to use, efficient,
294 complete) rather than beautiful (tiny, elegant, minimal).
296 Perl combines (in the author's opinion, anyway) some of the best
297 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
298 those languages should have little difficulty with it. (Language
299 historians will also note some vestiges of B<csh>, Pascal, and even
300 BASIC-PLUS.) Expression syntax corresponds closely to C
301 expression syntax. Unlike most Unix utilities, Perl does not
302 arbitrarily limit the size of your data--if you've got the memory,
303 Perl can slurp in your whole file as a single string. Recursion is of
304 unlimited depth. And the tables used by hashes (sometimes called
305 "associative arrays") grow as necessary to prevent degraded
306 performance. Perl can use sophisticated pattern matching techniques to
307 scan large amounts of data quickly. Although optimized for
308 scanning text, Perl also has many excellent tools for slicing
309 and dicing binary data.
311 But wait, there's more...
313 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
314 rewrite that provides the following additional benefits:
320 modularity and reusability using innumerable modules
322 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
326 embeddable and extensible
328 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
329 L<perlguts>, and L<xsubpp>.
333 roll-your-own magic variables (including multiple simultaneous DBM
336 Described in L<perltie> and L<AnyDBM_File>.
340 subroutines can now be overridden, autoloaded, and prototyped
342 Described in L<perlsub>.
346 arbitrarily nested data structures and anonymous functions
348 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
352 object-oriented programming
354 Described in L<perlobj> and L<perlootut>.
358 support for light-weight processes (threads)
360 Described in L<perlthrtut> and L<threads>.
364 support for Unicode, internationalization, and localization
366 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
372 Described in L<perlsub>.
376 regular expression enhancements
378 Described in L<perlre>, with additional examples in L<perlop>.
382 enhanced debugger and interactive Perl environment,
383 with integrated editor support
385 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
389 POSIX 1003.1 compliant library
391 Described in L<POSIX>.
395 Okay, that's I<definitely> enough hype.
399 Perl is available for most operating systems, including virtually
400 all Unix-like platforms. See L<perlport/"Supported Platforms">
409 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
411 If your Perl success stories and testimonials may be of help to others
412 who wish to advocate the use of Perl in their applications,
413 or if you wish to simply express your gratitude to Larry and the
414 Perl developers, please write to perl-thanks@perl.org .
418 "@INC" locations of perl libraries
422 http://www.perl.org/ the Perl homepage
423 http://www.perl.com/ Perl articles (O'Reilly)
424 http://www.cpan.org/ the Comprehensive Perl Archive
425 http://www.pm.org/ the Perl Mongers
429 The C<use warnings> pragma (and the B<-w> switch) produces some
432 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
433 diagnostics> pragma automatically turns Perl's normally terse warnings
434 and errors into these longer forms.
436 Compilation errors will tell you the line number of the error, with an
437 indication of the next token or token type that was to be examined.
438 (In a script passed to Perl via B<-e> switches, each
439 B<-e> is counted as one line.)
441 Setuid scripts have additional constraints that can produce error
442 messages such as "Insecure dependency". See L<perlsec>.
444 Did we mention that you should definitely consider using the B<-w>
449 The B<-w> switch is not mandatory.
451 Perl is at the mercy of your machine's definitions of various
452 operations such as type casting, atof(), and floating-point
453 output with sprintf().
455 If your stdio requires a seek or eof between reads and writes on a
456 particular stream, so does Perl. (This doesn't apply to sysread()
459 While none of the built-in data types have any arbitrary size limits
460 (apart from memory size), there are still a few arbitrary limits: a
461 given variable name may not be longer than 251 characters. Line numbers
462 displayed by diagnostics are internally stored as short integers,
463 so they are limited to a maximum of 65535 (higher numbers usually being
464 affected by wraparound).
466 You may mail your bug reports (be sure to include full configuration
467 information as output by the myconfig program in the perl source
468 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
469 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
470 can be used to help mail in a bug report.
472 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
473 don't tell anyone I said that.
477 The Perl motto is "There's more than one way to do it." Divining
478 how many more is left as an exercise to the reader.
480 The three principal virtues of a programmer are Laziness,
481 Impatience, and Hubris. See the Camel Book for why.