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|typemap)? dist/ExtUtils-ParseXS/lib/
43 path perldoc cpan/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 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 perlxstypemap Perl XS C/Perl type conversion tools
151 perlclib Internal replacements for standard C library functions
152 perlguts Perl internal functions for those doing extensions
153 perlcall Perl calling conventions from C
154 perlmroapi Perl method resolution plugin interface
155 perlreapi Perl regular expression plugin interface
156 perlreguts Perl regular expression engine internals
158 perlapi Perl API listing (autogenerated)
159 perlintern Perl internal functions (autogenerated)
160 perliol C API for Perl's implementation of IO in Layers
161 perlapio Perl internal IO abstraction interface
163 perlhack Perl hackers guide
164 perlsource Guide to the Perl source tree
165 perlinterp Overview of the Perl interpreter source and how it works
166 perlhacktut Walk through the creation of a simple C code patch
167 perlhacktips Tips for Perl core C code hacking
168 perlpolicy Perl development policies
169 perlgit Using git with the Perl repository
173 perlbook Perl book information
174 perlcommunity Perl community information
176 perldoc Look up Perl documentation in Pod format
178 perlhist Perl history records
179 perldelta Perl changes since previous version
180 perl5170delta Perl changes in version 5.17.0
181 perl5160delta Perl changes in version 5.16.0
182 perl5142delta Perl changes in version 5.14.2
183 perl5141delta Perl changes in version 5.14.1
184 perl5140delta Perl changes in version 5.14.0
185 perl5124delta Perl changes in version 5.12.4
186 perl5123delta Perl changes in version 5.12.3
187 perl5122delta Perl changes in version 5.12.2
188 perl5121delta Perl changes in version 5.12.1
189 perl5120delta Perl changes in version 5.12.0
190 perl5101delta Perl changes in version 5.10.1
191 perl5100delta Perl changes in version 5.10.0
192 perl589delta Perl changes in version 5.8.9
193 perl588delta Perl changes in version 5.8.8
194 perl587delta Perl changes in version 5.8.7
195 perl586delta Perl changes in version 5.8.6
196 perl585delta Perl changes in version 5.8.5
197 perl584delta Perl changes in version 5.8.4
198 perl583delta Perl changes in version 5.8.3
199 perl582delta Perl changes in version 5.8.2
200 perl581delta Perl changes in version 5.8.1
201 perl58delta Perl changes in version 5.8.0
202 perl561delta Perl changes in version 5.6.1
203 perl56delta Perl changes in version 5.6
204 perl5005delta Perl changes in version 5.005
205 perl5004delta Perl changes in version 5.004
207 perlexperiment A listing of experimental features in Perl
209 perlartistic Perl Artistic License
210 perlgpl GNU General Public License
212 =head2 Language-Specific
214 =for buildtoc flag +r
216 perlcn Perl for Simplified Chinese (in EUC-CN)
217 perljp Perl for Japanese (in EUC-JP)
218 perlko Perl for Korean (in EUC-KR)
219 perltw Perl for Traditional Chinese (in Big5)
221 =head2 Platform-Specific
223 perlaix Perl notes for AIX
224 perlamiga Perl notes for AmigaOS
225 perlbeos Perl notes for BeOS
226 perlbs2000 Perl notes for POSIX-BC BS2000
227 perlce Perl notes for WinCE
228 perlcygwin Perl notes for Cygwin
229 perldgux Perl notes for DG/UX
230 perldos Perl notes for DOS
231 perlepoc Perl notes for EPOC
232 perlfreebsd Perl notes for FreeBSD
233 perlhaiku Perl notes for Haiku
234 perlhpux Perl notes for HP-UX
235 perlhurd Perl notes for Hurd
236 perlirix Perl notes for Irix
237 perllinux Perl notes for Linux
238 perlmacos Perl notes for Mac OS (Classic)
239 perlmacosx Perl notes for Mac OS X
240 perlmpeix Perl notes for MPE/iX
241 perlnetware Perl notes for NetWare
242 perlopenbsd Perl notes for OpenBSD
243 perlos2 Perl notes for OS/2
244 perlos390 Perl notes for OS/390
245 perlos400 Perl notes for OS/400
246 perlplan9 Perl notes for Plan 9
247 perlqnx Perl notes for QNX
248 perlriscos Perl notes for RISC OS
249 perlsolaris Perl notes for Solaris
250 perlsymbian Perl notes for Symbian
251 perltru64 Perl notes for Tru64
252 perluts Perl notes for UTS
253 perlvmesa Perl notes for VM/ESA
254 perlvms Perl notes for VMS
255 perlvos Perl notes for Stratus VOS
256 perlwin32 Perl notes for Windows
258 =for buildtoc flag -r
260 =head2 Stubs for Deleted Documents
268 =for buildtoc __END__
270 On a Unix-like system, these documentation files will usually also be
271 available as manpages for use with the F<man> program.
273 In general, if something strange has gone wrong with your program and you're
274 not sure where you should look for help, try the B<-w> switch first. It will
275 often point out exactly where the trouble is.
279 Perl officially stands for Practical Extraction and Report Language,
280 except when it doesn't.
282 Perl was originally a language optimized for scanning arbitrary
283 text files, extracting information from those text files, and printing
284 reports based on that information. It quickly became a good language
285 for many system management tasks. Over the years, Perl has grown into
286 a general-purpose programming language. It's widely used for everything
287 from quick "one-liners" to full-scale application development.
289 The language is intended to be practical (easy to use, efficient,
290 complete) rather than beautiful (tiny, elegant, minimal).
292 Perl combines (in the author's opinion, anyway) some of the best
293 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
294 those languages should have little difficulty with it. (Language
295 historians will also note some vestiges of B<csh>, Pascal, and even
296 BASIC-PLUS.) Expression syntax corresponds closely to C
297 expression syntax. Unlike most Unix utilities, Perl does not
298 arbitrarily limit the size of your data--if you've got the memory,
299 Perl can slurp in your whole file as a single string. Recursion is of
300 unlimited depth. And the tables used by hashes (sometimes called
301 "associative arrays") grow as necessary to prevent degraded
302 performance. Perl can use sophisticated pattern matching techniques to
303 scan large amounts of data quickly. Although optimized for
304 scanning text, Perl also has many excellent tools for slicing
305 and dicing binary data.
307 But wait, there's more...
309 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
310 rewrite that provides the following additional benefits:
316 modularity and reusability using innumerable modules
318 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
322 embeddable and extensible
324 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlxstypemap>,
325 L<perlcall>, L<perlguts>, and L<xsubpp>.
329 roll-your-own magic variables (including multiple simultaneous DBM
332 Described in L<perltie> and L<AnyDBM_File>.
336 subroutines can now be overridden, autoloaded, and prototyped
338 Described in L<perlsub>.
342 arbitrarily nested data structures and anonymous functions
344 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
348 object-oriented programming
350 Described in L<perlobj> and L<perlootut>.
354 support for light-weight processes (threads)
356 Described in L<perlthrtut> and L<threads>.
360 support for Unicode, internationalization, and localization
362 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
368 Described in L<perlsub>.
372 regular expression enhancements
374 Described in L<perlre>, with additional examples in L<perlop>.
378 enhanced debugger and interactive Perl environment,
379 with integrated editor support
381 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
385 POSIX 1003.1 compliant library
387 Described in L<POSIX>.
391 Okay, that's I<definitely> enough hype.
395 Perl is available for most operating systems, including virtually
396 all Unix-like platforms. See L<perlport/"Supported Platforms">
405 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
407 If your Perl success stories and testimonials may be of help to others
408 who wish to advocate the use of Perl in their applications,
409 or if you wish to simply express your gratitude to Larry and the
410 Perl developers, please write to perl-thanks@perl.org .
414 "@INC" locations of perl libraries
418 http://www.perl.org/ the Perl homepage
419 http://www.perl.com/ Perl articles (O'Reilly)
420 http://www.cpan.org/ the Comprehensive Perl Archive
421 http://www.pm.org/ the Perl Mongers
425 The C<use warnings> pragma (and the B<-w> switch) produces some
428 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
429 diagnostics> pragma automatically turns Perl's normally terse warnings
430 and errors into these longer forms.
432 Compilation errors will tell you the line number of the error, with an
433 indication of the next token or token type that was to be examined.
434 (In a script passed to Perl via B<-e> switches, each
435 B<-e> is counted as one line.)
437 Setuid scripts have additional constraints that can produce error
438 messages such as "Insecure dependency". See L<perlsec>.
440 Did we mention that you should definitely consider using the B<-w>
445 The B<-w> switch is not mandatory.
447 Perl is at the mercy of your machine's definitions of various
448 operations such as type casting, atof(), and floating-point
449 output with sprintf().
451 If your stdio requires a seek or eof between reads and writes on a
452 particular stream, so does Perl. (This doesn't apply to sysread()
455 While none of the built-in data types have any arbitrary size limits
456 (apart from memory size), there are still a few arbitrary limits: a
457 given variable name may not be longer than 251 characters. Line numbers
458 displayed by diagnostics are internally stored as short integers,
459 so they are limited to a maximum of 65535 (higher numbers usually being
460 affected by wraparound).
462 You may mail your bug reports (be sure to include full configuration
463 information as output by the myconfig program in the perl source
464 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
465 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
466 can be used to help mail in a bug report.
468 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
469 don't tell anyone I said that.
473 The Perl motto is "There's more than one way to do it." Divining
474 how many more is left as an exercise to the reader.
476 The three principal virtues of a programmer are Laziness,
477 Impatience, and Hubris. See the Camel Book for why.