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 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 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 perl5161delta Perl changes in version 5.16.1
181 perl5160delta Perl changes in version 5.16.0
182 perl5160delta Perl changes in version 5.16.0
183 perl5143delta Perl changes in version 5.14.3
184 perl5142delta Perl changes in version 5.14.2
185 perl5141delta Perl changes in version 5.14.1
186 perl5140delta Perl changes in version 5.14.0
187 perl5124delta Perl changes in version 5.12.4
188 perl5123delta Perl changes in version 5.12.3
189 perl5122delta Perl changes in version 5.12.2
190 perl5121delta Perl changes in version 5.12.1
191 perl5120delta Perl changes in version 5.12.0
192 perl5101delta Perl changes in version 5.10.1
193 perl5100delta Perl changes in version 5.10.0
194 perl589delta Perl changes in version 5.8.9
195 perl588delta Perl changes in version 5.8.8
196 perl587delta Perl changes in version 5.8.7
197 perl586delta Perl changes in version 5.8.6
198 perl585delta Perl changes in version 5.8.5
199 perl584delta Perl changes in version 5.8.4
200 perl583delta Perl changes in version 5.8.3
201 perl582delta Perl changes in version 5.8.2
202 perl581delta Perl changes in version 5.8.1
203 perl58delta Perl changes in version 5.8.0
204 perl561delta Perl changes in version 5.6.1
205 perl56delta Perl changes in version 5.6
206 perl5005delta Perl changes in version 5.005
207 perl5004delta Perl changes in version 5.004
209 perlexperiment A listing of experimental features in Perl
211 perlartistic Perl Artistic License
212 perlgpl GNU General Public License
214 =head2 Language-Specific
216 =for buildtoc flag +r
218 perlcn Perl for Simplified Chinese (in EUC-CN)
219 perljp Perl for Japanese (in EUC-JP)
220 perlko Perl for Korean (in EUC-KR)
221 perltw Perl for Traditional Chinese (in Big5)
223 =head2 Platform-Specific
225 perlaix Perl notes for AIX
226 perlamiga Perl notes for AmigaOS
227 perlbeos Perl notes for BeOS
228 perlbs2000 Perl notes for POSIX-BC BS2000
229 perlce Perl notes for WinCE
230 perlcygwin Perl notes for Cygwin
231 perldgux Perl notes for DG/UX
232 perldos Perl notes for DOS
233 perlepoc Perl notes for EPOC
234 perlfreebsd Perl notes for FreeBSD
235 perlhaiku Perl notes for Haiku
236 perlhpux Perl notes for HP-UX
237 perlhurd Perl notes for Hurd
238 perlirix Perl notes for Irix
239 perllinux Perl notes for Linux
240 perlmacos Perl notes for Mac OS (Classic)
241 perlmacosx Perl notes for Mac OS X
242 perlmpeix Perl notes for MPE/iX
243 perlnetware Perl notes for NetWare
244 perlopenbsd Perl notes for OpenBSD
245 perlos2 Perl notes for OS/2
246 perlos390 Perl notes for OS/390
247 perlos400 Perl notes for OS/400
248 perlplan9 Perl notes for Plan 9
249 perlqnx Perl notes for QNX
250 perlriscos Perl notes for RISC OS
251 perlsolaris Perl notes for Solaris
252 perlsymbian Perl notes for Symbian
253 perltru64 Perl notes for Tru64
254 perluts Perl notes for UTS
255 perlvmesa Perl notes for VM/ESA
256 perlvms Perl notes for VMS
257 perlvos Perl notes for Stratus VOS
258 perlwin32 Perl notes for Windows
260 =for buildtoc flag -r
262 =head2 Stubs for Deleted Documents
270 =for buildtoc __END__
272 On a Unix-like system, these documentation files will usually also be
273 available as manpages for use with the F<man> program.
275 In general, if something strange has gone wrong with your program and you're
276 not sure where you should look for help, try the B<-w> switch first. It will
277 often point out exactly where the trouble is.
281 Perl officially stands for Practical Extraction and Report Language,
282 except when it doesn't.
284 Perl was originally a language optimized for scanning arbitrary
285 text files, extracting information from those text files, and printing
286 reports based on that information. It quickly became a good language
287 for many system management tasks. Over the years, Perl has grown into
288 a general-purpose programming language. It's widely used for everything
289 from quick "one-liners" to full-scale application development.
291 The language is intended to be practical (easy to use, efficient,
292 complete) rather than beautiful (tiny, elegant, minimal).
294 Perl combines (in the author's opinion, anyway) some of the best
295 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
296 those languages should have little difficulty with it. (Language
297 historians will also note some vestiges of B<csh>, Pascal, and even
298 BASIC-PLUS.) Expression syntax corresponds closely to C
299 expression syntax. Unlike most Unix utilities, Perl does not
300 arbitrarily limit the size of your data--if you've got the memory,
301 Perl can slurp in your whole file as a single string. Recursion is of
302 unlimited depth. And the tables used by hashes (sometimes called
303 "associative arrays") grow as necessary to prevent degraded
304 performance. Perl can use sophisticated pattern matching techniques to
305 scan large amounts of data quickly. Although optimized for
306 scanning text, Perl also has many excellent tools for slicing
307 and dicing binary data.
309 But wait, there's more...
311 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
312 rewrite that provides the following additional benefits:
318 modularity and reusability using innumerable modules
320 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
324 embeddable and extensible
326 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlxstypemap>,
327 L<perlcall>, L<perlguts>, and L<xsubpp>.
331 roll-your-own magic variables (including multiple simultaneous DBM
334 Described in L<perltie> and L<AnyDBM_File>.
338 subroutines can now be overridden, autoloaded, and prototyped
340 Described in L<perlsub>.
344 arbitrarily nested data structures and anonymous functions
346 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
350 object-oriented programming
352 Described in L<perlobj> and L<perlootut>.
356 support for light-weight processes (threads)
358 Described in L<perlthrtut> and L<threads>.
362 support for Unicode, internationalization, and localization
364 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
370 Described in L<perlsub>.
374 regular expression enhancements
376 Described in L<perlre>, with additional examples in L<perlop>.
380 enhanced debugger and interactive Perl environment,
381 with integrated editor support
383 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
387 POSIX 1003.1 compliant library
389 Described in L<POSIX>.
393 Okay, that's I<definitely> enough hype.
397 Perl is available for most operating systems, including virtually
398 all Unix-like platforms. See L<perlport/"Supported Platforms">
407 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
409 If your Perl success stories and testimonials may be of help to others
410 who wish to advocate the use of Perl in their applications,
411 or if you wish to simply express your gratitude to Larry and the
412 Perl developers, please write to perl-thanks@perl.org .
416 "@INC" locations of perl libraries
420 http://www.perl.org/ the Perl homepage
421 http://www.perl.com/ Perl articles (O'Reilly)
422 http://www.cpan.org/ the Comprehensive Perl Archive
423 http://www.pm.org/ the Perl Mongers
427 The C<use warnings> pragma (and the B<-w> switch) produces some
430 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
431 diagnostics> pragma automatically turns Perl's normally terse warnings
432 and errors into these longer forms.
434 Compilation errors will tell you the line number of the error, with an
435 indication of the next token or token type that was to be examined.
436 (In a script passed to Perl via B<-e> switches, each
437 B<-e> is counted as one line.)
439 Setuid scripts have additional constraints that can produce error
440 messages such as "Insecure dependency". See L<perlsec>.
442 Did we mention that you should definitely consider using the B<-w>
447 The B<-w> switch is not mandatory.
449 Perl is at the mercy of your machine's definitions of various
450 operations such as type casting, atof(), and floating-point
451 output with sprintf().
453 If your stdio requires a seek or eof between reads and writes on a
454 particular stream, so does Perl. (This doesn't apply to sysread()
457 While none of the built-in data types have any arbitrary size limits
458 (apart from memory size), there are still a few arbitrary limits: a
459 given variable name may not be longer than 251 characters. Line numbers
460 displayed by diagnostics are internally stored as short integers,
461 so they are limited to a maximum of 65535 (higher numbers usually being
462 affected by wraparound).
464 You may mail your bug reports (be sure to include full configuration
465 information as output by the myconfig program in the perl source
466 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
467 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
468 can be used to help mail in a bug report.
470 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
471 don't tell anyone I said that.
475 The Perl motto is "There's more than one way to do it." Divining
476 how many more is left as an exercise to the reader.
478 The three principal virtues of a programmer are Laziness,
479 Impatience, and Hubris. See the Camel Book for why.