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 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 6.0.0 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 perlsource Guide to the Perl source tree
149 perlinterp Overview of the Perl intepreter source and how it works
150 perlhacktut Walk through the creation of a simple C code patch
151 perlhacktips Tips for Perl core C code hacking
152 perlpolicy Perl development policies
153 perlgit Using git with the Perl repository
157 perlbook Perl book information
158 perlcommunity Perl community information
159 perltodo Perl things to do
161 perldoc Look up Perl documentation in Pod format
163 perlhist Perl history records
164 perldelta Perl changes since previous version
165 perl5139delta Perl changes in version 5.13.9
166 perl5138delta Perl changes in version 5.13.8
167 perl5137delta Perl changes in version 5.13.7
168 perl5136delta Perl changes in version 5.13.6
169 perl5135delta Perl changes in version 5.13.5
170 perl5134delta Perl changes in version 5.13.4
171 perl5133delta Perl changes in version 5.13.3
172 perl5132delta Perl changes in version 5.13.2
173 perl5131delta Perl changes in version 5.13.1
174 perl5130delta Perl changes in version 5.13.0
175 perl5123delta Perl changes in version 5.12.3
176 perl5122delta Perl changes in version 5.12.2
177 perl5121delta Perl changes in version 5.12.1
178 perl5120delta Perl changes in version 5.12.0
179 perl5115delta Perl changes in version 5.11.5
180 perl5114delta Perl changes in version 5.11.4
181 perl5113delta Perl changes in version 5.11.3
182 perl5112delta Perl changes in version 5.11.2
183 perl5111delta Perl changes in version 5.11.1
184 perl5110delta Perl changes in version 5.11.0
185 perl5101delta Perl changes in version 5.10.1
186 perl5100delta Perl changes in version 5.10.0
187 perl595delta Perl changes in version 5.9.5
188 perl594delta Perl changes in version 5.9.4
189 perl593delta Perl changes in version 5.9.3
190 perl592delta Perl changes in version 5.9.2
191 perl591delta Perl changes in version 5.9.1
192 perl590delta Perl changes in version 5.9.0
193 perl589delta Perl changes in version 5.8.9
194 perl588delta Perl changes in version 5.8.8
195 perl587delta Perl changes in version 5.8.7
196 perl586delta Perl changes in version 5.8.6
197 perl585delta Perl changes in version 5.8.5
198 perl584delta Perl changes in version 5.8.4
199 perl583delta Perl changes in version 5.8.3
200 perl582delta Perl changes in version 5.8.2
201 perl581delta Perl changes in version 5.8.1
202 perl58delta Perl changes in version 5.8.0
203 perl573delta Perl changes in version 5.7.3
204 perl572delta Perl changes in version 5.7.2
205 perl571delta Perl changes in version 5.7.1
206 perl570delta Perl changes in version 5.7.0
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 perlartistic Perl Artistic License
213 perlgpl GNU General Public License
215 =head2 Language-Specific
217 perlcn Perl for Simplified Chinese (in EUC-CN)
218 perljp Perl for Japanese (in EUC-JP)
219 perlko Perl for Korean (in EUC-KR)
220 perltw Perl for Traditional Chinese (in Big5)
222 =head2 Platform-Specific
224 perlaix Perl notes for AIX
225 perlamiga Perl notes for AmigaOS
226 perlbeos Perl notes for BeOS
227 perlbs2000 Perl notes for POSIX-BC BS2000
228 perlce Perl notes for WinCE
229 perlcygwin Perl notes for Cygwin
230 perldgux Perl notes for DG/UX
231 perldos Perl notes for DOS
232 perlepoc Perl notes for EPOC
233 perlfreebsd Perl notes for FreeBSD
234 perlhaiku Perl notes for Haiku
235 perlhpux Perl notes for HP-UX
236 perlhurd Perl notes for Hurd
237 perlirix Perl notes for Irix
238 perllinux Perl notes for Linux
239 perlmacos Perl notes for Mac OS (Classic)
240 perlmacosx Perl notes for Mac OS X
241 perlmpeix Perl notes for MPE/iX
242 perlnetware Perl notes for NetWare
243 perlopenbsd Perl notes for OpenBSD
244 perlos2 Perl notes for OS/2
245 perlos390 Perl notes for OS/390
246 perlos400 Perl notes for OS/400
247 perlplan9 Perl notes for Plan 9
248 perlqnx Perl notes for QNX
249 perlriscos Perl notes for RISC OS
250 perlsolaris Perl notes for Solaris
251 perlsymbian Perl notes for Symbian
252 perltru64 Perl notes for Tru64
253 perluts Perl notes for UTS
254 perlvmesa Perl notes for VM/ESA
255 perlvms Perl notes for VMS
256 perlvos Perl notes for Stratus VOS
257 perlwin32 Perl notes for Windows
260 On a Unix-like system, these documentation files will usually also be
261 available as manpages for use with the F<man> program.
263 In general, if something strange has gone wrong with your program and you're
264 not sure where you should look for help, try the B<-w> switch first. It will
265 often point out exactly where the trouble is.
269 Perl officially stands for Practical Extraction and Report Language,
270 except when it doesn't.
272 Perl was originally a language optimized for scanning arbitrary
273 text files, extracting information from those text files, and printing
274 reports based on that information. It quickly became a good language
275 for many system management tasks. Over the years, Perl has grown into
276 a general-purpose progammming language. It's widely used for everything
277 from quick "one-liners" to full-scale application development.
279 The language is intended to be practical (easy to use, efficient,
280 complete) rather than beautiful (tiny, elegant, minimal).
282 Perl combines (in the author's opinion, anyway) some of the best
283 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
284 those languages should have little difficulty with it. (Language
285 historians will also note some vestiges of B<csh>, Pascal, and even
286 BASIC-PLUS.) Expression syntax corresponds closely to C
287 expression syntax. Unlike most Unix utilities, Perl does not
288 arbitrarily limit the size of your data--if you've got the memory,
289 Perl can slurp in your whole file as a single string. Recursion is of
290 unlimited depth. And the tables used by hashes (sometimes called
291 "associative arrays") grow as necessary to prevent degraded
292 performance. Perl can use sophisticated pattern matching techniques to
293 scan large amounts of data quickly. Although optimized for
294 scanning text, Perl also has many excellent tools for slicing
295 and dicing binary data.
297 But wait, there's more...
299 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
300 rewrite that provides the following additional benefits:
306 modularity and reusability using innumerable modules
308 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
312 embeddable and extensible
314 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
315 L<perlguts>, and L<xsubpp>.
319 roll-your-own magic variables (including multiple simultaneous DBM
322 Described in L<perltie> and L<AnyDBM_File>.
326 subroutines can now be overridden, autoloaded, and prototyped
328 Described in L<perlsub>.
332 arbitrarily nested data structures and anonymous functions
334 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
338 object-oriented programming
340 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
345 support for light-weight processes (threads)
347 Described in L<perlthrtut> and L<threads>.
351 support for Unicode, internationalization, and localization
353 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
359 Described in L<perlsub>.
363 regular expression enhancements
365 Described in L<perlre>, with additional examples in L<perlop>.
369 enhanced debugger and interactive Perl environment,
370 with integrated editor support
372 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
376 POSIX 1003.1 compliant library
378 Described in L<POSIX>.
382 Okay, that's I<definitely> enough hype.
386 Perl is available for most operating systems, including virtually
387 all Unix-like platforms. See L<perlport/"Supported Platforms">
396 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
398 If your Perl success stories and testimonials may be of help to others
399 who wish to advocate the use of Perl in their applications,
400 or if you wish to simply express your gratitude to Larry and the
401 Perl developers, please write to perl-thanks@perl.org .
405 "@INC" locations of perl libraries
409 http://www.perl.org/ the Perl homepage
410 http://www.perl.com/ Perl articles (O'Reilly)
411 http://www.cpan.org/ the Comprehensive Perl Archive
412 http://www.pm.org/ the Perl Mongers
416 The C<use warnings> pragma (and the B<-w> switch) produces some
419 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
420 diagnostics> pragma automatically turns Perl's normally terse warnings
421 and errors into these longer forms.
423 Compilation errors will tell you the line number of the error, with an
424 indication of the next token or token type that was to be examined.
425 (In a script passed to Perl via B<-e> switches, each
426 B<-e> is counted as one line.)
428 Setuid scripts have additional constraints that can produce error
429 messages such as "Insecure dependency". See L<perlsec>.
431 Did we mention that you should definitely consider using the B<-w>
436 The B<-w> switch is not mandatory.
438 Perl is at the mercy of your machine's definitions of various
439 operations such as type casting, atof(), and floating-point
440 output with sprintf().
442 If your stdio requires a seek or eof between reads and writes on a
443 particular stream, so does Perl. (This doesn't apply to sysread()
446 While none of the built-in data types have any arbitrary size limits
447 (apart from memory size), there are still a few arbitrary limits: a
448 given variable name may not be longer than 251 characters. Line numbers
449 displayed by diagnostics are internally stored as short integers,
450 so they are limited to a maximum of 65535 (higher numbers usually being
451 affected by wraparound).
453 You may mail your bug reports (be sure to include full configuration
454 information as output by the myconfig program in the perl source
455 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
456 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
457 can be used to help mail in a bug report.
459 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
460 don't tell anyone I said that.
464 The Perl motto is "There's more than one way to do it." Divining
465 how many more is left as an exercise to the reader.
467 The three principal virtues of a programmer are Laziness,
468 Impatience, and Hubris. See the Camel Book for why.