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 perl51311delta Perl changes in version 5.13.11
166 perl51310delta Perl changes in version 5.13.10
167 perl5139delta Perl changes in version 5.13.9
168 perl5138delta Perl changes in version 5.13.8
169 perl5137delta Perl changes in version 5.13.7
170 perl5136delta Perl changes in version 5.13.6
171 perl5135delta Perl changes in version 5.13.5
172 perl5134delta Perl changes in version 5.13.4
173 perl5133delta Perl changes in version 5.13.3
174 perl5132delta Perl changes in version 5.13.2
175 perl5131delta Perl changes in version 5.13.1
176 perl5130delta Perl changes in version 5.13.0
177 perl5123delta Perl changes in version 5.12.3
178 perl5122delta Perl changes in version 5.12.2
179 perl5121delta Perl changes in version 5.12.1
180 perl5120delta Perl changes in version 5.12.0
181 perl5115delta Perl changes in version 5.11.5
182 perl5114delta Perl changes in version 5.11.4
183 perl5113delta Perl changes in version 5.11.3
184 perl5112delta Perl changes in version 5.11.2
185 perl5111delta Perl changes in version 5.11.1
186 perl5110delta Perl changes in version 5.11.0
187 perl5101delta Perl changes in version 5.10.1
188 perl5100delta Perl changes in version 5.10.0
189 perl595delta Perl changes in version 5.9.5
190 perl594delta Perl changes in version 5.9.4
191 perl593delta Perl changes in version 5.9.3
192 perl592delta Perl changes in version 5.9.2
193 perl591delta Perl changes in version 5.9.1
194 perl590delta Perl changes in version 5.9.0
195 perl589delta Perl changes in version 5.8.9
196 perl588delta Perl changes in version 5.8.8
197 perl587delta Perl changes in version 5.8.7
198 perl586delta Perl changes in version 5.8.6
199 perl585delta Perl changes in version 5.8.5
200 perl584delta Perl changes in version 5.8.4
201 perl583delta Perl changes in version 5.8.3
202 perl582delta Perl changes in version 5.8.2
203 perl581delta Perl changes in version 5.8.1
204 perl58delta Perl changes in version 5.8.0
205 perl573delta Perl changes in version 5.7.3
206 perl572delta Perl changes in version 5.7.2
207 perl571delta Perl changes in version 5.7.1
208 perl570delta Perl changes in version 5.7.0
209 perl561delta Perl changes in version 5.6.1
210 perl56delta Perl changes in version 5.6
211 perl5005delta Perl changes in version 5.005
212 perl5004delta Perl changes in version 5.004
214 perlartistic Perl Artistic License
215 perlgpl GNU General Public License
217 =head2 Language-Specific
219 perlcn Perl for Simplified Chinese (in EUC-CN)
220 perljp Perl for Japanese (in EUC-JP)
221 perlko Perl for Korean (in EUC-KR)
222 perltw Perl for Traditional Chinese (in Big5)
224 =head2 Platform-Specific
226 perlaix Perl notes for AIX
227 perlamiga Perl notes for AmigaOS
228 perlbeos Perl notes for BeOS
229 perlbs2000 Perl notes for POSIX-BC BS2000
230 perlce Perl notes for WinCE
231 perlcygwin Perl notes for Cygwin
232 perldgux Perl notes for DG/UX
233 perldos Perl notes for DOS
234 perlepoc Perl notes for EPOC
235 perlfreebsd Perl notes for FreeBSD
236 perlhaiku Perl notes for Haiku
237 perlhpux Perl notes for HP-UX
238 perlhurd Perl notes for Hurd
239 perlirix Perl notes for Irix
240 perllinux Perl notes for Linux
241 perlmacos Perl notes for Mac OS (Classic)
242 perlmacosx Perl notes for Mac OS X
243 perlmpeix Perl notes for MPE/iX
244 perlnetware Perl notes for NetWare
245 perlopenbsd Perl notes for OpenBSD
246 perlos2 Perl notes for OS/2
247 perlos390 Perl notes for OS/390
248 perlos400 Perl notes for OS/400
249 perlplan9 Perl notes for Plan 9
250 perlqnx Perl notes for QNX
251 perlriscos Perl notes for RISC OS
252 perlsolaris Perl notes for Solaris
253 perlsymbian Perl notes for Symbian
254 perltru64 Perl notes for Tru64
255 perluts Perl notes for UTS
256 perlvmesa Perl notes for VM/ESA
257 perlvms Perl notes for VMS
258 perlvos Perl notes for Stratus VOS
259 perlwin32 Perl notes for Windows
262 On a Unix-like system, these documentation files will usually also be
263 available as manpages for use with the F<man> program.
265 In general, if something strange has gone wrong with your program and you're
266 not sure where you should look for help, try the B<-w> switch first. It will
267 often point out exactly where the trouble is.
271 Perl officially stands for Practical Extraction and Report Language,
272 except when it doesn't.
274 Perl was originally a language optimized for scanning arbitrary
275 text files, extracting information from those text files, and printing
276 reports based on that information. It quickly became a good language
277 for many system management tasks. Over the years, Perl has grown into
278 a general-purpose programming language. It's widely used for everything
279 from quick "one-liners" to full-scale application development.
281 The language is intended to be practical (easy to use, efficient,
282 complete) rather than beautiful (tiny, elegant, minimal).
284 Perl combines (in the author's opinion, anyway) some of the best
285 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
286 those languages should have little difficulty with it. (Language
287 historians will also note some vestiges of B<csh>, Pascal, and even
288 BASIC-PLUS.) Expression syntax corresponds closely to C
289 expression syntax. Unlike most Unix utilities, Perl does not
290 arbitrarily limit the size of your data--if you've got the memory,
291 Perl can slurp in your whole file as a single string. Recursion is of
292 unlimited depth. And the tables used by hashes (sometimes called
293 "associative arrays") grow as necessary to prevent degraded
294 performance. Perl can use sophisticated pattern matching techniques to
295 scan large amounts of data quickly. Although optimized for
296 scanning text, Perl also has many excellent tools for slicing
297 and dicing binary data.
299 But wait, there's more...
301 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
302 rewrite that provides the following additional benefits:
308 modularity and reusability using innumerable modules
310 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
314 embeddable and extensible
316 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
317 L<perlguts>, and L<xsubpp>.
321 roll-your-own magic variables (including multiple simultaneous DBM
324 Described in L<perltie> and L<AnyDBM_File>.
328 subroutines can now be overridden, autoloaded, and prototyped
330 Described in L<perlsub>.
334 arbitrarily nested data structures and anonymous functions
336 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
340 object-oriented programming
342 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
347 support for light-weight processes (threads)
349 Described in L<perlthrtut> and L<threads>.
353 support for Unicode, internationalization, and localization
355 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
361 Described in L<perlsub>.
365 regular expression enhancements
367 Described in L<perlre>, with additional examples in L<perlop>.
371 enhanced debugger and interactive Perl environment,
372 with integrated editor support
374 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
378 POSIX 1003.1 compliant library
380 Described in L<POSIX>.
384 Okay, that's I<definitely> enough hype.
388 Perl is available for most operating systems, including virtually
389 all Unix-like platforms. See L<perlport/"Supported Platforms">
398 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
400 If your Perl success stories and testimonials may be of help to others
401 who wish to advocate the use of Perl in their applications,
402 or if you wish to simply express your gratitude to Larry and the
403 Perl developers, please write to perl-thanks@perl.org .
407 "@INC" locations of perl libraries
411 http://www.perl.org/ the Perl homepage
412 http://www.perl.com/ Perl articles (O'Reilly)
413 http://www.cpan.org/ the Comprehensive Perl Archive
414 http://www.pm.org/ the Perl Mongers
418 The C<use warnings> pragma (and the B<-w> switch) produces some
421 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
422 diagnostics> pragma automatically turns Perl's normally terse warnings
423 and errors into these longer forms.
425 Compilation errors will tell you the line number of the error, with an
426 indication of the next token or token type that was to be examined.
427 (In a script passed to Perl via B<-e> switches, each
428 B<-e> is counted as one line.)
430 Setuid scripts have additional constraints that can produce error
431 messages such as "Insecure dependency". See L<perlsec>.
433 Did we mention that you should definitely consider using the B<-w>
438 The B<-w> switch is not mandatory.
440 Perl is at the mercy of your machine's definitions of various
441 operations such as type casting, atof(), and floating-point
442 output with sprintf().
444 If your stdio requires a seek or eof between reads and writes on a
445 particular stream, so does Perl. (This doesn't apply to sysread()
448 While none of the built-in data types have any arbitrary size limits
449 (apart from memory size), there are still a few arbitrary limits: a
450 given variable name may not be longer than 251 characters. Line numbers
451 displayed by diagnostics are internally stored as short integers,
452 so they are limited to a maximum of 65535 (higher numbers usually being
453 affected by wraparound).
455 You may mail your bug reports (be sure to include full configuration
456 information as output by the myconfig program in the perl source
457 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
458 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
459 can be used to help mail in a bug report.
461 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
462 don't tell anyone I said that.
466 The Perl motto is "There's more than one way to do it." Divining
467 how many more is left as an exercise to the reader.
469 The three principal virtues of a programmer are Laziness,
470 Impatience, and Hubris. See the Camel Book for why.