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 perlfilter Perl source filters
125 perldtrace Perl's support for DTrace
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 interpreter 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 perl5151delta Perl changes in version 5.15.1
166 perl5150delta Perl changes in version 5.15.0
167 perl5141delta Perl changes in version 5.14.1
168 perl5140delta Perl changes in version 5.14.0
169 perl51311delta Perl changes in version 5.13.11
170 perl51310delta Perl changes in version 5.13.10
171 perl5139delta Perl changes in version 5.13.9
172 perl5138delta Perl changes in version 5.13.8
173 perl5137delta Perl changes in version 5.13.7
174 perl5136delta Perl changes in version 5.13.6
175 perl5135delta Perl changes in version 5.13.5
176 perl5134delta Perl changes in version 5.13.4
177 perl5133delta Perl changes in version 5.13.3
178 perl5132delta Perl changes in version 5.13.2
179 perl5131delta Perl changes in version 5.13.1
180 perl5130delta Perl changes in version 5.13.0
181 perl5124delta Perl changes in version 5.12.4
182 perl5123delta Perl changes in version 5.12.3
183 perl5122delta Perl changes in version 5.12.2
184 perl5121delta Perl changes in version 5.12.1
185 perl5120delta Perl changes in version 5.12.0
186 perl5115delta Perl changes in version 5.11.5
187 perl5114delta Perl changes in version 5.11.4
188 perl5113delta Perl changes in version 5.11.3
189 perl5112delta Perl changes in version 5.11.2
190 perl5111delta Perl changes in version 5.11.1
191 perl5110delta Perl changes in version 5.11.0
192 perl5101delta Perl changes in version 5.10.1
193 perl5100delta Perl changes in version 5.10.0
194 perl595delta Perl changes in version 5.9.5
195 perl594delta Perl changes in version 5.9.4
196 perl593delta Perl changes in version 5.9.3
197 perl592delta Perl changes in version 5.9.2
198 perl591delta Perl changes in version 5.9.1
199 perl590delta Perl changes in version 5.9.0
200 perl589delta Perl changes in version 5.8.9
201 perl588delta Perl changes in version 5.8.8
202 perl587delta Perl changes in version 5.8.7
203 perl586delta Perl changes in version 5.8.6
204 perl585delta Perl changes in version 5.8.5
205 perl584delta Perl changes in version 5.8.4
206 perl583delta Perl changes in version 5.8.3
207 perl582delta Perl changes in version 5.8.2
208 perl581delta Perl changes in version 5.8.1
209 perl58delta Perl changes in version 5.8.0
210 perl573delta Perl changes in version 5.7.3
211 perl572delta Perl changes in version 5.7.2
212 perl571delta Perl changes in version 5.7.1
213 perl570delta Perl changes in version 5.7.0
214 perl561delta Perl changes in version 5.6.1
215 perl56delta Perl changes in version 5.6
216 perl5005delta Perl changes in version 5.005
217 perl5004delta Perl changes in version 5.004
219 perlexperiment A listing of experimental features in Perl
221 perlartistic Perl Artistic License
222 perlgpl GNU General Public License
224 =head2 Language-Specific
226 perlcn Perl for Simplified Chinese (in EUC-CN)
227 perljp Perl for Japanese (in EUC-JP)
228 perlko Perl for Korean (in EUC-KR)
229 perltw Perl for Traditional Chinese (in Big5)
231 =head2 Platform-Specific
233 perlaix Perl notes for AIX
234 perlamiga Perl notes for AmigaOS
235 perlbeos Perl notes for BeOS
236 perlbs2000 Perl notes for POSIX-BC BS2000
237 perlce Perl notes for WinCE
238 perlcygwin Perl notes for Cygwin
239 perldgux Perl notes for DG/UX
240 perldos Perl notes for DOS
241 perlepoc Perl notes for EPOC
242 perlfreebsd Perl notes for FreeBSD
243 perlhaiku Perl notes for Haiku
244 perlhpux Perl notes for HP-UX
245 perlhurd Perl notes for Hurd
246 perlirix Perl notes for Irix
247 perllinux Perl notes for Linux
248 perlmacos Perl notes for Mac OS (Classic)
249 perlmacosx Perl notes for Mac OS X
250 perlmpeix Perl notes for MPE/iX
251 perlnetware Perl notes for NetWare
252 perlopenbsd Perl notes for OpenBSD
253 perlos2 Perl notes for OS/2
254 perlos390 Perl notes for OS/390
255 perlos400 Perl notes for OS/400
256 perlplan9 Perl notes for Plan 9
257 perlqnx Perl notes for QNX
258 perlriscos Perl notes for RISC OS
259 perlsolaris Perl notes for Solaris
260 perlsymbian Perl notes for Symbian
261 perltru64 Perl notes for Tru64
262 perluts Perl notes for UTS
263 perlvmesa Perl notes for VM/ESA
264 perlvms Perl notes for VMS
265 perlvos Perl notes for Stratus VOS
266 perlwin32 Perl notes for Windows
269 On a Unix-like system, these documentation files will usually also be
270 available as manpages for use with the F<man> program.
272 In general, if something strange has gone wrong with your program and you're
273 not sure where you should look for help, try the B<-w> switch first. It will
274 often point out exactly where the trouble is.
278 Perl officially stands for Practical Extraction and Report Language,
279 except when it doesn't.
281 Perl was originally a language optimized for scanning arbitrary
282 text files, extracting information from those text files, and printing
283 reports based on that information. It quickly became a good language
284 for many system management tasks. Over the years, Perl has grown into
285 a general-purpose programming language. It's widely used for everything
286 from quick "one-liners" to full-scale application development.
288 The language is intended to be practical (easy to use, efficient,
289 complete) rather than beautiful (tiny, elegant, minimal).
291 Perl combines (in the author's opinion, anyway) some of the best
292 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
293 those languages should have little difficulty with it. (Language
294 historians will also note some vestiges of B<csh>, Pascal, and even
295 BASIC-PLUS.) Expression syntax corresponds closely to C
296 expression syntax. Unlike most Unix utilities, Perl does not
297 arbitrarily limit the size of your data--if you've got the memory,
298 Perl can slurp in your whole file as a single string. Recursion is of
299 unlimited depth. And the tables used by hashes (sometimes called
300 "associative arrays") grow as necessary to prevent degraded
301 performance. Perl can use sophisticated pattern matching techniques to
302 scan large amounts of data quickly. Although optimized for
303 scanning text, Perl also has many excellent tools for slicing
304 and dicing binary data.
306 But wait, there's more...
308 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
309 rewrite that provides the following additional benefits:
315 modularity and reusability using innumerable modules
317 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
321 embeddable and extensible
323 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
324 L<perlguts>, and L<xsubpp>.
328 roll-your-own magic variables (including multiple simultaneous DBM
331 Described in L<perltie> and L<AnyDBM_File>.
335 subroutines can now be overridden, autoloaded, and prototyped
337 Described in L<perlsub>.
341 arbitrarily nested data structures and anonymous functions
343 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
347 object-oriented programming
349 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
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.