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 perldtrace Perl's support for DTrace
129 perlglossary Perl Glossary
131 =head2 Internals and C Language Interface
133 perlembed Perl ways to embed perl in your C or C++ application
134 perldebguts Perl debugging guts and tips
135 perlxstut Perl XS tutorial
136 perlxs Perl XS application programming interface
137 perlclib Internal replacements for standard C library functions
138 perlguts Perl internal functions for those doing extensions
139 perlcall Perl calling conventions from C
140 perlmroapi Perl method resolution plugin interface
141 perlreapi Perl regular expression plugin interface
142 perlreguts Perl regular expression engine internals
144 perlapi Perl API listing (autogenerated)
145 perlintern Perl internal functions (autogenerated)
146 perliol C API for Perl's implementation of IO in Layers
147 perlapio Perl internal IO abstraction interface
149 perlhack Perl hackers guide
150 perlsource Guide to the Perl source tree
151 perlinterp Overview of the Perl interpreter source and how it works
152 perlhacktut Walk through the creation of a simple C code patch
153 perlhacktips Tips for Perl core C code hacking
154 perlpolicy Perl development policies
155 perlgit Using git with the Perl repository
159 perlbook Perl book information
160 perlcommunity Perl community information
161 perltodo Perl things to do
163 perldoc Look up Perl documentation in Pod format
165 perlhist Perl history records
166 perldelta Perl changes since previous version
167 perl5150delta Perl changes in version 5.15.0
168 perl5141delta Perl changes in version 5.14.1
169 perl5140delta Perl changes in version 5.14.0
170 perl51311delta Perl changes in version 5.13.11
171 perl51310delta Perl changes in version 5.13.10
172 perl5139delta Perl changes in version 5.13.9
173 perl5138delta Perl changes in version 5.13.8
174 perl5137delta Perl changes in version 5.13.7
175 perl5136delta Perl changes in version 5.13.6
176 perl5135delta Perl changes in version 5.13.5
177 perl5134delta Perl changes in version 5.13.4
178 perl5133delta Perl changes in version 5.13.3
179 perl5132delta Perl changes in version 5.13.2
180 perl5131delta Perl changes in version 5.13.1
181 perl5130delta Perl changes in version 5.13.0
182 perl5124delta Perl changes in version 5.12.4
183 perl5123delta Perl changes in version 5.12.3
184 perl5122delta Perl changes in version 5.12.2
185 perl5121delta Perl changes in version 5.12.1
186 perl5120delta Perl changes in version 5.12.0
187 perl5115delta Perl changes in version 5.11.5
188 perl5114delta Perl changes in version 5.11.4
189 perl5113delta Perl changes in version 5.11.3
190 perl5112delta Perl changes in version 5.11.2
191 perl5111delta Perl changes in version 5.11.1
192 perl5110delta Perl changes in version 5.11.0
193 perl5101delta Perl changes in version 5.10.1
194 perl5100delta Perl changes in version 5.10.0
195 perl595delta Perl changes in version 5.9.5
196 perl594delta Perl changes in version 5.9.4
197 perl593delta Perl changes in version 5.9.3
198 perl592delta Perl changes in version 5.9.2
199 perl591delta Perl changes in version 5.9.1
200 perl590delta Perl changes in version 5.9.0
201 perl589delta Perl changes in version 5.8.9
202 perl588delta Perl changes in version 5.8.8
203 perl587delta Perl changes in version 5.8.7
204 perl586delta Perl changes in version 5.8.6
205 perl585delta Perl changes in version 5.8.5
206 perl584delta Perl changes in version 5.8.4
207 perl583delta Perl changes in version 5.8.3
208 perl582delta Perl changes in version 5.8.2
209 perl581delta Perl changes in version 5.8.1
210 perl58delta Perl changes in version 5.8.0
211 perl573delta Perl changes in version 5.7.3
212 perl572delta Perl changes in version 5.7.2
213 perl571delta Perl changes in version 5.7.1
214 perl570delta Perl changes in version 5.7.0
215 perl561delta Perl changes in version 5.6.1
216 perl56delta Perl changes in version 5.6
217 perl5005delta Perl changes in version 5.005
218 perl5004delta Perl changes in version 5.004
220 perlartistic Perl Artistic License
221 perlgpl GNU General Public License
223 =head2 Language-Specific
225 perlcn Perl for Simplified Chinese (in EUC-CN)
226 perljp Perl for Japanese (in EUC-JP)
227 perlko Perl for Korean (in EUC-KR)
228 perltw Perl for Traditional Chinese (in Big5)
230 =head2 Platform-Specific
232 perlaix Perl notes for AIX
233 perlamiga Perl notes for AmigaOS
234 perlbeos Perl notes for BeOS
235 perlbs2000 Perl notes for POSIX-BC BS2000
236 perlce Perl notes for WinCE
237 perlcygwin Perl notes for Cygwin
238 perldgux Perl notes for DG/UX
239 perldos Perl notes for DOS
240 perlepoc Perl notes for EPOC
241 perlfreebsd Perl notes for FreeBSD
242 perlhaiku Perl notes for Haiku
243 perlhpux Perl notes for HP-UX
244 perlhurd Perl notes for Hurd
245 perlirix Perl notes for Irix
246 perllinux Perl notes for Linux
247 perlmacos Perl notes for Mac OS (Classic)
248 perlmacosx Perl notes for Mac OS X
249 perlmpeix Perl notes for MPE/iX
250 perlnetware Perl notes for NetWare
251 perlopenbsd Perl notes for OpenBSD
252 perlos2 Perl notes for OS/2
253 perlos390 Perl notes for OS/390
254 perlos400 Perl notes for OS/400
255 perlplan9 Perl notes for Plan 9
256 perlqnx Perl notes for QNX
257 perlriscos Perl notes for RISC OS
258 perlsolaris Perl notes for Solaris
259 perlsymbian Perl notes for Symbian
260 perltru64 Perl notes for Tru64
261 perluts Perl notes for UTS
262 perlvmesa Perl notes for VM/ESA
263 perlvms Perl notes for VMS
264 perlvos Perl notes for Stratus VOS
265 perlwin32 Perl notes for Windows
268 On a Unix-like system, these documentation files will usually also be
269 available as manpages for use with the F<man> program.
271 In general, if something strange has gone wrong with your program and you're
272 not sure where you should look for help, try the B<-w> switch first. It will
273 often point out exactly where the trouble is.
277 Perl officially stands for Practical Extraction and Report Language,
278 except when it doesn't.
280 Perl was originally a language optimized for scanning arbitrary
281 text files, extracting information from those text files, and printing
282 reports based on that information. It quickly became a good language
283 for many system management tasks. Over the years, Perl has grown into
284 a general-purpose programming language. It's widely used for everything
285 from quick "one-liners" to full-scale application development.
287 The language is intended to be practical (easy to use, efficient,
288 complete) rather than beautiful (tiny, elegant, minimal).
290 Perl combines (in the author's opinion, anyway) some of the best
291 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
292 those languages should have little difficulty with it. (Language
293 historians will also note some vestiges of B<csh>, Pascal, and even
294 BASIC-PLUS.) Expression syntax corresponds closely to C
295 expression syntax. Unlike most Unix utilities, Perl does not
296 arbitrarily limit the size of your data--if you've got the memory,
297 Perl can slurp in your whole file as a single string. Recursion is of
298 unlimited depth. And the tables used by hashes (sometimes called
299 "associative arrays") grow as necessary to prevent degraded
300 performance. Perl can use sophisticated pattern matching techniques to
301 scan large amounts of data quickly. Although optimized for
302 scanning text, Perl also has many excellent tools for slicing
303 and dicing binary data.
305 But wait, there's more...
307 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
308 rewrite that provides the following additional benefits:
314 modularity and reusability using innumerable modules
316 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
320 embeddable and extensible
322 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
323 L<perlguts>, and L<xsubpp>.
327 roll-your-own magic variables (including multiple simultaneous DBM
330 Described in L<perltie> and L<AnyDBM_File>.
334 subroutines can now be overridden, autoloaded, and prototyped
336 Described in L<perlsub>.
340 arbitrarily nested data structures and anonymous functions
342 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
346 object-oriented programming
348 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
353 support for light-weight processes (threads)
355 Described in L<perlthrtut> and L<threads>.
359 support for Unicode, internationalization, and localization
361 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
367 Described in L<perlsub>.
371 regular expression enhancements
373 Described in L<perlre>, with additional examples in L<perlop>.
377 enhanced debugger and interactive Perl environment,
378 with integrated editor support
380 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
384 POSIX 1003.1 compliant library
386 Described in L<POSIX>.
390 Okay, that's I<definitely> enough hype.
394 Perl is available for most operating systems, including virtually
395 all Unix-like platforms. See L<perlport/"Supported Platforms">
404 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
406 If your Perl success stories and testimonials may be of help to others
407 who wish to advocate the use of Perl in their applications,
408 or if you wish to simply express your gratitude to Larry and the
409 Perl developers, please write to perl-thanks@perl.org .
413 "@INC" locations of perl libraries
417 http://www.perl.org/ the Perl homepage
418 http://www.perl.com/ Perl articles (O'Reilly)
419 http://www.cpan.org/ the Comprehensive Perl Archive
420 http://www.pm.org/ the Perl Mongers
424 The C<use warnings> pragma (and the B<-w> switch) produces some
427 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
428 diagnostics> pragma automatically turns Perl's normally terse warnings
429 and errors into these longer forms.
431 Compilation errors will tell you the line number of the error, with an
432 indication of the next token or token type that was to be examined.
433 (In a script passed to Perl via B<-e> switches, each
434 B<-e> is counted as one line.)
436 Setuid scripts have additional constraints that can produce error
437 messages such as "Insecure dependency". See L<perlsec>.
439 Did we mention that you should definitely consider using the B<-w>
444 The B<-w> switch is not mandatory.
446 Perl is at the mercy of your machine's definitions of various
447 operations such as type casting, atof(), and floating-point
448 output with sprintf().
450 If your stdio requires a seek or eof between reads and writes on a
451 particular stream, so does Perl. (This doesn't apply to sysread()
454 While none of the built-in data types have any arbitrary size limits
455 (apart from memory size), there are still a few arbitrary limits: a
456 given variable name may not be longer than 251 characters. Line numbers
457 displayed by diagnostics are internally stored as short integers,
458 so they are limited to a maximum of 65535 (higher numbers usually being
459 affected by wraparound).
461 You may mail your bug reports (be sure to include full configuration
462 information as output by the myconfig program in the perl source
463 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
464 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
465 can be used to help mail in a bug report.
467 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
468 don't tell anyone I said that.
472 The Perl motto is "There's more than one way to do it." Divining
473 how many more is left as an exercise to the reader.
475 The three principal virtues of a programmer are Laziness,
476 Impatience, and Hubris. See the Camel Book for why.