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 perlootut Perl OO tutorial for beginners
48 perlperf Perl Performance and Optimization Techniques
50 perlstyle Perl style guide
52 perlcheat Perl cheat sheet
53 perltrap Perl traps for the unwary
54 perldebtut Perl debugging tutorial
56 perlfaq Perl frequently asked questions
57 perlfaq1 General Questions About Perl
58 perlfaq2 Obtaining and Learning about Perl
59 perlfaq3 Programming Tools
60 perlfaq4 Data Manipulation
61 perlfaq5 Files and Formats
63 perlfaq7 Perl Language Issues
64 perlfaq8 System Interaction
67 =head2 Reference Manual
70 perldata Perl data structures
71 perlop Perl operators and precedence
72 perlsub Perl subroutines
73 perlfunc Perl built-in functions
74 perlopentut Perl open() tutorial
75 perlpacktut Perl pack() and unpack() tutorial
76 perlpod Perl plain old documentation
77 perlpodspec Perl plain old documentation format specification
78 perlpodstyle Perl POD style guide
79 perlrun Perl execution and options
80 perldiag Perl diagnostic messages
81 perllexwarn Perl warnings and their control
82 perldebug Perl debugging
83 perlvar Perl predefined variables
84 perlre Perl regular expressions, the rest of the story
85 perlrebackslash Perl regular expression backslash sequences
86 perlrecharclass Perl regular expression character classes
87 perlreref Perl regular expressions quick reference
88 perlref Perl references, the rest of the story
91 perltie Perl objects hidden behind simple variables
92 perldbmfilter Perl DBM filters
94 perlipc Perl interprocess communication
95 perlfork Perl fork() information
96 perlnumber Perl number semantics
98 perlthrtut Perl threads tutorial
100 perlport Perl portability guide
101 perllocale Perl locale support
102 perluniintro Perl Unicode introduction
103 perlunicode Perl Unicode support
104 perlunifaq Perl Unicode FAQ
105 perluniprops Index of Unicode Version 6.0.0 properties in Perl
106 perlunitut Perl Unicode tutorial
107 perlebcdic Considerations for running Perl on EBCDIC platforms
109 perlsec Perl security
111 perlmod Perl modules: how they work
112 perlmodlib Perl modules: how to write and use
113 perlmodstyle Perl modules: how to write modules with style
114 perlmodinstall Perl modules: how to install from CPAN
115 perlnewmod Perl modules: preparing a new module for distribution
116 perlpragma Perl modules: writing a user pragma
118 perlutil utilities packaged with the Perl distribution
120 perlfilter Perl source filters
122 perldtrace Perl's support for DTrace
124 perlglossary Perl Glossary
126 =head2 Internals and C Language Interface
128 perlembed Perl ways to embed perl in your C or C++ application
129 perldebguts Perl debugging guts and tips
130 perlxstut Perl XS tutorial
131 perlxs Perl XS application programming interface
132 perlclib Internal replacements for standard C library functions
133 perlguts Perl internal functions for those doing extensions
134 perlcall Perl calling conventions from C
135 perlmroapi Perl method resolution plugin interface
136 perlreapi Perl regular expression plugin interface
137 perlreguts Perl regular expression engine internals
139 perlapi Perl API listing (autogenerated)
140 perlintern Perl internal functions (autogenerated)
141 perliol C API for Perl's implementation of IO in Layers
142 perlapio Perl internal IO abstraction interface
144 perlhack Perl hackers guide
145 perlsource Guide to the Perl source tree
146 perlinterp Overview of the Perl interpreter source and how it works
147 perlhacktut Walk through the creation of a simple C code patch
148 perlhacktips Tips for Perl core C code hacking
149 perlpolicy Perl development policies
150 perlgit Using git with the Perl repository
154 perlbook Perl book information
155 perlcommunity Perl community information
156 perltodo Perl things to do
158 perldoc Look up Perl documentation in Pod format
160 perlhist Perl history records
161 perldelta Perl changes since previous version
162 perl5152delta Perl changes in version 5.15.2
163 perl5151delta Perl changes in version 5.15.1
164 perl5150delta Perl changes in version 5.15.0
165 perl5141delta Perl changes in version 5.14.1
166 perl5140delta Perl changes in version 5.14.0
167 perl5124delta Perl changes in version 5.12.4
168 perl5123delta Perl changes in version 5.12.3
169 perl5122delta Perl changes in version 5.12.2
170 perl5121delta Perl changes in version 5.12.1
171 perl5120delta Perl changes in version 5.12.0
172 perl5101delta Perl changes in version 5.10.1
173 perl5100delta Perl changes in version 5.10.0
174 perl589delta Perl changes in version 5.8.9
175 perl588delta Perl changes in version 5.8.8
176 perl587delta Perl changes in version 5.8.7
177 perl586delta Perl changes in version 5.8.6
178 perl585delta Perl changes in version 5.8.5
179 perl584delta Perl changes in version 5.8.4
180 perl583delta Perl changes in version 5.8.3
181 perl582delta Perl changes in version 5.8.2
182 perl581delta Perl changes in version 5.8.1
183 perl58delta Perl changes in version 5.8.0
184 perl561delta Perl changes in version 5.6.1
185 perl56delta Perl changes in version 5.6
186 perl5005delta Perl changes in version 5.005
187 perl5004delta Perl changes in version 5.004
189 perlexperiment A listing of experimental features in Perl
191 perlartistic Perl Artistic License
192 perlgpl GNU General Public License
194 =head2 Language-Specific
196 perlcn Perl for Simplified Chinese (in EUC-CN)
197 perljp Perl for Japanese (in EUC-JP)
198 perlko Perl for Korean (in EUC-KR)
199 perltw Perl for Traditional Chinese (in Big5)
201 =head2 Platform-Specific
203 perlaix Perl notes for AIX
204 perlamiga Perl notes for AmigaOS
205 perlbeos Perl notes for BeOS
206 perlbs2000 Perl notes for POSIX-BC BS2000
207 perlce Perl notes for WinCE
208 perlcygwin Perl notes for Cygwin
209 perldgux Perl notes for DG/UX
210 perldos Perl notes for DOS
211 perlepoc Perl notes for EPOC
212 perlfreebsd Perl notes for FreeBSD
213 perlhaiku Perl notes for Haiku
214 perlhpux Perl notes for HP-UX
215 perlhurd Perl notes for Hurd
216 perlirix Perl notes for Irix
217 perllinux Perl notes for Linux
218 perlmacos Perl notes for Mac OS (Classic)
219 perlmacosx Perl notes for Mac OS X
220 perlmpeix Perl notes for MPE/iX
221 perlnetware Perl notes for NetWare
222 perlopenbsd Perl notes for OpenBSD
223 perlos2 Perl notes for OS/2
224 perlos390 Perl notes for OS/390
225 perlos400 Perl notes for OS/400
226 perlplan9 Perl notes for Plan 9
227 perlqnx Perl notes for QNX
228 perlriscos Perl notes for RISC OS
229 perlsolaris Perl notes for Solaris
230 perlsymbian Perl notes for Symbian
231 perltru64 Perl notes for Tru64
232 perluts Perl notes for UTS
233 perlvmesa Perl notes for VM/ESA
234 perlvms Perl notes for VMS
235 perlvos Perl notes for Stratus VOS
236 perlwin32 Perl notes for Windows
239 On a Unix-like system, these documentation files will usually also be
240 available as manpages for use with the F<man> program.
242 In general, if something strange has gone wrong with your program and you're
243 not sure where you should look for help, try the B<-w> switch first. It will
244 often point out exactly where the trouble is.
248 Perl officially stands for Practical Extraction and Report Language,
249 except when it doesn't.
251 Perl was originally a language optimized for scanning arbitrary
252 text files, extracting information from those text files, and printing
253 reports based on that information. It quickly became a good language
254 for many system management tasks. Over the years, Perl has grown into
255 a general-purpose programming language. It's widely used for everything
256 from quick "one-liners" to full-scale application development.
258 The language is intended to be practical (easy to use, efficient,
259 complete) rather than beautiful (tiny, elegant, minimal).
261 Perl combines (in the author's opinion, anyway) some of the best
262 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
263 those languages should have little difficulty with it. (Language
264 historians will also note some vestiges of B<csh>, Pascal, and even
265 BASIC-PLUS.) Expression syntax corresponds closely to C
266 expression syntax. Unlike most Unix utilities, Perl does not
267 arbitrarily limit the size of your data--if you've got the memory,
268 Perl can slurp in your whole file as a single string. Recursion is of
269 unlimited depth. And the tables used by hashes (sometimes called
270 "associative arrays") grow as necessary to prevent degraded
271 performance. Perl can use sophisticated pattern matching techniques to
272 scan large amounts of data quickly. Although optimized for
273 scanning text, Perl also has many excellent tools for slicing
274 and dicing binary data.
276 But wait, there's more...
278 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
279 rewrite that provides the following additional benefits:
285 modularity and reusability using innumerable modules
287 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
291 embeddable and extensible
293 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
294 L<perlguts>, and L<xsubpp>.
298 roll-your-own magic variables (including multiple simultaneous DBM
301 Described in L<perltie> and L<AnyDBM_File>.
305 subroutines can now be overridden, autoloaded, and prototyped
307 Described in L<perlsub>.
311 arbitrarily nested data structures and anonymous functions
313 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
317 object-oriented programming
319 Described in L<perlobj> and L<perlootut>.
323 support for light-weight processes (threads)
325 Described in L<perlthrtut> and L<threads>.
329 support for Unicode, internationalization, and localization
331 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
337 Described in L<perlsub>.
341 regular expression enhancements
343 Described in L<perlre>, with additional examples in L<perlop>.
347 enhanced debugger and interactive Perl environment,
348 with integrated editor support
350 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
354 POSIX 1003.1 compliant library
356 Described in L<POSIX>.
360 Okay, that's I<definitely> enough hype.
364 Perl is available for most operating systems, including virtually
365 all Unix-like platforms. See L<perlport/"Supported Platforms">
374 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
376 If your Perl success stories and testimonials may be of help to others
377 who wish to advocate the use of Perl in their applications,
378 or if you wish to simply express your gratitude to Larry and the
379 Perl developers, please write to perl-thanks@perl.org .
383 "@INC" locations of perl libraries
387 http://www.perl.org/ the Perl homepage
388 http://www.perl.com/ Perl articles (O'Reilly)
389 http://www.cpan.org/ the Comprehensive Perl Archive
390 http://www.pm.org/ the Perl Mongers
394 The C<use warnings> pragma (and the B<-w> switch) produces some
397 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
398 diagnostics> pragma automatically turns Perl's normally terse warnings
399 and errors into these longer forms.
401 Compilation errors will tell you the line number of the error, with an
402 indication of the next token or token type that was to be examined.
403 (In a script passed to Perl via B<-e> switches, each
404 B<-e> is counted as one line.)
406 Setuid scripts have additional constraints that can produce error
407 messages such as "Insecure dependency". See L<perlsec>.
409 Did we mention that you should definitely consider using the B<-w>
414 The B<-w> switch is not mandatory.
416 Perl is at the mercy of your machine's definitions of various
417 operations such as type casting, atof(), and floating-point
418 output with sprintf().
420 If your stdio requires a seek or eof between reads and writes on a
421 particular stream, so does Perl. (This doesn't apply to sysread()
424 While none of the built-in data types have any arbitrary size limits
425 (apart from memory size), there are still a few arbitrary limits: a
426 given variable name may not be longer than 251 characters. Line numbers
427 displayed by diagnostics are internally stored as short integers,
428 so they are limited to a maximum of 65535 (higher numbers usually being
429 affected by wraparound).
431 You may mail your bug reports (be sure to include full configuration
432 information as output by the myconfig program in the perl source
433 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
434 in compiling perl, the L<perlbug> script in the F<utils/> subdirectory
435 can be used to help mail in a bug report.
437 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
438 don't tell anyone I said that.
442 The Perl motto is "There's more than one way to do it." Divining
443 how many more is left as an exercise to the reader.
445 The three principal virtues of a programmer are Laziness,
446 Impatience, and Hubris. See the Camel Book for why.