3 perl - Practical Extraction and Report Language
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> ]...>
18 If you're new to Perl, you should start with L<perlintro>, which is a
19 general intro for beginners and provides some background to help you
20 navigate the rest of Perl's extensive documentation.
22 For ease of access, the Perl manual has been split up into several sections.
26 perl Perl overview (this section)
27 perlintro Perl introduction for beginners
28 perltoc Perl documentation table of contents
32 perlreftut Perl references short introduction
33 perldsc Perl data structures intro
34 perllol Perl data structures: arrays of arrays
36 perlrequick Perl regular expressions quick start
37 perlretut Perl regular expressions tutorial
39 perlboot Perl OO tutorial for beginners
40 perltoot Perl OO tutorial, part 1
41 perltooc Perl OO tutorial, part 2
42 perlbot Perl OO tricks and examples
44 perlperf Perl Performance and Optimization Techniques
46 perlstyle Perl style guide
48 perlcheat Perl cheat sheet
49 perltrap Perl traps for the unwary
50 perldebtut Perl debugging tutorial
52 perlfaq Perl frequently asked questions
53 perlfaq1 General Questions About Perl
54 perlfaq2 Obtaining and Learning about Perl
55 perlfaq3 Programming Tools
56 perlfaq4 Data Manipulation
57 perlfaq5 Files and Formats
59 perlfaq7 Perl Language Issues
60 perlfaq8 System Interaction
63 =head2 Reference Manual
66 perldata Perl data structures
67 perlop Perl operators and precedence
68 perlsub Perl subroutines
69 perlfunc Perl built-in functions
70 perlopentut Perl open() tutorial
71 perlpacktut Perl pack() and unpack() tutorial
72 perlpod Perl plain old documentation
73 perlpodspec Perl plain old documentation format specification
74 perlrun Perl execution and options
75 perldiag Perl diagnostic messages
76 perllexwarn Perl warnings and their control
77 perldebug Perl debugging
78 perlvar Perl predefined variables
79 perlre Perl regular expressions, the rest of the story
80 perlrebackslash Perl regular expression backslash sequences
81 perlrecharclass Perl regular expression character classes
82 perlreref Perl regular expressions quick reference
83 perlref Perl references, the rest of the story
86 perltie Perl objects hidden behind simple variables
87 perldbmfilter Perl DBM filters
89 perlipc Perl interprocess communication
90 perlfork Perl fork() information
91 perlnumber Perl number semantics
93 perlthrtut Perl threads tutorial
95 perlport Perl portability guide
96 perllocale Perl locale support
97 perluniintro Perl Unicode introduction
98 perlunicode Perl Unicode support
99 perlunifaq Perl Unicode FAQ
100 perluniprops Complete index of Unicode Version 5.1.0 properties
101 perlunitut Perl Unicode tutorial
102 perlebcdic Considerations for running Perl on EBCDIC platforms
104 perlsec Perl security
106 perlmod Perl modules: how they work
107 perlmodlib Perl modules: how to write and use
108 perlmodstyle Perl modules: how to write modules with style
109 perlmodinstall Perl modules: how to install from CPAN
110 perlnewmod Perl modules: preparing a new module for distribution
111 perlpragma Perl modules: writing a user pragma
113 perlutil utilities packaged with the Perl distribution
115 perlcompile Perl compiler suite intro
117 perlfilter Perl source filters
119 perlglossary Perl Glossary
121 =head2 Internals and C Language Interface
123 perlembed Perl ways to embed perl in your C or C++ application
124 perldebguts Perl debugging guts and tips
125 perlxstut Perl XS tutorial
126 perlxs Perl XS application programming interface
127 perlclib Internal replacements for standard C library functions
128 perlguts Perl internal functions for those doing extensions
129 perlcall Perl calling conventions from C
130 perlmroapi Perl method resolution plugin interface
131 perlreapi Perl regular expression plugin interface
132 perlreguts Perl regular expression engine internals
134 perlapi Perl API listing (autogenerated)
135 perlintern Perl internal functions (autogenerated)
136 perliol C API for Perl's implementation of IO in Layers
137 perlapio Perl internal IO abstraction interface
139 perlhack Perl hackers guide
140 perlpolicy Perl development policies
141 perlrepository Perl source repository
145 perlbook Perl book information
146 perlcommunity Perl community information
147 perltodo Perl things to do
149 perldoc Look up Perl documentation in Pod format
151 perlhist Perl history records
152 perl5120delta Perl changes in version 5.12.0
153 perldelta Perl changes since previous version
154 perl5114delta Perl changes in version 5.11.4
155 perl5113delta Perl changes in version 5.11.3
156 perl5112delta Perl changes in version 5.11.2
157 perl5111delta Perl changes in version 5.11.1
158 perl5110delta Perl changes in version 5.11.0
159 perl5101delta Perl changes in version 5.10.1
160 perl5100delta Perl changes in version 5.10.0
161 perl595delta Perl changes in version 5.9.5
162 perl594delta Perl changes in version 5.9.4
163 perl593delta Perl changes in version 5.9.3
164 perl592delta Perl changes in version 5.9.2
165 perl591delta Perl changes in version 5.9.1
166 perl590delta Perl changes in version 5.9.0
167 perl589delta Perl changes in version 5.8.9
168 perl588delta Perl changes in version 5.8.8
169 perl587delta Perl changes in version 5.8.7
170 perl586delta Perl changes in version 5.8.6
171 perl585delta Perl changes in version 5.8.5
172 perl584delta Perl changes in version 5.8.4
173 perl583delta Perl changes in version 5.8.3
174 perl582delta Perl changes in version 5.8.2
175 perl581delta Perl changes in version 5.8.1
176 perl58delta Perl changes in version 5.8.0
177 perl573delta Perl changes in version 5.7.3
178 perl572delta Perl changes in version 5.7.2
179 perl571delta Perl changes in version 5.7.1
180 perl570delta Perl changes in version 5.7.0
181 perl561delta Perl changes in version 5.6.1
182 perl56delta Perl changes in version 5.6
183 perl5005delta Perl changes in version 5.005
184 perl5004delta Perl changes in version 5.004
186 perlartistic Perl Artistic License
187 perlgpl GNU General Public License
189 =head2 Language-Specific
191 perlcn Perl for Simplified Chinese (in EUC-CN)
192 perljp Perl for Japanese (in EUC-JP)
193 perlko Perl for Korean (in EUC-KR)
194 perltw Perl for Traditional Chinese (in Big5)
196 =head2 Platform-Specific
198 perlaix Perl notes for AIX
199 perlamiga Perl notes for AmigaOS
200 perlapollo Perl notes for Apollo DomainOS
201 perlbeos Perl notes for BeOS
202 perlbs2000 Perl notes for POSIX-BC BS2000
203 perlce Perl notes for WinCE
204 perlcygwin Perl notes for Cygwin
205 perldgux Perl notes for DG/UX
206 perldos Perl notes for DOS
207 perlepoc Perl notes for EPOC
208 perlfreebsd Perl notes for FreeBSD
209 perlhaiku Perl notes for Haiku
210 perlhpux Perl notes for HP-UX
211 perlhurd Perl notes for Hurd
212 perlirix Perl notes for Irix
213 perllinux Perl notes for Linux
214 perlmacos Perl notes for Mac OS (Classic)
215 perlmacosx Perl notes for Mac OS X
216 perlmpeix Perl notes for MPE/iX
217 perlnetware Perl notes for NetWare
218 perlopenbsd Perl notes for OpenBSD
219 perlos2 Perl notes for OS/2
220 perlos390 Perl notes for OS/390
221 perlos400 Perl notes for OS/400
222 perlplan9 Perl notes for Plan 9
223 perlqnx Perl notes for QNX
224 perlriscos Perl notes for RISC OS
225 perlsolaris Perl notes for Solaris
226 perlsymbian Perl notes for Symbian
227 perltru64 Perl notes for Tru64
228 perluts Perl notes for UTS
229 perlvmesa Perl notes for VM/ESA
230 perlvms Perl notes for VMS
231 perlvos Perl notes for Stratus VOS
232 perlwin32 Perl notes for Windows
235 By default, the manpages listed above are installed in the
236 F</usr/local/man/> directory.
238 Extensive additional documentation for Perl modules is available. The
239 default configuration for perl will place this additional documentation
240 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
241 subdirectory of the Perl library directory). Some of this additional
242 documentation is distributed standard with Perl, but you'll also find
243 documentation for third-party modules there.
245 You should be able to view Perl's documentation with your man(1)
246 program by including the proper directories in the appropriate start-up
247 files, or in the MANPATH environment variable. To find out where the
248 configuration has installed the manpages, type:
252 If the directories have a common stem, such as F</usr/local/man/man1>
253 and F</usr/local/man/man3>, you need only to add that stem
254 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
255 environment variable. If they do not share a stem, you'll have to add
258 If that doesn't work for some reason, you can still use the
259 supplied F<perldoc> script to view module information. You might
260 also look into getting a replacement man program.
262 If something strange has gone wrong with your program and you're not
263 sure where you should look for help, try the B<-w> switch first. It
264 will often point out exactly where the trouble is.
268 Perl is a language optimized for scanning arbitrary
269 text files, extracting information from those text files, and printing
270 reports based on that information. It's also a good language for many
271 system management tasks. The language is intended to be practical
272 (easy to use, efficient, complete) rather than beautiful (tiny,
275 Perl combines (in the author's opinion, anyway) some of the best
276 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
277 those languages should have little difficulty with it. (Language
278 historians will also note some vestiges of B<csh>, Pascal, and even
279 BASIC-PLUS.) Expression syntax corresponds closely to C
280 expression syntax. Unlike most Unix utilities, Perl does not
281 arbitrarily limit the size of your data--if you've got the memory,
282 Perl can slurp in your whole file as a single string. Recursion is of
283 unlimited depth. And the tables used by hashes (sometimes called
284 "associative arrays") grow as necessary to prevent degraded
285 performance. Perl can use sophisticated pattern matching techniques to
286 scan large amounts of data quickly. Although optimized for
287 scanning text, Perl can also deal with binary data, and can make dbm
288 files look like hashes. Setuid Perl scripts are safer than C programs
289 through a dataflow tracing mechanism that prevents many stupid
292 If you have a problem that would ordinarily use B<sed> or B<awk> or
293 B<sh>, but it exceeds their capabilities or must run a little faster,
294 and you don't want to write the silly thing in C, then Perl may be for
295 you. There are also translators to turn your B<sed> and B<awk>
296 scripts into Perl scripts.
298 But wait, there's more...
300 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
301 rewrite that provides the following additional benefits:
307 modularity and reusability using innumerable modules
309 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
313 embeddable and extensible
315 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
316 L<perlguts>, and L<xsubpp>.
320 roll-your-own magic variables (including multiple simultaneous DBM
323 Described in L<perltie> and L<AnyDBM_File>.
327 subroutines can now be overridden, autoloaded, and prototyped
329 Described in L<perlsub>.
333 arbitrarily nested data structures and anonymous functions
335 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
339 object-oriented programming
341 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
346 support for light-weight processes (threads)
348 Described in L<perlthrtut> and L<threads>.
352 support for Unicode, internationalization, and localization
354 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
360 Described in L<perlsub>.
364 regular expression enhancements
366 Described in L<perlre>, with additional examples in L<perlop>.
370 enhanced debugger and interactive Perl environment,
371 with integrated editor support
373 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
377 POSIX 1003.1 compliant library
379 Described in L<POSIX>.
383 Okay, that's I<definitely> enough hype.
387 Perl is available for most operating systems, including virtually
388 all Unix-like platforms. See L<perlport/"Supported Platforms">
397 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
399 If your Perl success stories and testimonials may be of help to others
400 who wish to advocate the use of Perl in their applications,
401 or if you wish to simply express your gratitude to Larry and the
402 Perl developers, please write to perl-thanks@perl.org .
406 "@INC" locations of perl libraries
410 a2p awk to perl translator
411 s2p sed to perl translator
413 http://www.perl.org/ the Perl homepage
414 http://www.perl.com/ Perl articles (O'Reilly)
415 http://www.cpan.org/ the Comprehensive Perl Archive
416 http://www.pm.org/ the Perl Mongers
420 The C<use warnings> pragma (and the B<-w> switch) produces some
423 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
424 diagnostics> pragma automatically turns Perl's normally terse warnings
425 and errors into these longer forms.
427 Compilation errors will tell you the line number of the error, with an
428 indication of the next token or token type that was to be examined.
429 (In a script passed to Perl via B<-e> switches, each
430 B<-e> is counted as one line.)
432 Setuid scripts have additional constraints that can produce error
433 messages such as "Insecure dependency". See L<perlsec>.
435 Did we mention that you should definitely consider using the B<-w>
440 The B<-w> switch is not mandatory.
442 Perl is at the mercy of your machine's definitions of various
443 operations such as type casting, atof(), and floating-point
444 output with sprintf().
446 If your stdio requires a seek or eof between reads and writes on a
447 particular stream, so does Perl. (This doesn't apply to sysread()
450 While none of the built-in data types have any arbitrary size limits
451 (apart from memory size), there are still a few arbitrary limits: a
452 given variable name may not be longer than 251 characters. Line numbers
453 displayed by diagnostics are internally stored as short integers,
454 so they are limited to a maximum of 65535 (higher numbers usually being
455 affected by wraparound).
457 You may mail your bug reports (be sure to include full configuration
458 information as output by the myconfig program in the perl source
459 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
460 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
461 can be used to help mail in a bug report.
463 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
464 don't tell anyone I said that.
468 The Perl motto is "There's more than one way to do it." Divining
469 how many more is left as an exercise to the reader.
471 The three principal virtues of a programmer are Laziness,
472 Impatience, and Hubris. See the Camel Book for why.