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 perlunitut Perl Unicode tutorial
101 perlebcdic Considerations for running Perl on EBCDIC platforms
103 perlsec Perl security
105 perlmod Perl modules: how they work
106 perlmodlib Perl modules: how to write and use
107 perlmodstyle Perl modules: how to write modules with style
108 perlmodinstall Perl modules: how to install from CPAN
109 perlnewmod Perl modules: preparing a new module for distribution
110 perlpragma Perl modules: writing a user pragma
112 perlutil utilities packaged with the Perl distribution
114 perlcompile Perl compiler suite intro
116 perlfilter Perl source filters
118 perlglossary Perl Glossary
120 =head2 Internals and C Language Interface
122 perlembed Perl ways to embed perl in your C or C++ application
123 perldebguts Perl debugging guts and tips
124 perlxstut Perl XS tutorial
125 perlxs Perl XS application programming interface
126 perlclib Internal replacements for standard C library functions
127 perlguts Perl internal functions for those doing extensions
128 perlcall Perl calling conventions from C
129 perlmroapi Perl method resolution plugin interface
130 perlreapi Perl regular expression plugin interface
131 perlreguts Perl regular expression engine internals
133 perlapi Perl API listing (autogenerated)
134 perlintern Perl internal functions (autogenerated)
135 perliol C API for Perl's implementation of IO in Layers
136 perlapio Perl internal IO abstraction interface
138 perlhack Perl hackers guide
139 perlpolicy Perl development policies
140 perlrepository Perl source repository
144 perlbook Perl book information
145 perlcommunity Perl community information
146 perltodo Perl things to do
148 perldoc Look up Perl documentation in Pod format
150 perlhist Perl history records
151 perldelta Perl changes since previous version
152 perl5110delta Perl changes in version 5.11.0
153 perl5101delta Perl changes in version 5.10.1
154 perl5100delta Perl changes in version 5.10.0
155 perl595delta Perl changes in version 5.9.5
156 perl594delta Perl changes in version 5.9.4
157 perl593delta Perl changes in version 5.9.3
158 perl592delta Perl changes in version 5.9.2
159 perl591delta Perl changes in version 5.9.1
160 perl590delta Perl changes in version 5.9.0
161 perl589delta Perl changes in version 5.8.9
162 perl588delta Perl changes in version 5.8.8
163 perl587delta Perl changes in version 5.8.7
164 perl586delta Perl changes in version 5.8.6
165 perl585delta Perl changes in version 5.8.5
166 perl584delta Perl changes in version 5.8.4
167 perl583delta Perl changes in version 5.8.3
168 perl582delta Perl changes in version 5.8.2
169 perl581delta Perl changes in version 5.8.1
170 perl58delta Perl changes in version 5.8.0
171 perl573delta Perl changes in version 5.7.3
172 perl572delta Perl changes in version 5.7.2
173 perl571delta Perl changes in version 5.7.1
174 perl570delta Perl changes in version 5.7.0
175 perl561delta Perl changes in version 5.6.1
176 perl56delta Perl changes in version 5.6
177 perl5005delta Perl changes in version 5.005
178 perl5004delta Perl changes in version 5.004
180 perlartistic Perl Artistic License
181 perlgpl GNU General Public License
183 =head2 Language-Specific
185 perlcn Perl for Simplified Chinese (in EUC-CN)
186 perljp Perl for Japanese (in EUC-JP)
187 perlko Perl for Korean (in EUC-KR)
188 perltw Perl for Traditional Chinese (in Big5)
190 =head2 Platform-Specific
192 perlaix Perl notes for AIX
193 perlamiga Perl notes for AmigaOS
194 perlapollo Perl notes for Apollo DomainOS
195 perlbeos Perl notes for BeOS
196 perlbs2000 Perl notes for POSIX-BC BS2000
197 perlce Perl notes for WinCE
198 perlcygwin Perl notes for Cygwin
199 perldgux Perl notes for DG/UX
200 perldos Perl notes for DOS
201 perlepoc Perl notes for EPOC
202 perlfreebsd Perl notes for FreeBSD
203 perlhaiku Perl notes for Haiku
204 perlhpux Perl notes for HP-UX
205 perlhurd Perl notes for Hurd
206 perlirix Perl notes for Irix
207 perllinux Perl notes for Linux
208 perlmacos Perl notes for Mac OS (Classic)
209 perlmacosx Perl notes for Mac OS X
210 perlmpeix Perl notes for MPE/iX
211 perlnetware Perl notes for NetWare
212 perlopenbsd Perl notes for OpenBSD
213 perlos2 Perl notes for OS/2
214 perlos390 Perl notes for OS/390
215 perlos400 Perl notes for OS/400
216 perlplan9 Perl notes for Plan 9
217 perlqnx Perl notes for QNX
218 perlriscos Perl notes for RISC OS
219 perlsolaris Perl notes for Solaris
220 perlsymbian Perl notes for Symbian
221 perltru64 Perl notes for Tru64
222 perluts Perl notes for UTS
223 perlvmesa Perl notes for VM/ESA
224 perlvms Perl notes for VMS
225 perlvos Perl notes for Stratus VOS
226 perlwin32 Perl notes for Windows
229 By default, the manpages listed above are installed in the
230 F</usr/local/man/> directory.
232 Extensive additional documentation for Perl modules is available. The
233 default configuration for perl will place this additional documentation
234 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
235 subdirectory of the Perl library directory). Some of this additional
236 documentation is distributed standard with Perl, but you'll also find
237 documentation for third-party modules there.
239 You should be able to view Perl's documentation with your man(1)
240 program by including the proper directories in the appropriate start-up
241 files, or in the MANPATH environment variable. To find out where the
242 configuration has installed the manpages, type:
246 If the directories have a common stem, such as F</usr/local/man/man1>
247 and F</usr/local/man/man3>, you need only to add that stem
248 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
249 environment variable. If they do not share a stem, you'll have to add
252 If that doesn't work for some reason, you can still use the
253 supplied F<perldoc> script to view module information. You might
254 also look into getting a replacement man program.
256 If something strange has gone wrong with your program and you're not
257 sure where you should look for help, try the B<-w> switch first. It
258 will often point out exactly where the trouble is.
262 Perl is a language optimized for scanning arbitrary
263 text files, extracting information from those text files, and printing
264 reports based on that information. It's also a good language for many
265 system management tasks. The language is intended to be practical
266 (easy to use, efficient, complete) rather than beautiful (tiny,
269 Perl combines (in the author's opinion, anyway) some of the best
270 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
271 those languages should have little difficulty with it. (Language
272 historians will also note some vestiges of B<csh>, Pascal, and even
273 BASIC-PLUS.) Expression syntax corresponds closely to C
274 expression syntax. Unlike most Unix utilities, Perl does not
275 arbitrarily limit the size of your data--if you've got the memory,
276 Perl can slurp in your whole file as a single string. Recursion is of
277 unlimited depth. And the tables used by hashes (sometimes called
278 "associative arrays") grow as necessary to prevent degraded
279 performance. Perl can use sophisticated pattern matching techniques to
280 scan large amounts of data quickly. Although optimized for
281 scanning text, Perl can also deal with binary data, and can make dbm
282 files look like hashes. Setuid Perl scripts are safer than C programs
283 through a dataflow tracing mechanism that prevents many stupid
286 If you have a problem that would ordinarily use B<sed> or B<awk> or
287 B<sh>, but it exceeds their capabilities or must run a little faster,
288 and you don't want to write the silly thing in C, then Perl may be for
289 you. There are also translators to turn your B<sed> and B<awk>
290 scripts into Perl scripts.
292 But wait, there's more...
294 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
295 rewrite that provides the following additional benefits:
301 modularity and reusability using innumerable modules
303 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
307 embeddable and extensible
309 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
310 L<perlguts>, and L<xsubpp>.
314 roll-your-own magic variables (including multiple simultaneous DBM
317 Described in L<perltie> and L<AnyDBM_File>.
321 subroutines can now be overridden, autoloaded, and prototyped
323 Described in L<perlsub>.
327 arbitrarily nested data structures and anonymous functions
329 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
333 object-oriented programming
335 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
340 support for light-weight processes (threads)
342 Described in L<perlthrtut> and L<threads>.
346 support for Unicode, internationalization, and localization
348 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
354 Described in L<perlsub>.
358 regular expression enhancements
360 Described in L<perlre>, with additional examples in L<perlop>.
364 enhanced debugger and interactive Perl environment,
365 with integrated editor support
367 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
371 POSIX 1003.1 compliant library
373 Described in L<POSIX>.
377 Okay, that's I<definitely> enough hype.
381 Perl is available for most operating systems, including virtually
382 all Unix-like platforms. See L<perlport/"Supported Platforms">
391 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
393 If your Perl success stories and testimonials may be of help to others
394 who wish to advocate the use of Perl in their applications,
395 or if you wish to simply express your gratitude to Larry and the
396 Perl developers, please write to perl-thanks@perl.org .
400 "@INC" locations of perl libraries
404 a2p awk to perl translator
405 s2p sed to perl translator
407 http://www.perl.org/ the Perl homepage
408 http://www.perl.com/ Perl articles (O'Reilly)
409 http://www.cpan.org/ the Comprehensive Perl Archive
410 http://www.pm.org/ the Perl Mongers
414 The C<use warnings> pragma (and the B<-w> switch) produces some
417 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
418 diagnostics> pragma automatically turns Perl's normally terse warnings
419 and errors into these longer forms.
421 Compilation errors will tell you the line number of the error, with an
422 indication of the next token or token type that was to be examined.
423 (In a script passed to Perl via B<-e> switches, each
424 B<-e> is counted as one line.)
426 Setuid scripts have additional constraints that can produce error
427 messages such as "Insecure dependency". See L<perlsec>.
429 Did we mention that you should definitely consider using the B<-w>
434 The B<-w> switch is not mandatory.
436 Perl is at the mercy of your machine's definitions of various
437 operations such as type casting, atof(), and floating-point
438 output with sprintf().
440 If your stdio requires a seek or eof between reads and writes on a
441 particular stream, so does Perl. (This doesn't apply to sysread()
444 While none of the built-in data types have any arbitrary size limits
445 (apart from memory size), there are still a few arbitrary limits: a
446 given variable name may not be longer than 251 characters. Line numbers
447 displayed by diagnostics are internally stored as short integers,
448 so they are limited to a maximum of 65535 (higher numbers usually being
449 affected by wraparound).
451 You may mail your bug reports (be sure to include full configuration
452 information as output by the myconfig program in the perl source
453 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
454 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
455 can be used to help mail in a bug report.
457 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
458 don't tell anyone I said that.
462 The Perl motto is "There's more than one way to do it." Divining
463 how many more is left as an exercise to the reader.
465 The three principal virtues of a programmer are Laziness,
466 Impatience, and Hubris. See the Camel Book for why.