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 perlrepository Perl source repository
143 perlbook Perl book information
144 perlcommunity Perl community information
145 perltodo Perl things to do
147 perldoc Look up Perl documentation in Pod format
149 perlhist Perl history records
150 perldelta Perl changes since previous version
151 perl5100delta Perl changes in version 5.10.0
152 perl595delta Perl changes in version 5.9.5
153 perl594delta Perl changes in version 5.9.4
154 perl593delta Perl changes in version 5.9.3
155 perl592delta Perl changes in version 5.9.2
156 perl591delta Perl changes in version 5.9.1
157 perl590delta Perl changes in version 5.9.0
158 perl589delta Perl changes in version 5.8.9
159 perl588delta Perl changes in version 5.8.8
160 perl587delta Perl changes in version 5.8.7
161 perl586delta Perl changes in version 5.8.6
162 perl585delta Perl changes in version 5.8.5
163 perl584delta Perl changes in version 5.8.4
164 perl583delta Perl changes in version 5.8.3
165 perl582delta Perl changes in version 5.8.2
166 perl581delta Perl changes in version 5.8.1
167 perl58delta Perl changes in version 5.8.0
168 perl573delta Perl changes in version 5.7.3
169 perl572delta Perl changes in version 5.7.2
170 perl571delta Perl changes in version 5.7.1
171 perl570delta Perl changes in version 5.7.0
172 perl561delta Perl changes in version 5.6.1
173 perl56delta Perl changes in version 5.6
174 perl5005delta Perl changes in version 5.005
175 perl5004delta Perl changes in version 5.004
177 perlartistic Perl Artistic License
178 perlgpl GNU General Public License
180 =head2 Language-Specific
182 perlcn Perl for Simplified Chinese (in EUC-CN)
183 perljp Perl for Japanese (in EUC-JP)
184 perlko Perl for Korean (in EUC-KR)
185 perltw Perl for Traditional Chinese (in Big5)
187 =head2 Platform-Specific
189 perlaix Perl notes for AIX
190 perlamiga Perl notes for AmigaOS
191 perlapollo Perl notes for Apollo DomainOS
192 perlbeos Perl notes for BeOS
193 perlbs2000 Perl notes for POSIX-BC BS2000
194 perlce Perl notes for WinCE
195 perlcygwin Perl notes for Cygwin
196 perldgux Perl notes for DG/UX
197 perldos Perl notes for DOS
198 perlepoc Perl notes for EPOC
199 perlfreebsd Perl notes for FreeBSD
200 perlhaiku Perl notes for Haiku
201 perlhpux Perl notes for HP-UX
202 perlhurd Perl notes for Hurd
203 perlirix Perl notes for Irix
204 perllinux Perl notes for Linux
205 perlmacos Perl notes for Mac OS (Classic)
206 perlmacosx Perl notes for Mac OS X
207 perlmpeix Perl notes for MPE/iX
208 perlnetware Perl notes for NetWare
209 perlopenbsd Perl notes for OpenBSD
210 perlos2 Perl notes for OS/2
211 perlos390 Perl notes for OS/390
212 perlos400 Perl notes for OS/400
213 perlplan9 Perl notes for Plan 9
214 perlqnx Perl notes for QNX
215 perlriscos Perl notes for RISC OS
216 perlsolaris Perl notes for Solaris
217 perlsymbian Perl notes for Symbian
218 perltru64 Perl notes for Tru64
219 perluts Perl notes for UTS
220 perlvmesa Perl notes for VM/ESA
221 perlvms Perl notes for VMS
222 perlvos Perl notes for Stratus VOS
223 perlwin32 Perl notes for Windows
226 By default, the manpages listed above are installed in the
227 F</usr/local/man/> directory.
229 Extensive additional documentation for Perl modules is available. The
230 default configuration for perl will place this additional documentation
231 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
232 subdirectory of the Perl library directory). Some of this additional
233 documentation is distributed standard with Perl, but you'll also find
234 documentation for third-party modules there.
236 You should be able to view Perl's documentation with your man(1)
237 program by including the proper directories in the appropriate start-up
238 files, or in the MANPATH environment variable. To find out where the
239 configuration has installed the manpages, type:
243 If the directories have a common stem, such as F</usr/local/man/man1>
244 and F</usr/local/man/man3>, you need only to add that stem
245 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
246 environment variable. If they do not share a stem, you'll have to add
249 If that doesn't work for some reason, you can still use the
250 supplied F<perldoc> script to view module information. You might
251 also look into getting a replacement man program.
253 If something strange has gone wrong with your program and you're not
254 sure where you should look for help, try the B<-w> switch first. It
255 will often point out exactly where the trouble is.
259 Perl is a language optimized for scanning arbitrary
260 text files, extracting information from those text files, and printing
261 reports based on that information. It's also a good language for many
262 system management tasks. The language is intended to be practical
263 (easy to use, efficient, complete) rather than beautiful (tiny,
266 Perl combines (in the author's opinion, anyway) some of the best
267 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
268 those languages should have little difficulty with it. (Language
269 historians will also note some vestiges of B<csh>, Pascal, and even
270 BASIC-PLUS.) Expression syntax corresponds closely to C
271 expression syntax. Unlike most Unix utilities, Perl does not
272 arbitrarily limit the size of your data--if you've got the memory,
273 Perl can slurp in your whole file as a single string. Recursion is of
274 unlimited depth. And the tables used by hashes (sometimes called
275 "associative arrays") grow as necessary to prevent degraded
276 performance. Perl can use sophisticated pattern matching techniques to
277 scan large amounts of data quickly. Although optimized for
278 scanning text, Perl can also deal with binary data, and can make dbm
279 files look like hashes. Setuid Perl scripts are safer than C programs
280 through a dataflow tracing mechanism that prevents many stupid
283 If you have a problem that would ordinarily use B<sed> or B<awk> or
284 B<sh>, but it exceeds their capabilities or must run a little faster,
285 and you don't want to write the silly thing in C, then Perl may be for
286 you. There are also translators to turn your B<sed> and B<awk>
287 scripts into Perl scripts.
289 But wait, there's more...
291 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
292 rewrite that provides the following additional benefits:
298 modularity and reusability using innumerable modules
300 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
304 embeddable and extensible
306 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
307 L<perlguts>, and L<xsubpp>.
311 roll-your-own magic variables (including multiple simultaneous DBM
314 Described in L<perltie> and L<AnyDBM_File>.
318 subroutines can now be overridden, autoloaded, and prototyped
320 Described in L<perlsub>.
324 arbitrarily nested data structures and anonymous functions
326 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
330 object-oriented programming
332 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
337 support for light-weight processes (threads)
339 Described in L<perlthrtut> and L<threads>.
343 support for Unicode, internationalization, and localization
345 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
351 Described in L<perlsub>.
355 regular expression enhancements
357 Described in L<perlre>, with additional examples in L<perlop>.
361 enhanced debugger and interactive Perl environment,
362 with integrated editor support
364 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
368 POSIX 1003.1 compliant library
370 Described in L<POSIX>.
374 Okay, that's I<definitely> enough hype.
378 Perl is available for most operating systems, including virtually
379 all Unix-like platforms. See L<perlport/"Supported Platforms">
388 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
390 If your Perl success stories and testimonials may be of help to others
391 who wish to advocate the use of Perl in their applications,
392 or if you wish to simply express your gratitude to Larry and the
393 Perl developers, please write to perl-thanks@perl.org .
397 "@INC" locations of perl libraries
401 a2p awk to perl translator
402 s2p sed to perl translator
404 http://www.perl.org/ the Perl homepage
405 http://www.perl.com/ Perl articles (O'Reilly)
406 http://www.cpan.org/ the Comprehensive Perl Archive
407 http://www.pm.org/ the Perl Mongers
411 The C<use warnings> pragma (and the B<-w> switch) produces some
414 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
415 diagnostics> pragma automatically turns Perl's normally terse warnings
416 and errors into these longer forms.
418 Compilation errors will tell you the line number of the error, with an
419 indication of the next token or token type that was to be examined.
420 (In a script passed to Perl via B<-e> switches, each
421 B<-e> is counted as one line.)
423 Setuid scripts have additional constraints that can produce error
424 messages such as "Insecure dependency". See L<perlsec>.
426 Did we mention that you should definitely consider using the B<-w>
431 The B<-w> switch is not mandatory.
433 Perl is at the mercy of your machine's definitions of various
434 operations such as type casting, atof(), and floating-point
435 output with sprintf().
437 If your stdio requires a seek or eof between reads and writes on a
438 particular stream, so does Perl. (This doesn't apply to sysread()
441 While none of the built-in data types have any arbitrary size limits
442 (apart from memory size), there are still a few arbitrary limits: a
443 given variable name may not be longer than 251 characters. Line numbers
444 displayed by diagnostics are internally stored as short integers,
445 so they are limited to a maximum of 65535 (higher numbers usually being
446 affected by wraparound).
448 You may mail your bug reports (be sure to include full configuration
449 information as output by the myconfig program in the perl source
450 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
451 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
452 can be used to help mail in a bug report.
454 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
455 don't tell anyone I said that.
459 The Perl motto is "There's more than one way to do it." Divining
460 how many more is left as an exercise to the reader.
462 The three principal virtues of a programmer are Laziness,
463 Impatience, and Hubris. See the Camel Book for why.