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>] >]>
16 S<[ B<-i>[I<extension>] ]>
17 S<[ B<-e> I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...>
19 If you're new to Perl, you should start with L<perlintro>, which is a
20 general intro for beginners and provides some background to help you
21 navigate the rest of Perl's extensive documentation.
23 For ease of access, the Perl manual has been split up into several sections.
27 perl Perl overview (this section)
28 perlintro Perl introduction for beginners
29 perltoc Perl documentation table of contents
33 perlreftut Perl references short introduction
34 perldsc Perl data structures intro
35 perllol Perl data structures: arrays of arrays
37 perlrequick Perl regular expressions quick start
38 perlretut Perl regular expressions tutorial
40 perlboot Perl OO tutorial for beginners
41 perltoot Perl OO tutorial, part 1
42 perltooc Perl OO tutorial, part 2
43 perlbot Perl OO tricks and examples
45 perlstyle Perl style guide
47 perlcheat Perl cheat sheet
48 perltrap Perl traps for the unwary
49 perldebtut Perl debugging tutorial
51 perlfaq Perl frequently asked questions
52 perlfaq1 General Questions About Perl
53 perlfaq2 Obtaining and Learning about Perl
54 perlfaq3 Programming Tools
55 perlfaq4 Data Manipulation
56 perlfaq5 Files and Formats
58 perlfaq7 Perl Language Issues
59 perlfaq8 System Interaction
62 =head2 Reference Manual
65 perldata Perl data structures
66 perlop Perl operators and precedence
67 perlsub Perl subroutines
68 perlfunc Perl built-in functions
69 perlopentut Perl open() tutorial
70 perlpacktut Perl pack() and unpack() tutorial
71 perlpod Perl plain old documentation
72 perlpodspec Perl plain old documentation format specification
73 perlrun Perl execution and options
74 perldiag Perl diagnostic messages
75 perllexwarn Perl warnings and their control
76 perldebug Perl debugging
77 perlvar Perl predefined variables
78 perlre Perl regular expressions, the rest of the story
79 perlrebackslash Perl regular expression backslash sequences
80 perlrecharclass Perl regular expression character classes
81 perlreref Perl regular expressions quick reference
82 perlref Perl references, the rest of the story
85 perltie Perl objects hidden behind simple variables
86 perldbmfilter Perl DBM filters
88 perlipc Perl interprocess communication
89 perlfork Perl fork() information
90 perlnumber Perl number semantics
92 perlthrtut Perl threads tutorial
93 perlothrtut Old 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 perlreapi Perl regular expression plugin interface
130 perlreguts Perl regular expression engine internals
132 perlapi Perl API listing (autogenerated)
133 perlintern Perl internal functions (autogenerated)
134 perliol C API for Perl's implementation of IO in Layers
135 perlapio Perl internal IO abstraction interface
137 perlhack Perl hackers guide
141 perlbook Perl book information
142 perltodo Perl things to do
144 perldoc Look up Perl documentation in Pod format
146 perlhist Perl history records
147 perldelta Perl changes since previous version
148 perl594delta Perl changes in version 5.9.4
149 perl593delta Perl changes in version 5.9.3
150 perl592delta Perl changes in version 5.9.2
151 perl591delta Perl changes in version 5.9.1
152 perl590delta Perl changes in version 5.9.0
153 perl588delta Perl changes in version 5.8.8
154 perl587delta Perl changes in version 5.8.7
155 perl586delta Perl changes in version 5.8.6
156 perl585delta Perl changes in version 5.8.5
157 perl584delta Perl changes in version 5.8.4
158 perl583delta Perl changes in version 5.8.3
159 perl582delta Perl changes in version 5.8.2
160 perl581delta Perl changes in version 5.8.1
161 perl58delta Perl changes in version 5.8.0
162 perl573delta Perl changes in version 5.7.3
163 perl572delta Perl changes in version 5.7.2
164 perl571delta Perl changes in version 5.7.1
165 perl570delta Perl changes in version 5.7.0
166 perl561delta Perl changes in version 5.6.1
167 perl56delta Perl changes in version 5.6
168 perl5005delta Perl changes in version 5.005
169 perl5004delta Perl changes in version 5.004
171 perlartistic Perl Artistic License
172 perlgpl GNU General Public License
174 =head2 Language-Specific
176 perlcn Perl for Simplified Chinese (in EUC-CN)
177 perljp Perl for Japanese (in EUC-JP)
178 perlko Perl for Korean (in EUC-KR)
179 perltw Perl for Traditional Chinese (in Big5)
181 =head2 Platform-Specific
183 perlaix Perl notes for AIX
184 perlamiga Perl notes for AmigaOS
185 perlapollo Perl notes for Apollo DomainOS
186 perlbeos Perl notes for BeOS
187 perlbs2000 Perl notes for POSIX-BC BS2000
188 perlce Perl notes for WinCE
189 perlcygwin Perl notes for Cygwin
190 perldgux Perl notes for DG/UX
191 perldos Perl notes for DOS
192 perlepoc Perl notes for EPOC
193 perlfreebsd Perl notes for FreeBSD
194 perlhpux Perl notes for HP-UX
195 perlhurd Perl notes for Hurd
196 perlirix Perl notes for Irix
197 perllinux Perl notes for Linux
198 perlmachten Perl notes for Power MachTen
199 perlmacos Perl notes for Mac OS (Classic)
200 perlmacosx Perl notes for Mac OS X
201 perlmint Perl notes for MiNT
202 perlmpeix Perl notes for MPE/iX
203 perlnetware Perl notes for NetWare
204 perlopenbsd Perl notes for OpenBSD
205 perlos2 Perl notes for OS/2
206 perlos390 Perl notes for OS/390
207 perlos400 Perl notes for OS/400
208 perlplan9 Perl notes for Plan 9
209 perlqnx Perl notes for QNX
210 perlriscos Perl notes for RISC OS
211 perlsolaris Perl notes for Solaris
212 perlsymbian Perl notes for Symbian
213 perltru64 Perl notes for Tru64
214 perluts Perl notes for UTS
215 perlvmesa Perl notes for VM/ESA
216 perlvms Perl notes for VMS
217 perlvos Perl notes for Stratus VOS
218 perlwin32 Perl notes for Windows
221 By default, the manpages listed above are installed in the
222 F</usr/local/man/> directory.
224 Extensive additional documentation for Perl modules is available. The
225 default configuration for perl will place this additional documentation
226 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
227 subdirectory of the Perl library directory). Some of this additional
228 documentation is distributed standard with Perl, but you'll also find
229 documentation for third-party modules there.
231 You should be able to view Perl's documentation with your man(1)
232 program by including the proper directories in the appropriate start-up
233 files, or in the MANPATH environment variable. To find out where the
234 configuration has installed the manpages, type:
238 If the directories have a common stem, such as F</usr/local/man/man1>
239 and F</usr/local/man/man3>, you need only to add that stem
240 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
241 environment variable. If they do not share a stem, you'll have to add
244 If that doesn't work for some reason, you can still use the
245 supplied F<perldoc> script to view module information. You might
246 also look into getting a replacement man program.
248 If something strange has gone wrong with your program and you're not
249 sure where you should look for help, try the B<-w> switch first. It
250 will often point out exactly where the trouble is.
254 Perl is a language optimized for scanning arbitrary
255 text files, extracting information from those text files, and printing
256 reports based on that information. It's also a good language for many
257 system management tasks. The language is intended to be practical
258 (easy to use, efficient, complete) rather than beautiful (tiny,
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 can also deal with binary data, and can make dbm
274 files look like hashes. Setuid Perl scripts are safer than C programs
275 through a dataflow tracing mechanism that prevents many stupid
278 If you have a problem that would ordinarily use B<sed> or B<awk> or
279 B<sh>, but it exceeds their capabilities or must run a little faster,
280 and you don't want to write the silly thing in C, then Perl may be for
281 you. There are also translators to turn your B<sed> and B<awk>
282 scripts into Perl scripts.
284 But wait, there's more...
286 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
287 rewrite that provides the following additional benefits:
293 modularity and reusability using innumerable modules
295 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
299 embeddable and extensible
301 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
302 L<perlguts>, and L<xsubpp>.
306 roll-your-own magic variables (including multiple simultaneous DBM
309 Described in L<perltie> and L<AnyDBM_File>.
313 subroutines can now be overridden, autoloaded, and prototyped
315 Described in L<perlsub>.
319 arbitrarily nested data structures and anonymous functions
321 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
325 object-oriented programming
327 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
332 support for light-weight processes (threads)
334 Described in L<perlthrtut> and L<threads>.
338 support for Unicode, internationalization, and localization
340 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
346 Described in L<perlsub>.
350 regular expression enhancements
352 Described in L<perlre>, with additional examples in L<perlop>.
356 enhanced debugger and interactive Perl environment,
357 with integrated editor support
359 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
363 POSIX 1003.1 compliant library
365 Described in L<POSIX>.
369 Okay, that's I<definitely> enough hype.
373 Perl is available for most operating systems, including virtually
374 all Unix-like platforms. See L<perlport/"Supported Platforms">
383 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
385 If your Perl success stories and testimonials may be of help to others
386 who wish to advocate the use of Perl in their applications,
387 or if you wish to simply express your gratitude to Larry and the
388 Perl developers, please write to perl-thanks@perl.org .
392 "@INC" locations of perl libraries
396 a2p awk to perl translator
397 s2p sed to perl translator
399 http://www.perl.org/ the Perl homepage
400 http://www.perl.com/ Perl articles (O'Reilly)
401 http://www.cpan.org/ the Comprehensive Perl Archive
402 http://www.pm.org/ the Perl Mongers
406 The C<use warnings> pragma (and the B<-w> switch) produces some
409 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
410 diagnostics> pragma automatically turns Perl's normally terse warnings
411 and errors into these longer forms.
413 Compilation errors will tell you the line number of the error, with an
414 indication of the next token or token type that was to be examined.
415 (In a script passed to Perl via B<-e> switches, each
416 B<-e> is counted as one line.)
418 Setuid scripts have additional constraints that can produce error
419 messages such as "Insecure dependency". See L<perlsec>.
421 Did we mention that you should definitely consider using the B<-w>
426 The B<-w> switch is not mandatory.
428 Perl is at the mercy of your machine's definitions of various
429 operations such as type casting, atof(), and floating-point
430 output with sprintf().
432 If your stdio requires a seek or eof between reads and writes on a
433 particular stream, so does Perl. (This doesn't apply to sysread()
436 While none of the built-in data types have any arbitrary size limits
437 (apart from memory size), there are still a few arbitrary limits: a
438 given variable name may not be longer than 251 characters. Line numbers
439 displayed by diagnostics are internally stored as short integers,
440 so they are limited to a maximum of 65535 (higher numbers usually being
441 affected by wraparound).
443 You may mail your bug reports (be sure to include full configuration
444 information as output by the myconfig program in the perl source
445 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
446 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
447 can be used to help mail in a bug report.
449 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
450 don't tell anyone I said that.
454 The Perl motto is "There's more than one way to do it." Divining
455 how many more is left as an exercise to the reader.
457 The three principal virtues of a programmer are Laziness,
458 Impatience, and Hubris. See the Camel Book for why.