3 perl - Practical Extraction and Report Language
7 B<perl> S<[ B<-sTuU> ]> S<[ B<-hv> ] [ B<-V>[:I<configvar>] ]>
8 S<[ B<-cw> ] [ B<-d>[:I<debugger>] ] [ B<-D>[I<number/list>] ]>
9 S<[ B<-pna> ] [ B<-F>I<pattern> ] [ B<-l>[I<octal>] ] [ B<-0>[I<octal>] ]>
10 S<[ B<-I>I<dir> ] [ B<-m>[B<->]I<module> ] [ B<-M>[B<->]I<'module...'> ]>
11 S<[ B<-P> ]> S<[ B<-S> ]> S<[ B<-x>[I<dir>] ]>
12 S<[ B<-i>[I<extension>] ]> S<[ B<-e> I<'command'> ]
13 [ B<--> ] [ I<programfile> ] [ I<argument> ]...>
15 If you're new to Perl, you should start with L<perlintro>, which is a
16 general intro for beginners and provides some background to help you
17 navigate the rest of Perl's extensive documentation.
19 For ease of access, the Perl manual has been split up into several sections.
23 perl Perl overview (this section)
24 perlintro Perl introduction for beginners
25 perltoc Perl documentation table of contents
29 perlreftut Perl references short introduction
30 perldsc Perl data structures intro
31 perllol Perl data structures: arrays of arrays
33 perlrequick Perl regular expressions quick start
34 perlretut Perl regular expressions tutorial
36 perlboot Perl OO tutorial for beginners
37 perltoot Perl OO tutorial, part 1
38 perltooc Perl OO tutorial, part 2
39 perlbot Perl OO tricks and examples
41 perlstyle Perl style guide
43 perlcheat Perl cheat sheet
44 perltrap Perl traps for the unwary
45 perldebtut Perl debugging tutorial
47 perlfaq Perl frequently asked questions
48 perlfaq1 General Questions About Perl
49 perlfaq2 Obtaining and Learning about Perl
50 perlfaq3 Programming Tools
51 perlfaq4 Data Manipulation
52 perlfaq5 Files and Formats
54 perlfaq7 Perl Language Issues
55 perlfaq8 System Interaction
58 =head2 Reference Manual
61 perldata Perl data structures
62 perlop Perl operators and precedence
63 perlsub Perl subroutines
64 perlfunc Perl built-in functions
65 perlopentut Perl open() tutorial
66 perlpacktut Perl pack() and unpack() tutorial
67 perlpod Perl plain old documentation
68 perlpodspec Perl plain old documentation format specification
69 perlrun Perl execution and options
70 perldiag Perl diagnostic messages
71 perllexwarn Perl warnings and their control
72 perldebug Perl debugging
73 perlvar Perl predefined variables
74 perlre Perl regular expressions, the rest of the story
75 perlreref Perl regular expressions quick reference
76 perlref Perl references, the rest of the story
79 perltie Perl objects hidden behind simple variables
80 perldbmfilter Perl DBM filters
82 perlipc Perl interprocess communication
83 perlfork Perl fork() information
84 perlnumber Perl number semantics
86 perlthrtut Perl threads tutorial
87 perlothrtut Old Perl threads tutorial
89 perlport Perl portability guide
90 perllocale Perl locale support
91 perluniintro Perl Unicode introduction
92 perlunicode Perl Unicode support
93 perlebcdic Considerations for running Perl on EBCDIC platforms
97 perlmod Perl modules: how they work
98 perlmodlib Perl modules: how to write and use
99 perlmodstyle Perl modules: how to write modules with style
100 perlmodinstall Perl modules: how to install from CPAN
101 perlnewmod Perl modules: preparing a new module for distribution
103 perlutil utilities packaged with the Perl distribution
105 perlcompile Perl compiler suite intro
107 perlfilter Perl source filters
109 =head2 Internals and C Language Interface
111 perlembed Perl ways to embed perl in your C or C++ application
112 perldebguts Perl debugging guts and tips
113 perlxstut Perl XS tutorial
114 perlxs Perl XS application programming interface
115 perlclib Internal replacements for standard C library functions
116 perlguts Perl internal functions for those doing extensions
117 perlcall Perl calling conventions from C
119 perlapi Perl API listing (autogenerated)
120 perlintern Perl internal functions (autogenerated)
121 perliol C API for Perl's implementation of IO in Layers
122 perlapio Perl internal IO abstraction interface
124 perlhack Perl hackers guide
128 perlbook Perl book information
129 perltodo Perl things to do
131 perldoc Look up Perl documentation in Pod format
133 perlhist Perl history records
134 perldelta Perl changes since previous version
135 perl591delta Perl changes in version 5.9.1
136 perl590delta Perl changes in version 5.9.0
137 perl585delta Perl changes in version 5.8.5
138 perl584delta Perl changes in version 5.8.4
139 perl583delta Perl changes in version 5.8.3
140 perl582delta Perl changes in version 5.8.2
141 perl581delta Perl changes in version 5.8.1
142 perl58delta Perl changes in version 5.8.0
143 perl573delta Perl changes in version 5.7.3
144 perl572delta Perl changes in version 5.7.2
145 perl571delta Perl changes in version 5.7.1
146 perl570delta Perl changes in version 5.7.0
147 perl561delta Perl changes in version 5.6.1
148 perl56delta Perl changes in version 5.6
149 perl5005delta Perl changes in version 5.005
150 perl5004delta Perl changes in version 5.004
152 perlartistic Perl Artistic License
153 perlgpl GNU General Public License
155 =head2 Language-Specific
157 perlcn Perl for Simplified Chinese (in EUC-CN)
158 perljp Perl for Japanese (in EUC-JP)
159 perlko Perl for Korean (in EUC-KR)
160 perltw Perl for Traditional Chinese (in Big5)
162 =head2 Platform-Specific
164 perlaix Perl notes for AIX
165 perlamiga Perl notes for AmigaOS
166 perlapollo Perl notes for Apollo DomainOS
167 perlbeos Perl notes for BeOS
168 perlbs2000 Perl notes for POSIX-BC BS2000
169 perlce Perl notes for WinCE
170 perlcygwin Perl notes for Cygwin
171 perldgux Perl notes for DG/UX
172 perldos Perl notes for DOS
173 perlepoc Perl notes for EPOC
174 perlfreebsd Perl notes for FreeBSD
175 perlhpux Perl notes for HP-UX
176 perlhurd Perl notes for Hurd
177 perlirix Perl notes for Irix
178 perlmachten Perl notes for Power MachTen
179 perlmacos Perl notes for Mac OS (Classic)
180 perlmacosx Perl notes for Mac OS X
181 perlmint Perl notes for MiNT
182 perlmpeix Perl notes for MPE/iX
183 perlnetware Perl notes for NetWare
184 perlos2 Perl notes for OS/2
185 perlos390 Perl notes for OS/390
186 perlos400 Perl notes for OS/400
187 perlplan9 Perl notes for Plan 9
188 perlqnx Perl notes for QNX
189 perlsolaris Perl notes for Solaris
190 perltru64 Perl notes for Tru64
191 perluts Perl notes for UTS
192 perlvmesa Perl notes for VM/ESA
193 perlvms Perl notes for VMS
194 perlvos Perl notes for Stratus VOS
195 perlwin32 Perl notes for Windows
198 By default, the manpages listed above are installed in the
199 F</usr/local/man/> directory.
201 Extensive additional documentation for Perl modules is available. The
202 default configuration for perl will place this additional documentation
203 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
204 subdirectory of the Perl library directory). Some of this additional
205 documentation is distributed standard with Perl, but you'll also find
206 documentation for third-party modules there.
208 You should be able to view Perl's documentation with your man(1)
209 program by including the proper directories in the appropriate start-up
210 files, or in the MANPATH environment variable. To find out where the
211 configuration has installed the manpages, type:
215 If the directories have a common stem, such as F</usr/local/man/man1>
216 and F</usr/local/man/man3>, you need only to add that stem
217 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
218 environment variable. If they do not share a stem, you'll have to add
221 If that doesn't work for some reason, you can still use the
222 supplied F<perldoc> script to view module information. You might
223 also look into getting a replacement man program.
225 If something strange has gone wrong with your program and you're not
226 sure where you should look for help, try the B<-w> switch first. It
227 will often point out exactly where the trouble is.
231 Perl is a language optimized for scanning arbitrary
232 text files, extracting information from those text files, and printing
233 reports based on that information. It's also a good language for many
234 system management tasks. The language is intended to be practical
235 (easy to use, efficient, complete) rather than beautiful (tiny,
238 Perl combines (in the author's opinion, anyway) some of the best
239 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
240 those languages should have little difficulty with it. (Language
241 historians will also note some vestiges of B<csh>, Pascal, and even
242 BASIC-PLUS.) Expression syntax corresponds closely to C
243 expression syntax. Unlike most Unix utilities, Perl does not
244 arbitrarily limit the size of your data--if you've got the memory,
245 Perl can slurp in your whole file as a single string. Recursion is of
246 unlimited depth. And the tables used by hashes (sometimes called
247 "associative arrays") grow as necessary to prevent degraded
248 performance. Perl can use sophisticated pattern matching techniques to
249 scan large amounts of data quickly. Although optimized for
250 scanning text, Perl can also deal with binary data, and can make dbm
251 files look like hashes. Setuid Perl scripts are safer than C programs
252 through a dataflow tracing mechanism that prevents many stupid
255 If you have a problem that would ordinarily use B<sed> or B<awk> or
256 B<sh>, but it exceeds their capabilities or must run a little faster,
257 and you don't want to write the silly thing in C, then Perl may be for
258 you. There are also translators to turn your B<sed> and B<awk>
259 scripts into Perl scripts.
261 But wait, there's more...
263 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
264 rewrite that provides the following additional benefits:
270 modularity and reusability using innumerable modules
272 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
276 embeddable and extensible
278 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
279 L<perlguts>, and L<xsubpp>.
283 roll-your-own magic variables (including multiple simultaneous DBM
286 Described in L<perltie> and L<AnyDBM_File>.
290 subroutines can now be overridden, autoloaded, and prototyped
292 Described in L<perlsub>.
296 arbitrarily nested data structures and anonymous functions
298 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
302 object-oriented programming
304 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
309 support for light-weight processes (threads)
311 Described in L<perlthrtut> and L<threads>.
315 support for Unicode, internationalization, and localization
317 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
323 Described in L<perlsub>.
327 regular expression enhancements
329 Described in L<perlre>, with additional examples in L<perlop>.
333 enhanced debugger and interactive Perl environment,
334 with integrated editor support
336 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
340 POSIX 1003.1 compliant library
342 Described in L<POSIX>.
346 Okay, that's I<definitely> enough hype.
350 Perl is available for most operating systems, including virtually
351 all Unix-like platforms. See L<perlport/"Supported Platforms">
360 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
362 If your Perl success stories and testimonials may be of help to others
363 who wish to advocate the use of Perl in their applications,
364 or if you wish to simply express your gratitude to Larry and the
365 Perl developers, please write to perl-thanks@perl.org .
369 "@INC" locations of perl libraries
373 a2p awk to perl translator
374 s2p sed to perl translator
376 http://www.perl.org/ the Perl Home Page
377 http://www.perl.com/ Perl articles (O'Reilly Media)
378 http://www.cpan.org/ the Comprehensive Perl Archive
382 The C<use warnings> pragma (and the B<-w> switch) produces some
385 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
386 diagnostics> pragma automatically turns Perl's normally terse warnings
387 and errors into these longer forms.
389 Compilation errors will tell you the line number of the error, with an
390 indication of the next token or token type that was to be examined.
391 (In a script passed to Perl via B<-e> switches, each
392 B<-e> is counted as one line.)
394 Setuid scripts have additional constraints that can produce error
395 messages such as "Insecure dependency". See L<perlsec>.
397 Did we mention that you should definitely consider using the B<-w>
402 The B<-w> switch is not mandatory.
404 Perl is at the mercy of your machine's definitions of various
405 operations such as type casting, atof(), and floating-point
406 output with sprintf().
408 If your stdio requires a seek or eof between reads and writes on a
409 particular stream, so does Perl. (This doesn't apply to sysread()
412 While none of the built-in data types have any arbitrary size limits
413 (apart from memory size), there are still a few arbitrary limits: a
414 given variable name may not be longer than 251 characters. Line numbers
415 displayed by diagnostics are internally stored as short integers,
416 so they are limited to a maximum of 65535 (higher numbers usually being
417 affected by wraparound).
419 You may mail your bug reports (be sure to include full configuration
420 information as output by the myconfig program in the perl source
421 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
422 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
423 can be used to help mail in a bug report.
425 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
426 don't tell anyone I said that.
430 The Perl motto is "There's more than one way to do it." Divining
431 how many more is left as an exercise to the reader.
433 The three principal virtues of a programmer are Laziness,
434 Impatience, and Hubris. See the Camel Book for why.