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