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<-A>[I<module>][=I<assertions>] ]>
13 S<[ B<-C [I<number/list>] >]>
17 S<[ B<-i>[I<extension>] ]>
18 S<[ B<-e> I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...>
20 If you're new to Perl, you should start with L<perlintro>, which is a
21 general intro for beginners and provides some background to help you
22 navigate the rest of Perl's extensive documentation.
24 For ease of access, the Perl manual has been split up into several sections.
28 perl Perl overview (this section)
29 perlintro Perl introduction for beginners
30 perltoc Perl documentation table of contents
34 perlreftut Perl references short introduction
35 perldsc Perl data structures intro
36 perllol Perl data structures: arrays of arrays
38 perlrequick Perl regular expressions quick start
39 perlretut Perl regular expressions tutorial
41 perlboot Perl OO tutorial for beginners
42 perltoot Perl OO tutorial, part 1
43 perltooc Perl OO tutorial, part 2
44 perlbot Perl OO tricks and examples
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 perlreref Perl regular expressions quick reference
81 perlref Perl references, the rest of the story
84 perltie Perl objects hidden behind simple variables
85 perldbmfilter Perl DBM filters
87 perlipc Perl interprocess communication
88 perlfork Perl fork() information
89 perlnumber Perl number semantics
91 perlthrtut Perl threads tutorial
92 perlothrtut Old Perl threads tutorial
94 perlport Perl portability guide
95 perllocale Perl locale support
96 perluniintro Perl Unicode introduction
97 perlunicode Perl Unicode support
98 perlebcdic Considerations for running Perl on EBCDIC platforms
100 perlsec Perl security
102 perlmod Perl modules: how they work
103 perlmodlib Perl modules: how to write and use
104 perlmodstyle Perl modules: how to write modules with style
105 perlmodinstall Perl modules: how to install from CPAN
106 perlnewmod Perl modules: preparing a new module for distribution
108 perlutil utilities packaged with the Perl distribution
110 perlcompile Perl compiler suite intro
112 perlfilter Perl source filters
114 perlglossary Perl Glossary
116 =head2 Internals and C Language Interface
118 perlembed Perl ways to embed perl in your C or C++ application
119 perldebguts Perl debugging guts and tips
120 perlxstut Perl XS tutorial
121 perlxs Perl XS application programming interface
122 perlclib Internal replacements for standard C library functions
123 perlguts Perl internal functions for those doing extensions
124 perlcall Perl calling conventions from C
126 perlapi Perl API listing (autogenerated)
127 perlintern Perl internal functions (autogenerated)
128 perliol C API for Perl's implementation of IO in Layers
129 perlapio Perl internal IO abstraction interface
131 perlhack Perl hackers guide
135 perlbook Perl book information
136 perltodo Perl things to do
138 perldoc Look up Perl documentation in Pod format
140 perlhist Perl history records
141 perldelta Perl changes since previous version
142 perl593delta Perl changes in version 5.9.3
143 perl592delta Perl changes in version 5.9.2
144 perl591delta Perl changes in version 5.9.1
145 perl590delta Perl changes in version 5.9.0
146 perl588delta Perl changes in version 5.8.8
147 perl587delta Perl changes in version 5.8.7
148 perl586delta Perl changes in version 5.8.6
149 perl585delta Perl changes in version 5.8.5
150 perl584delta Perl changes in version 5.8.4
151 perl583delta Perl changes in version 5.8.3
152 perl582delta Perl changes in version 5.8.2
153 perl581delta Perl changes in version 5.8.1
154 perl58delta Perl changes in version 5.8.0
155 perl573delta Perl changes in version 5.7.3
156 perl572delta Perl changes in version 5.7.2
157 perl571delta Perl changes in version 5.7.1
158 perl570delta Perl changes in version 5.7.0
159 perl561delta Perl changes in version 5.6.1
160 perl56delta Perl changes in version 5.6
161 perl5005delta Perl changes in version 5.005
162 perl5004delta Perl changes in version 5.004
164 perlartistic Perl Artistic License
165 perlgpl GNU General Public License
167 =head2 Language-Specific
169 perlcn Perl for Simplified Chinese (in EUC-CN)
170 perljp Perl for Japanese (in EUC-JP)
171 perlko Perl for Korean (in EUC-KR)
172 perltw Perl for Traditional Chinese (in Big5)
174 =head2 Platform-Specific
176 perlaix Perl notes for AIX
177 perlamiga Perl notes for AmigaOS
178 perlapollo Perl notes for Apollo DomainOS
179 perlbeos Perl notes for BeOS
180 perlbs2000 Perl notes for POSIX-BC BS2000
181 perlce Perl notes for WinCE
182 perlcygwin Perl notes for Cygwin
183 perldgux Perl notes for DG/UX
184 perldos Perl notes for DOS
185 perlepoc Perl notes for EPOC
186 perlfreebsd Perl notes for FreeBSD
187 perlhpux Perl notes for HP-UX
188 perlhurd Perl notes for Hurd
189 perlirix Perl notes for Irix
190 perllinux Perl notes for Linux
191 perlmachten Perl notes for Power MachTen
192 perlmacos Perl notes for Mac OS (Classic)
193 perlmacosx Perl notes for Mac OS X
194 perlmint Perl notes for MiNT
195 perlmpeix Perl notes for MPE/iX
196 perlnetware Perl notes for NetWare
197 perlopenbsd Perl notes for OpenBSD
198 perlos2 Perl notes for OS/2
199 perlos390 Perl notes for OS/390
200 perlos400 Perl notes for OS/400
201 perlplan9 Perl notes for Plan 9
202 perlqnx Perl notes for QNX
203 perlriscos Perl notes for RISC OS
204 perlsolaris Perl notes for Solaris
205 perlsymbian Perl notes for Symbian
206 perltru64 Perl notes for Tru64
207 perluts Perl notes for UTS
208 perlvmesa Perl notes for VM/ESA
209 perlvms Perl notes for VMS
210 perlvos Perl notes for Stratus VOS
211 perlwin32 Perl notes for Windows
214 By default, the manpages listed above are installed in the
215 F</usr/local/man/> directory.
217 Extensive additional documentation for Perl modules is available. The
218 default configuration for perl will place this additional documentation
219 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
220 subdirectory of the Perl library directory). Some of this additional
221 documentation is distributed standard with Perl, but you'll also find
222 documentation for third-party modules there.
224 You should be able to view Perl's documentation with your man(1)
225 program by including the proper directories in the appropriate start-up
226 files, or in the MANPATH environment variable. To find out where the
227 configuration has installed the manpages, type:
231 If the directories have a common stem, such as F</usr/local/man/man1>
232 and F</usr/local/man/man3>, you need only to add that stem
233 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
234 environment variable. If they do not share a stem, you'll have to add
237 If that doesn't work for some reason, you can still use the
238 supplied F<perldoc> script to view module information. You might
239 also look into getting a replacement man program.
241 If something strange has gone wrong with your program and you're not
242 sure where you should look for help, try the B<-w> switch first. It
243 will often point out exactly where the trouble is.
247 Perl is a language optimized for scanning arbitrary
248 text files, extracting information from those text files, and printing
249 reports based on that information. It's also a good language for many
250 system management tasks. The language is intended to be practical
251 (easy to use, efficient, complete) rather than beautiful (tiny,
254 Perl combines (in the author's opinion, anyway) some of the best
255 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
256 those languages should have little difficulty with it. (Language
257 historians will also note some vestiges of B<csh>, Pascal, and even
258 BASIC-PLUS.) Expression syntax corresponds closely to C
259 expression syntax. Unlike most Unix utilities, Perl does not
260 arbitrarily limit the size of your data--if you've got the memory,
261 Perl can slurp in your whole file as a single string. Recursion is of
262 unlimited depth. And the tables used by hashes (sometimes called
263 "associative arrays") grow as necessary to prevent degraded
264 performance. Perl can use sophisticated pattern matching techniques to
265 scan large amounts of data quickly. Although optimized for
266 scanning text, Perl can also deal with binary data, and can make dbm
267 files look like hashes. Setuid Perl scripts are safer than C programs
268 through a dataflow tracing mechanism that prevents many stupid
271 If you have a problem that would ordinarily use B<sed> or B<awk> or
272 B<sh>, but it exceeds their capabilities or must run a little faster,
273 and you don't want to write the silly thing in C, then Perl may be for
274 you. There are also translators to turn your B<sed> and B<awk>
275 scripts into Perl scripts.
277 But wait, there's more...
279 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
280 rewrite that provides the following additional benefits:
286 modularity and reusability using innumerable modules
288 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
292 embeddable and extensible
294 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
295 L<perlguts>, and L<xsubpp>.
299 roll-your-own magic variables (including multiple simultaneous DBM
302 Described in L<perltie> and L<AnyDBM_File>.
306 subroutines can now be overridden, autoloaded, and prototyped
308 Described in L<perlsub>.
312 arbitrarily nested data structures and anonymous functions
314 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
318 object-oriented programming
320 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
325 support for light-weight processes (threads)
327 Described in L<perlthrtut> and L<threads>.
331 support for Unicode, internationalization, and localization
333 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
339 Described in L<perlsub>.
343 regular expression enhancements
345 Described in L<perlre>, with additional examples in L<perlop>.
349 enhanced debugger and interactive Perl environment,
350 with integrated editor support
352 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
356 POSIX 1003.1 compliant library
358 Described in L<POSIX>.
362 Okay, that's I<definitely> enough hype.
366 Perl is available for most operating systems, including virtually
367 all Unix-like platforms. See L<perlport/"Supported Platforms">
376 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
378 If your Perl success stories and testimonials may be of help to others
379 who wish to advocate the use of Perl in their applications,
380 or if you wish to simply express your gratitude to Larry and the
381 Perl developers, please write to perl-thanks@perl.org .
385 "@INC" locations of perl libraries
389 a2p awk to perl translator
390 s2p sed to perl translator
392 http://www.perl.org/ the Perl homepage
393 http://www.perl.com/ Perl articles (O'Reilly)
394 http://www.cpan.org/ the Comprehensive Perl Archive
395 http://www.pm.org/ the Perl Mongers
399 The C<use warnings> pragma (and the B<-w> switch) produces some
402 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
403 diagnostics> pragma automatically turns Perl's normally terse warnings
404 and errors into these longer forms.
406 Compilation errors will tell you the line number of the error, with an
407 indication of the next token or token type that was to be examined.
408 (In a script passed to Perl via B<-e> switches, each
409 B<-e> is counted as one line.)
411 Setuid scripts have additional constraints that can produce error
412 messages such as "Insecure dependency". See L<perlsec>.
414 Did we mention that you should definitely consider using the B<-w>
419 The B<-w> switch is not mandatory.
421 Perl is at the mercy of your machine's definitions of various
422 operations such as type casting, atof(), and floating-point
423 output with sprintf().
425 If your stdio requires a seek or eof between reads and writes on a
426 particular stream, so does Perl. (This doesn't apply to sysread()
429 While none of the built-in data types have any arbitrary size limits
430 (apart from memory size), there are still a few arbitrary limits: a
431 given variable name may not be longer than 251 characters. Line numbers
432 displayed by diagnostics are internally stored as short integers,
433 so they are limited to a maximum of 65535 (higher numbers usually being
434 affected by wraparound).
436 You may mail your bug reports (be sure to include full configuration
437 information as output by the myconfig program in the perl source
438 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
439 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
440 can be used to help mail in a bug report.
442 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
443 don't tell anyone I said that.
447 The Perl motto is "There's more than one way to do it." Divining
448 how many more is left as an exercise to the reader.
450 The three principal virtues of a programmer are Laziness,
451 Impatience, and Hubris. See the Camel Book for why.