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
107 perlpragma Perl modules: writing a user pragma
109 perlutil utilities packaged with the Perl distribution
111 perlcompile Perl compiler suite intro
113 perlfilter Perl source filters
115 perlglossary Perl Glossary
117 =head2 Internals and C Language Interface
119 perlembed Perl ways to embed perl in your C or C++ application
120 perldebguts Perl debugging guts and tips
121 perlxstut Perl XS tutorial
122 perlxs Perl XS application programming interface
123 perlclib Internal replacements for standard C library functions
124 perlguts Perl internal functions for those doing extensions
125 perlcall Perl calling conventions from C
127 perlapi Perl API listing (autogenerated)
128 perlintern Perl internal functions (autogenerated)
129 perliol C API for Perl's implementation of IO in Layers
130 perlapio Perl internal IO abstraction interface
132 perlhack Perl hackers guide
136 perlbook Perl book information
137 perltodo Perl things to do
139 perldoc Look up Perl documentation in Pod format
141 perlhist Perl history records
142 perldelta Perl changes since previous version
143 perl593delta Perl changes in version 5.9.3
144 perl592delta Perl changes in version 5.9.2
145 perl591delta Perl changes in version 5.9.1
146 perl590delta Perl changes in version 5.9.0
147 perl588delta Perl changes in version 5.8.8
148 perl587delta Perl changes in version 5.8.7
149 perl586delta Perl changes in version 5.8.6
150 perl585delta Perl changes in version 5.8.5
151 perl584delta Perl changes in version 5.8.4
152 perl583delta Perl changes in version 5.8.3
153 perl582delta Perl changes in version 5.8.2
154 perl581delta Perl changes in version 5.8.1
155 perl58delta Perl changes in version 5.8.0
156 perl573delta Perl changes in version 5.7.3
157 perl572delta Perl changes in version 5.7.2
158 perl571delta Perl changes in version 5.7.1
159 perl570delta Perl changes in version 5.7.0
160 perl561delta Perl changes in version 5.6.1
161 perl56delta Perl changes in version 5.6
162 perl5005delta Perl changes in version 5.005
163 perl5004delta Perl changes in version 5.004
165 perlartistic Perl Artistic License
166 perlgpl GNU General Public License
168 =head2 Language-Specific
170 perlcn Perl for Simplified Chinese (in EUC-CN)
171 perljp Perl for Japanese (in EUC-JP)
172 perlko Perl for Korean (in EUC-KR)
173 perltw Perl for Traditional Chinese (in Big5)
175 =head2 Platform-Specific
177 perlaix Perl notes for AIX
178 perlamiga Perl notes for AmigaOS
179 perlapollo Perl notes for Apollo DomainOS
180 perlbeos Perl notes for BeOS
181 perlbs2000 Perl notes for POSIX-BC BS2000
182 perlce Perl notes for WinCE
183 perlcygwin Perl notes for Cygwin
184 perldgux Perl notes for DG/UX
185 perldos Perl notes for DOS
186 perlepoc Perl notes for EPOC
187 perlfreebsd Perl notes for FreeBSD
188 perlhpux Perl notes for HP-UX
189 perlhurd Perl notes for Hurd
190 perlirix Perl notes for Irix
191 perllinux Perl notes for Linux
192 perlmachten Perl notes for Power MachTen
193 perlmacos Perl notes for Mac OS (Classic)
194 perlmacosx Perl notes for Mac OS X
195 perlmint Perl notes for MiNT
196 perlmpeix Perl notes for MPE/iX
197 perlnetware Perl notes for NetWare
198 perlopenbsd Perl notes for OpenBSD
199 perlos2 Perl notes for OS/2
200 perlos390 Perl notes for OS/390
201 perlos400 Perl notes for OS/400
202 perlplan9 Perl notes for Plan 9
203 perlqnx Perl notes for QNX
204 perlriscos Perl notes for RISC OS
205 perlsolaris Perl notes for Solaris
206 perlsymbian Perl notes for Symbian
207 perltru64 Perl notes for Tru64
208 perluts Perl notes for UTS
209 perlvmesa Perl notes for VM/ESA
210 perlvms Perl notes for VMS
211 perlvos Perl notes for Stratus VOS
212 perlwin32 Perl notes for Windows
215 By default, the manpages listed above are installed in the
216 F</usr/local/man/> directory.
218 Extensive additional documentation for Perl modules is available. The
219 default configuration for perl will place this additional documentation
220 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
221 subdirectory of the Perl library directory). Some of this additional
222 documentation is distributed standard with Perl, but you'll also find
223 documentation for third-party modules there.
225 You should be able to view Perl's documentation with your man(1)
226 program by including the proper directories in the appropriate start-up
227 files, or in the MANPATH environment variable. To find out where the
228 configuration has installed the manpages, type:
232 If the directories have a common stem, such as F</usr/local/man/man1>
233 and F</usr/local/man/man3>, you need only to add that stem
234 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
235 environment variable. If they do not share a stem, you'll have to add
238 If that doesn't work for some reason, you can still use the
239 supplied F<perldoc> script to view module information. You might
240 also look into getting a replacement man program.
242 If something strange has gone wrong with your program and you're not
243 sure where you should look for help, try the B<-w> switch first. It
244 will often point out exactly where the trouble is.
248 Perl is a language optimized for scanning arbitrary
249 text files, extracting information from those text files, and printing
250 reports based on that information. It's also a good language for many
251 system management tasks. The language is intended to be practical
252 (easy to use, efficient, complete) rather than beautiful (tiny,
255 Perl combines (in the author's opinion, anyway) some of the best
256 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
257 those languages should have little difficulty with it. (Language
258 historians will also note some vestiges of B<csh>, Pascal, and even
259 BASIC-PLUS.) Expression syntax corresponds closely to C
260 expression syntax. Unlike most Unix utilities, Perl does not
261 arbitrarily limit the size of your data--if you've got the memory,
262 Perl can slurp in your whole file as a single string. Recursion is of
263 unlimited depth. And the tables used by hashes (sometimes called
264 "associative arrays") grow as necessary to prevent degraded
265 performance. Perl can use sophisticated pattern matching techniques to
266 scan large amounts of data quickly. Although optimized for
267 scanning text, Perl can also deal with binary data, and can make dbm
268 files look like hashes. Setuid Perl scripts are safer than C programs
269 through a dataflow tracing mechanism that prevents many stupid
272 If you have a problem that would ordinarily use B<sed> or B<awk> or
273 B<sh>, but it exceeds their capabilities or must run a little faster,
274 and you don't want to write the silly thing in C, then Perl may be for
275 you. There are also translators to turn your B<sed> and B<awk>
276 scripts into Perl scripts.
278 But wait, there's more...
280 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
281 rewrite that provides the following additional benefits:
287 modularity and reusability using innumerable modules
289 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
293 embeddable and extensible
295 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
296 L<perlguts>, and L<xsubpp>.
300 roll-your-own magic variables (including multiple simultaneous DBM
303 Described in L<perltie> and L<AnyDBM_File>.
307 subroutines can now be overridden, autoloaded, and prototyped
309 Described in L<perlsub>.
313 arbitrarily nested data structures and anonymous functions
315 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
319 object-oriented programming
321 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
326 support for light-weight processes (threads)
328 Described in L<perlthrtut> and L<threads>.
332 support for Unicode, internationalization, and localization
334 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
340 Described in L<perlsub>.
344 regular expression enhancements
346 Described in L<perlre>, with additional examples in L<perlop>.
350 enhanced debugger and interactive Perl environment,
351 with integrated editor support
353 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
357 POSIX 1003.1 compliant library
359 Described in L<POSIX>.
363 Okay, that's I<definitely> enough hype.
367 Perl is available for most operating systems, including virtually
368 all Unix-like platforms. See L<perlport/"Supported Platforms">
377 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
379 If your Perl success stories and testimonials may be of help to others
380 who wish to advocate the use of Perl in their applications,
381 or if you wish to simply express your gratitude to Larry and the
382 Perl developers, please write to perl-thanks@perl.org .
386 "@INC" locations of perl libraries
390 a2p awk to perl translator
391 s2p sed to perl translator
393 http://www.perl.org/ the Perl homepage
394 http://www.perl.com/ Perl articles (O'Reilly)
395 http://www.cpan.org/ the Comprehensive Perl Archive
396 http://www.pm.org/ the Perl Mongers
400 The C<use warnings> pragma (and the B<-w> switch) produces some
403 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
404 diagnostics> pragma automatically turns Perl's normally terse warnings
405 and errors into these longer forms.
407 Compilation errors will tell you the line number of the error, with an
408 indication of the next token or token type that was to be examined.
409 (In a script passed to Perl via B<-e> switches, each
410 B<-e> is counted as one line.)
412 Setuid scripts have additional constraints that can produce error
413 messages such as "Insecure dependency". See L<perlsec>.
415 Did we mention that you should definitely consider using the B<-w>
420 The B<-w> switch is not mandatory.
422 Perl is at the mercy of your machine's definitions of various
423 operations such as type casting, atof(), and floating-point
424 output with sprintf().
426 If your stdio requires a seek or eof between reads and writes on a
427 particular stream, so does Perl. (This doesn't apply to sysread()
430 While none of the built-in data types have any arbitrary size limits
431 (apart from memory size), there are still a few arbitrary limits: a
432 given variable name may not be longer than 251 characters. Line numbers
433 displayed by diagnostics are internally stored as short integers,
434 so they are limited to a maximum of 65535 (higher numbers usually being
435 affected by wraparound).
437 You may mail your bug reports (be sure to include full configuration
438 information as output by the myconfig program in the perl source
439 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
440 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
441 can be used to help mail in a bug report.
443 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
444 don't tell anyone I said that.
448 The Perl motto is "There's more than one way to do it." Divining
449 how many more is left as an exercise to the reader.
451 The three principal virtues of a programmer are Laziness,
452 Impatience, and Hubris. See the Camel Book for why.