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