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<-C [I<number/list>] >]>
16 S<[ B<-i>[I<extension>] ]>
17 S<[ B<-e> I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...>
19 If you're new to Perl, you should start with L<perlintro>, which is a
20 general intro for beginners and provides some background to help you
21 navigate the rest of Perl's extensive documentation.
23 For ease of access, the Perl manual has been split up into several sections.
27 perl Perl overview (this section)
28 perlintro Perl introduction for beginners
29 perltoc Perl documentation table of contents
33 perlreftut Perl references short introduction
34 perldsc Perl data structures intro
35 perllol Perl data structures: arrays of arrays
37 perlrequick Perl regular expressions quick start
38 perlretut Perl regular expressions tutorial
40 perlboot Perl OO tutorial for beginners
41 perltoot Perl OO tutorial, part 1
42 perltooc Perl OO tutorial, part 2
43 perlbot Perl OO tricks and examples
45 perlstyle Perl style guide
47 perlcheat Perl cheat sheet
48 perltrap Perl traps for the unwary
49 perldebtut Perl debugging tutorial
51 perlfaq Perl frequently asked questions
52 perlfaq1 General Questions About Perl
53 perlfaq2 Obtaining and Learning about Perl
54 perlfaq3 Programming Tools
55 perlfaq4 Data Manipulation
56 perlfaq5 Files and Formats
58 perlfaq7 Perl Language Issues
59 perlfaq8 System Interaction
62 =head2 Reference Manual
65 perldata Perl data structures
66 perlop Perl operators and precedence
67 perlsub Perl subroutines
68 perlfunc Perl built-in functions
69 perlopentut Perl open() tutorial
70 perlpacktut Perl pack() and unpack() tutorial
71 perlpod Perl plain old documentation
72 perlpodspec Perl plain old documentation format specification
73 perlrun Perl execution and options
74 perldiag Perl diagnostic messages
75 perllexwarn Perl warnings and their control
76 perldebug Perl debugging
77 perlvar Perl predefined variables
78 perlre Perl regular expressions, the rest of the story
79 perlrebackslash Perl regular expression backslash sequences
80 perlrecharclass Perl regular expression character classes
81 perlreref Perl regular expressions quick reference
82 perlref Perl references, the rest of the story
85 perltie Perl objects hidden behind simple variables
86 perldbmfilter Perl DBM filters
88 perlipc Perl interprocess communication
89 perlfork Perl fork() information
90 perlnumber Perl number semantics
92 perlthrtut Perl threads tutorial
93 perlothrtut Old Perl threads tutorial
95 perlport Perl portability guide
96 perllocale Perl locale support
97 perluniintro Perl Unicode introduction
98 perlunicode Perl Unicode support
99 perlunifaq Perl Unicode FAQ
100 perlunitut Perl Unicode tutorial
101 perlebcdic Considerations for running Perl on EBCDIC platforms
103 perlsec Perl security
105 perlmod Perl modules: how they work
106 perlmodlib Perl modules: how to write and use
107 perlmodstyle Perl modules: how to write modules with style
108 perlmodinstall Perl modules: how to install from CPAN
109 perlnewmod Perl modules: preparing a new module for distribution
110 perlpragma Perl modules: writing a user pragma
112 perlutil utilities packaged with the Perl distribution
114 perlcompile Perl compiler suite intro
116 perlfilter Perl source filters
118 perlglossary Perl Glossary
120 =head2 Internals and C Language Interface
122 perlembed Perl ways to embed perl in your C or C++ application
123 perldebguts Perl debugging guts and tips
124 perlxstut Perl XS tutorial
125 perlxs Perl XS application programming interface
126 perlclib Internal replacements for standard C library functions
127 perlguts Perl internal functions for those doing extensions
128 perlcall Perl calling conventions from C
129 perlreapi Perl regular expression plugin interface
130 perlreguts Perl regular expression engine internals
132 perlapi Perl API listing (autogenerated)
133 perlintern Perl internal functions (autogenerated)
134 perliol C API for Perl's implementation of IO in Layers
135 perlapio Perl internal IO abstraction interface
137 perlhack Perl hackers guide
141 perlbook Perl book information
142 perlcommunity Perl community information
143 perltodo Perl things to do
145 perldoc Look up Perl documentation in Pod format
147 perlhist Perl history records
148 perldelta Perl changes since previous version
149 perl5100delta Perl changes in version 5.10.0
150 perl595delta Perl changes in version 5.9.5
151 perl594delta Perl changes in version 5.9.4
152 perl593delta Perl changes in version 5.9.3
153 perl592delta Perl changes in version 5.9.2
154 perl591delta Perl changes in version 5.9.1
155 perl590delta Perl changes in version 5.9.0
156 perl588delta Perl changes in version 5.8.8
157 perl587delta Perl changes in version 5.8.7
158 perl586delta Perl changes in version 5.8.6
159 perl585delta Perl changes in version 5.8.5
160 perl584delta Perl changes in version 5.8.4
161 perl583delta Perl changes in version 5.8.3
162 perl582delta Perl changes in version 5.8.2
163 perl581delta Perl changes in version 5.8.1
164 perl58delta Perl changes in version 5.8.0
165 perl573delta Perl changes in version 5.7.3
166 perl572delta Perl changes in version 5.7.2
167 perl571delta Perl changes in version 5.7.1
168 perl570delta Perl changes in version 5.7.0
169 perl561delta Perl changes in version 5.6.1
170 perl56delta Perl changes in version 5.6
171 perl5005delta Perl changes in version 5.005
172 perl5004delta Perl changes in version 5.004
174 perlartistic Perl Artistic License
175 perlgpl GNU General Public License
177 =head2 Language-Specific
179 perlcn Perl for Simplified Chinese (in EUC-CN)
180 perljp Perl for Japanese (in EUC-JP)
181 perlko Perl for Korean (in EUC-KR)
182 perltw Perl for Traditional Chinese (in Big5)
184 =head2 Platform-Specific
186 perlaix Perl notes for AIX
187 perlamiga Perl notes for AmigaOS
188 perlapollo Perl notes for Apollo DomainOS
189 perlbeos Perl notes for BeOS
190 perlbs2000 Perl notes for POSIX-BC BS2000
191 perlce Perl notes for WinCE
192 perlcygwin Perl notes for Cygwin
193 perldgux Perl notes for DG/UX
194 perldos Perl notes for DOS
195 perlepoc Perl notes for EPOC
196 perlfreebsd Perl notes for FreeBSD
197 perlhpux Perl notes for HP-UX
198 perlhurd Perl notes for Hurd
199 perlirix Perl notes for Irix
200 perllinux Perl notes for Linux
201 perlmachten Perl notes for Power MachTen
202 perlmacos Perl notes for Mac OS (Classic)
203 perlmacosx Perl notes for Mac OS X
204 perlmint Perl notes for MiNT
205 perlmpeix Perl notes for MPE/iX
206 perlnetware Perl notes for NetWare
207 perlopenbsd Perl notes for OpenBSD
208 perlos2 Perl notes for OS/2
209 perlos390 Perl notes for OS/390
210 perlos400 Perl notes for OS/400
211 perlplan9 Perl notes for Plan 9
212 perlqnx Perl notes for QNX
213 perlriscos Perl notes for RISC OS
214 perlsolaris Perl notes for Solaris
215 perlsymbian Perl notes for Symbian
216 perltru64 Perl notes for Tru64
217 perluts Perl notes for UTS
218 perlvmesa Perl notes for VM/ESA
219 perlvms Perl notes for VMS
220 perlvos Perl notes for Stratus VOS
221 perlwin32 Perl notes for Windows
224 By default, the manpages listed above are installed in the
225 F</usr/local/man/> directory.
227 Extensive additional documentation for Perl modules is available. The
228 default configuration for perl will place this additional documentation
229 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
230 subdirectory of the Perl library directory). Some of this additional
231 documentation is distributed standard with Perl, but you'll also find
232 documentation for third-party modules there.
234 You should be able to view Perl's documentation with your man(1)
235 program by including the proper directories in the appropriate start-up
236 files, or in the MANPATH environment variable. To find out where the
237 configuration has installed the manpages, type:
241 If the directories have a common stem, such as F</usr/local/man/man1>
242 and F</usr/local/man/man3>, you need only to add that stem
243 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
244 environment variable. If they do not share a stem, you'll have to add
247 If that doesn't work for some reason, you can still use the
248 supplied F<perldoc> script to view module information. You might
249 also look into getting a replacement man program.
251 If something strange has gone wrong with your program and you're not
252 sure where you should look for help, try the B<-w> switch first. It
253 will often point out exactly where the trouble is.
257 Perl is a language optimized for scanning arbitrary
258 text files, extracting information from those text files, and printing
259 reports based on that information. It's also a good language for many
260 system management tasks. The language is intended to be practical
261 (easy to use, efficient, complete) rather than beautiful (tiny,
264 Perl combines (in the author's opinion, anyway) some of the best
265 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
266 those languages should have little difficulty with it. (Language
267 historians will also note some vestiges of B<csh>, Pascal, and even
268 BASIC-PLUS.) Expression syntax corresponds closely to C
269 expression syntax. Unlike most Unix utilities, Perl does not
270 arbitrarily limit the size of your data--if you've got the memory,
271 Perl can slurp in your whole file as a single string. Recursion is of
272 unlimited depth. And the tables used by hashes (sometimes called
273 "associative arrays") grow as necessary to prevent degraded
274 performance. Perl can use sophisticated pattern matching techniques to
275 scan large amounts of data quickly. Although optimized for
276 scanning text, Perl can also deal with binary data, and can make dbm
277 files look like hashes. Setuid Perl scripts are safer than C programs
278 through a dataflow tracing mechanism that prevents many stupid
281 If you have a problem that would ordinarily use B<sed> or B<awk> or
282 B<sh>, but it exceeds their capabilities or must run a little faster,
283 and you don't want to write the silly thing in C, then Perl may be for
284 you. There are also translators to turn your B<sed> and B<awk>
285 scripts into Perl scripts.
287 But wait, there's more...
289 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
290 rewrite that provides the following additional benefits:
296 modularity and reusability using innumerable modules
298 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
302 embeddable and extensible
304 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
305 L<perlguts>, and L<xsubpp>.
309 roll-your-own magic variables (including multiple simultaneous DBM
312 Described in L<perltie> and L<AnyDBM_File>.
316 subroutines can now be overridden, autoloaded, and prototyped
318 Described in L<perlsub>.
322 arbitrarily nested data structures and anonymous functions
324 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
328 object-oriented programming
330 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
335 support for light-weight processes (threads)
337 Described in L<perlthrtut> and L<threads>.
341 support for Unicode, internationalization, and localization
343 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
349 Described in L<perlsub>.
353 regular expression enhancements
355 Described in L<perlre>, with additional examples in L<perlop>.
359 enhanced debugger and interactive Perl environment,
360 with integrated editor support
362 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
366 POSIX 1003.1 compliant library
368 Described in L<POSIX>.
372 Okay, that's I<definitely> enough hype.
376 Perl is available for most operating systems, including virtually
377 all Unix-like platforms. See L<perlport/"Supported Platforms">
386 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
388 If your Perl success stories and testimonials may be of help to others
389 who wish to advocate the use of Perl in their applications,
390 or if you wish to simply express your gratitude to Larry and the
391 Perl developers, please write to perl-thanks@perl.org .
395 "@INC" locations of perl libraries
399 a2p awk to perl translator
400 s2p sed to perl translator
402 http://www.perl.org/ the Perl homepage
403 http://www.perl.com/ Perl articles (O'Reilly)
404 http://www.cpan.org/ the Comprehensive Perl Archive
405 http://www.pm.org/ the Perl Mongers
409 The C<use warnings> pragma (and the B<-w> switch) produces some
412 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
413 diagnostics> pragma automatically turns Perl's normally terse warnings
414 and errors into these longer forms.
416 Compilation errors will tell you the line number of the error, with an
417 indication of the next token or token type that was to be examined.
418 (In a script passed to Perl via B<-e> switches, each
419 B<-e> is counted as one line.)
421 Setuid scripts have additional constraints that can produce error
422 messages such as "Insecure dependency". See L<perlsec>.
424 Did we mention that you should definitely consider using the B<-w>
429 The B<-w> switch is not mandatory.
431 Perl is at the mercy of your machine's definitions of various
432 operations such as type casting, atof(), and floating-point
433 output with sprintf().
435 If your stdio requires a seek or eof between reads and writes on a
436 particular stream, so does Perl. (This doesn't apply to sysread()
439 While none of the built-in data types have any arbitrary size limits
440 (apart from memory size), there are still a few arbitrary limits: a
441 given variable name may not be longer than 251 characters. Line numbers
442 displayed by diagnostics are internally stored as short integers,
443 so they are limited to a maximum of 65535 (higher numbers usually being
444 affected by wraparound).
446 You may mail your bug reports (be sure to include full configuration
447 information as output by the myconfig program in the perl source
448 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
449 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
450 can be used to help mail in a bug report.
452 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
453 don't tell anyone I said that.
457 The Perl motto is "There's more than one way to do it." Divining
458 how many more is left as an exercise to the reader.
460 The three principal virtues of a programmer are Laziness,
461 Impatience, and Hubris. See the Camel Book for why.