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 perl594delta Perl changes in version 5.9.4
150 perl593delta Perl changes in version 5.9.3
151 perl592delta Perl changes in version 5.9.2
152 perl591delta Perl changes in version 5.9.1
153 perl590delta Perl changes in version 5.9.0
154 perl588delta Perl changes in version 5.8.8
155 perl587delta Perl changes in version 5.8.7
156 perl586delta Perl changes in version 5.8.6
157 perl585delta Perl changes in version 5.8.5
158 perl584delta Perl changes in version 5.8.4
159 perl583delta Perl changes in version 5.8.3
160 perl582delta Perl changes in version 5.8.2
161 perl581delta Perl changes in version 5.8.1
162 perl58delta Perl changes in version 5.8.0
163 perl573delta Perl changes in version 5.7.3
164 perl572delta Perl changes in version 5.7.2
165 perl571delta Perl changes in version 5.7.1
166 perl570delta Perl changes in version 5.7.0
167 perl561delta Perl changes in version 5.6.1
168 perl56delta Perl changes in version 5.6
169 perl5005delta Perl changes in version 5.005
170 perl5004delta Perl changes in version 5.004
172 perlartistic Perl Artistic License
173 perlgpl GNU General Public License
175 =head2 Language-Specific
177 perlcn Perl for Simplified Chinese (in EUC-CN)
178 perljp Perl for Japanese (in EUC-JP)
179 perlko Perl for Korean (in EUC-KR)
180 perltw Perl for Traditional Chinese (in Big5)
182 =head2 Platform-Specific
184 perlaix Perl notes for AIX
185 perlamiga Perl notes for AmigaOS
186 perlapollo Perl notes for Apollo DomainOS
187 perlbeos Perl notes for BeOS
188 perlbs2000 Perl notes for POSIX-BC BS2000
189 perlce Perl notes for WinCE
190 perlcygwin Perl notes for Cygwin
191 perldgux Perl notes for DG/UX
192 perldos Perl notes for DOS
193 perlepoc Perl notes for EPOC
194 perlfreebsd Perl notes for FreeBSD
195 perlhpux Perl notes for HP-UX
196 perlhurd Perl notes for Hurd
197 perlirix Perl notes for Irix
198 perllinux Perl notes for Linux
199 perlmachten Perl notes for Power MachTen
200 perlmacos Perl notes for Mac OS (Classic)
201 perlmacosx Perl notes for Mac OS X
202 perlmint Perl notes for MiNT
203 perlmpeix Perl notes for MPE/iX
204 perlnetware Perl notes for NetWare
205 perlopenbsd Perl notes for OpenBSD
206 perlos2 Perl notes for OS/2
207 perlos390 Perl notes for OS/390
208 perlos400 Perl notes for OS/400
209 perlplan9 Perl notes for Plan 9
210 perlqnx Perl notes for QNX
211 perlriscos Perl notes for RISC OS
212 perlsolaris Perl notes for Solaris
213 perlsymbian Perl notes for Symbian
214 perltru64 Perl notes for Tru64
215 perluts Perl notes for UTS
216 perlvmesa Perl notes for VM/ESA
217 perlvms Perl notes for VMS
218 perlvos Perl notes for Stratus VOS
219 perlwin32 Perl notes for Windows
222 By default, the manpages listed above are installed in the
223 F</usr/local/man/> directory.
225 Extensive additional documentation for Perl modules is available. The
226 default configuration for perl will place this additional documentation
227 in the F</usr/local/lib/perl5/man> directory (or else in the F<man>
228 subdirectory of the Perl library directory). Some of this additional
229 documentation is distributed standard with Perl, but you'll also find
230 documentation for third-party modules there.
232 You should be able to view Perl's documentation with your man(1)
233 program by including the proper directories in the appropriate start-up
234 files, or in the MANPATH environment variable. To find out where the
235 configuration has installed the manpages, type:
239 If the directories have a common stem, such as F</usr/local/man/man1>
240 and F</usr/local/man/man3>, you need only to add that stem
241 (F</usr/local/man>) to your man(1) configuration files or your MANPATH
242 environment variable. If they do not share a stem, you'll have to add
245 If that doesn't work for some reason, you can still use the
246 supplied F<perldoc> script to view module information. You might
247 also look into getting a replacement man program.
249 If something strange has gone wrong with your program and you're not
250 sure where you should look for help, try the B<-w> switch first. It
251 will often point out exactly where the trouble is.
255 Perl is a language optimized for scanning arbitrary
256 text files, extracting information from those text files, and printing
257 reports based on that information. It's also a good language for many
258 system management tasks. The language is intended to be practical
259 (easy to use, efficient, complete) rather than beautiful (tiny,
262 Perl combines (in the author's opinion, anyway) some of the best
263 features of C, B<sed>, B<awk>, and B<sh>, so people familiar with
264 those languages should have little difficulty with it. (Language
265 historians will also note some vestiges of B<csh>, Pascal, and even
266 BASIC-PLUS.) Expression syntax corresponds closely to C
267 expression syntax. Unlike most Unix utilities, Perl does not
268 arbitrarily limit the size of your data--if you've got the memory,
269 Perl can slurp in your whole file as a single string. Recursion is of
270 unlimited depth. And the tables used by hashes (sometimes called
271 "associative arrays") grow as necessary to prevent degraded
272 performance. Perl can use sophisticated pattern matching techniques to
273 scan large amounts of data quickly. Although optimized for
274 scanning text, Perl can also deal with binary data, and can make dbm
275 files look like hashes. Setuid Perl scripts are safer than C programs
276 through a dataflow tracing mechanism that prevents many stupid
279 If you have a problem that would ordinarily use B<sed> or B<awk> or
280 B<sh>, but it exceeds their capabilities or must run a little faster,
281 and you don't want to write the silly thing in C, then Perl may be for
282 you. There are also translators to turn your B<sed> and B<awk>
283 scripts into Perl scripts.
285 But wait, there's more...
287 Begun in 1993 (see L<perlhist>), Perl version 5 is nearly a complete
288 rewrite that provides the following additional benefits:
294 modularity and reusability using innumerable modules
296 Described in L<perlmod>, L<perlmodlib>, and L<perlmodinstall>.
300 embeddable and extensible
302 Described in L<perlembed>, L<perlxstut>, L<perlxs>, L<perlcall>,
303 L<perlguts>, and L<xsubpp>.
307 roll-your-own magic variables (including multiple simultaneous DBM
310 Described in L<perltie> and L<AnyDBM_File>.
314 subroutines can now be overridden, autoloaded, and prototyped
316 Described in L<perlsub>.
320 arbitrarily nested data structures and anonymous functions
322 Described in L<perlreftut>, L<perlref>, L<perldsc>, and L<perllol>.
326 object-oriented programming
328 Described in L<perlobj>, L<perlboot>, L<perltoot>, L<perltooc>,
333 support for light-weight processes (threads)
335 Described in L<perlthrtut> and L<threads>.
339 support for Unicode, internationalization, and localization
341 Described in L<perluniintro>, L<perllocale> and L<Locale::Maketext>.
347 Described in L<perlsub>.
351 regular expression enhancements
353 Described in L<perlre>, with additional examples in L<perlop>.
357 enhanced debugger and interactive Perl environment,
358 with integrated editor support
360 Described in L<perldebtut>, L<perldebug> and L<perldebguts>.
364 POSIX 1003.1 compliant library
366 Described in L<POSIX>.
370 Okay, that's I<definitely> enough hype.
374 Perl is available for most operating systems, including virtually
375 all Unix-like platforms. See L<perlport/"Supported Platforms">
384 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
386 If your Perl success stories and testimonials may be of help to others
387 who wish to advocate the use of Perl in their applications,
388 or if you wish to simply express your gratitude to Larry and the
389 Perl developers, please write to perl-thanks@perl.org .
393 "@INC" locations of perl libraries
397 a2p awk to perl translator
398 s2p sed to perl translator
400 http://www.perl.org/ the Perl homepage
401 http://www.perl.com/ Perl articles (O'Reilly)
402 http://www.cpan.org/ the Comprehensive Perl Archive
403 http://www.pm.org/ the Perl Mongers
407 The C<use warnings> pragma (and the B<-w> switch) produces some
410 See L<perldiag> for explanations of all Perl's diagnostics. The C<use
411 diagnostics> pragma automatically turns Perl's normally terse warnings
412 and errors into these longer forms.
414 Compilation errors will tell you the line number of the error, with an
415 indication of the next token or token type that was to be examined.
416 (In a script passed to Perl via B<-e> switches, each
417 B<-e> is counted as one line.)
419 Setuid scripts have additional constraints that can produce error
420 messages such as "Insecure dependency". See L<perlsec>.
422 Did we mention that you should definitely consider using the B<-w>
427 The B<-w> switch is not mandatory.
429 Perl is at the mercy of your machine's definitions of various
430 operations such as type casting, atof(), and floating-point
431 output with sprintf().
433 If your stdio requires a seek or eof between reads and writes on a
434 particular stream, so does Perl. (This doesn't apply to sysread()
437 While none of the built-in data types have any arbitrary size limits
438 (apart from memory size), there are still a few arbitrary limits: a
439 given variable name may not be longer than 251 characters. Line numbers
440 displayed by diagnostics are internally stored as short integers,
441 so they are limited to a maximum of 65535 (higher numbers usually being
442 affected by wraparound).
444 You may mail your bug reports (be sure to include full configuration
445 information as output by the myconfig program in the perl source
446 tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded
447 in compiling perl, the B<perlbug> script in the F<utils/> subdirectory
448 can be used to help mail in a bug report.
450 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
451 don't tell anyone I said that.
455 The Perl motto is "There's more than one way to do it." Divining
456 how many more is left as an exercise to the reader.
458 The three principal virtues of a programmer are Laziness,
459 Impatience, and Hubris. See the Camel Book for why.