1PERL(1) Perl Programmers Reference Guide PERL(1)
2
6 perl - The Perl 5 language interpreter
7
9 perl [ -sTtuUWX ] [ -hv ] [ -V[:configvar] ]
10 [ -cw ] [ -d[t][:debugger] ] [ -D[number/list] ]
11 [ -pna ] [ -Fpattern ] [ -l[octal] ] [ -0[octal/hexadecimal] ]
12 [ -Idir ] [ -m[-]module ] [ -M[-]'module...' ] [ -f ]
13 [ -C [number/list] ] [ -S ] [ -x[dir] ]
14 [ -i[extension] ]
15 [ [-e|-E] 'command' ] [ -- ] [ programfile ] [ argument ]...
16
18 The perldoc program gives you access to all the documentation that
19 comes with Perl. You can get more documentation, tutorials and
20 community support online at <http://www.perl.org/>.
21 If you're new to Perl, you should start by running "perldoc perlintro",
23 which is a general intro for beginners and provides some background to
24 help you navigate the rest of Perl's extensive documentation. Run
25 "perldoc perldoc" to learn more things you can do with perldoc.
26 For ease of access, the Perl manual has been split up into several
28 sections.
29 Overview
31 perl Perl overview (this section)
32 perlintro Perl introduction for beginners
33 perltoc Perl documentation table of contents
34 Tutorials
36 perlreftut Perl references short introduction
37 perldsc Perl data structures intro
38 perllol Perl data structures: arrays of arrays
39 perlrequick Perl regular expressions quick start
41 perlretut Perl regular expressions tutorial
42 perlootut Perl OO tutorial for beginners
44 perlperf Perl Performance and Optimization Techniques
46 perlstyle Perl style guide
48 perlcheat Perl cheat sheet
50 perltrap Perl traps for the unwary
51 perldebtut Perl debugging tutorial
52 perlfaq Perl frequently asked questions
54 perlfaq1 General Questions About Perl
55 perlfaq2 Obtaining and Learning about Perl
56 perlfaq3 Programming Tools
57 perlfaq4 Data Manipulation
58 perlfaq5 Files and Formats
59 perlfaq6 Regexes
60 perlfaq7 Perl Language Issues
61 perlfaq8 System Interaction
62 perlfaq9 Networking
63 Reference Manual
65 perlsyn Perl syntax
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 perlpodstyle Perl POD style guide
75 perlrun Perl execution and options
76 perldiag Perl diagnostic messages
77 perllexwarn Perl warnings and their control
78 perldebug Perl debugging
79 perlvar Perl predefined variables
80 perlre Perl regular expressions, the rest of the story
81 perlrebackslash Perl regular expression backslash sequences
82 perlrecharclass Perl regular expression character classes
83 perlreref Perl regular expressions quick reference
84 perlref Perl references, the rest of the story
85 perlform Perl formats
86 perlobj Perl objects
87 perltie Perl objects hidden behind simple variables
88 perldbmfilter Perl DBM filters
89 perlipc Perl interprocess communication
91 perlfork Perl fork() information
92 perlnumber Perl number semantics
93 perlthrtut Perl threads tutorial
95 perlport Perl portability guide
97 perllocale Perl locale support
98 perluniintro Perl Unicode introduction
99 perlunicode Perl Unicode support
100 perlunifaq Perl Unicode FAQ
101 perluniprops Index of Unicode Version 6.0.0 properties in Perl
102 perlunitut Perl Unicode tutorial
103 perlebcdic Considerations for running Perl on EBCDIC platforms
104 perlsec Perl security
106 perlmod Perl modules: how they work
108 perlmodlib Perl modules: how to write and use
109 perlmodstyle Perl modules: how to write modules with style
110 perlmodinstall Perl modules: how to install from CPAN
111 perlnewmod Perl modules: preparing a new module for distribution
112 perlpragma Perl modules: writing a user pragma
113 perlutil utilities packaged with the Perl distribution
115 perlfilter Perl source filters
117 perldtrace Perl's support for DTrace
119 perlglossary Perl Glossary
121 Internals and C Language Interface
123 perlembed Perl ways to embed perl in your C or C++ application
124 perldebguts Perl debugging guts and tips
125 perlxstut Perl XS tutorial
126 perlxs Perl XS application programming interface
127 perlxstypemap Perl XS C/Perl type conversion tools
128 perlclib Internal replacements for standard C library functions
129 perlguts Perl internal functions for those doing extensions
130 perlcall Perl calling conventions from C
131 perlmroapi Perl method resolution plugin interface
132 perlreapi Perl regular expression plugin interface
133 perlreguts Perl regular expression engine internals
134 perlapi Perl API listing (autogenerated)
136 perlintern Perl internal functions (autogenerated)
137 perliol C API for Perl's implementation of IO in Layers
138 perlapio Perl internal IO abstraction interface
139 perlhack Perl hackers guide
141 perlsource Guide to the Perl source tree
142 perlinterp Overview of the Perl interpreter source and how it works
143 perlhacktut Walk through the creation of a simple C code patch
144 perlhacktips Tips for Perl core C code hacking
145 perlpolicy Perl development policies
146 perlgit Using git with the Perl repository
147 Miscellaneous
149 perlbook Perl book information
150 perlcommunity Perl community information
151 perldoc Look up Perl documentation in Pod format
153 perlhist Perl history records
155 perldelta Perl changes since previous version
156 perl5162delta Perl changes in version 5.16.2
157 perl5161delta Perl changes in version 5.16.1
158 perl5160delta Perl changes in version 5.16.0
159 perl5160delta Perl changes in version 5.16.0
160 perl5143delta Perl changes in version 5.14.3
161 perl5142delta Perl changes in version 5.14.2
162 perl5141delta Perl changes in version 5.14.1
163 perl5140delta Perl changes in version 5.14.0
164 perl5124delta Perl changes in version 5.12.4
165 perl5123delta Perl changes in version 5.12.3
166 perl5122delta Perl changes in version 5.12.2
167 perl5121delta Perl changes in version 5.12.1
168 perl5120delta Perl changes in version 5.12.0
169 perl5101delta Perl changes in version 5.10.1
170 perl5100delta Perl changes in version 5.10.0
171 perl589delta Perl changes in version 5.8.9
172 perl588delta Perl changes in version 5.8.8
173 perl587delta Perl changes in version 5.8.7
174 perl586delta Perl changes in version 5.8.6
175 perl585delta Perl changes in version 5.8.5
176 perl584delta Perl changes in version 5.8.4
177 perl583delta Perl changes in version 5.8.3
178 perl582delta Perl changes in version 5.8.2
179 perl581delta Perl changes in version 5.8.1
180 perl58delta Perl changes in version 5.8.0
181 perl561delta Perl changes in version 5.6.1
182 perl56delta Perl changes in version 5.6
183 perl5005delta Perl changes in version 5.005
184 perl5004delta Perl changes in version 5.004
185 perlexperiment A listing of experimental features in Perl
187 perlartistic Perl Artistic License
189 perlgpl GNU General Public License
190 Language-Specific
192 perlcn Perl for Simplified Chinese (in EUC-CN)
193 perljp Perl for Japanese (in EUC-JP)
194 perlko Perl for Korean (in EUC-KR)
195 perltw Perl for Traditional Chinese (in Big5)
196 Platform-Specific
198 perlaix Perl notes for AIX
199 perlamiga Perl notes for AmigaOS
200 perlbeos Perl notes for BeOS
201 perlbs2000 Perl notes for POSIX-BC BS2000
202 perlce Perl notes for WinCE
203 perlcygwin Perl notes for Cygwin
204 perldgux Perl notes for DG/UX
205 perldos Perl notes for DOS
206 perlepoc Perl notes for EPOC
207 perlfreebsd Perl notes for FreeBSD
208 perlhaiku Perl notes for Haiku
209 perlhpux Perl notes for HP-UX
210 perlhurd Perl notes for Hurd
211 perlirix Perl notes for Irix
212 perllinux Perl notes for Linux
213 perlmacos Perl notes for Mac OS (Classic)
214 perlmacosx Perl notes for Mac OS X
215 perlmpeix Perl notes for MPE/iX
216 perlnetware Perl notes for NetWare
217 perlopenbsd Perl notes for OpenBSD
218 perlos2 Perl notes for OS/2
219 perlos390 Perl notes for OS/390
220 perlos400 Perl notes for OS/400
221 perlplan9 Perl notes for Plan 9
222 perlqnx Perl notes for QNX
223 perlriscos Perl notes for RISC OS
224 perlsolaris Perl notes for Solaris
225 perlsymbian Perl notes for Symbian
226 perltru64 Perl notes for Tru64
227 perluts Perl notes for UTS
228 perlvmesa Perl notes for VM/ESA
229 perlvms Perl notes for VMS
230 perlvos Perl notes for Stratus VOS
231 perlwin32 Perl notes for Windows
232 Stubs for Deleted Documents
234 perlboot
235 perlbot
236 perltodo
237 perltooc
238 perltoot
239 On a Unix-like system, these documentation files will usually also be
241 available as manpages for use with the man program.
242 In general, if something strange has gone wrong with your program and
244 you're not sure where you should look for help, try the -w switch
245 first. It will often point out exactly where the trouble is.
246
248 Perl officially stands for Practical Extraction and Report Language,
249 except when it doesn't.
250 Perl was originally a language optimized for scanning arbitrary text
252 files, extracting information from those text files, and printing
253 reports based on that information. It quickly became a good language
254 for many system management tasks. Over the years, Perl has grown into a
255 general-purpose programming language. It's widely used for everything
256 from quick "one-liners" to full-scale application development.
257 The language is intended to be practical (easy to use, efficient,
259 complete) rather than beautiful (tiny, elegant, minimal).
260 Perl combines (in the author's opinion, anyway) some of the best
262 features of C, sed, awk, and sh, so people familiar with those
263 languages should have little difficulty with it. (Language historians
264 will also note some vestiges of csh, Pascal, and even BASIC-PLUS.)
265 Expression syntax corresponds closely to C expression syntax. Unlike
266 most Unix utilities, Perl does not arbitrarily limit the size of your
267 data--if you've got the memory, Perl can slurp in your whole file as a
268 single string. Recursion is of unlimited depth. And the tables used
269 by hashes (sometimes called "associative arrays") grow as necessary to
270 prevent degraded performance. Perl can use sophisticated pattern
271 matching techniques to scan large amounts of data quickly. Although
272 optimized for scanning text, Perl also has many excellent tools for
273 slicing and dicing binary data.
274 But wait, there's more...
276 Begun in 1993 (see perlhist), Perl version 5 is nearly a complete
278 rewrite that provides the following additional benefits:
279 · modularity and reusability using innumerable modules
281 Described in perlmod, perlmodlib, and perlmodinstall.
283 · embeddable and extensible
285 Described in perlembed, perlxstut, perlxs, perlxstypemap, perlcall,
287 perlguts, and xsubpp.
288 · roll-your-own magic variables (including multiple simultaneous DBM
290 implementations)
291 Described in perltie and AnyDBM_File.
293 · subroutines can now be overridden, autoloaded, and prototyped
295 Described in perlsub.
297 · arbitrarily nested data structures and anonymous functions
299 Described in perlreftut, perlref, perldsc, and perllol.
301 · object-oriented programming
303 Described in perlobj and perlootut.
305 · support for light-weight processes (threads)
307 Described in perlthrtut and threads.
309 · support for Unicode, internationalization, and localization
311 Described in perluniintro, perllocale and Locale::Maketext.
313 · lexical scoping
315 Described in perlsub.
317 · regular expression enhancements
319 Described in perlre, with additional examples in perlop.
321 · enhanced debugger and interactive Perl environment, with integrated
323 editor support
324 Described in perldebtut, perldebug and perldebguts.
326 · POSIX 1003.1 compliant library
328 Described in POSIX.
330 Okay, that's definitely enough hype.
332
334 Perl is available for most operating systems, including virtually all
335 Unix-like platforms. See "Supported Platforms" in perlport for a
336 listing.
337
339 See perlrun.
340
342 Larry Wall <larry@wall.org>, with the help of oodles of other folks.
343 If your Perl success stories and testimonials may be of help to others
345 who wish to advocate the use of Perl in their applications, or if you
346 wish to simply express your gratitude to Larry and the Perl developers,
347 please write to perl-thanks@perl.org .
348
350 "@INC" locations of perl libraries
351
353 http://www.perl.org/ the Perl homepage
354 http://www.perl.com/ Perl articles (O'Reilly)
355 http://www.cpan.org/ the Comprehensive Perl Archive
356 http://www.pm.org/ the Perl Mongers
357
359 The "use warnings" pragma (and the -w switch) produces some lovely
360 diagnostics.
361 See perldiag for explanations of all Perl's diagnostics. The "use
363 diagnostics" pragma automatically turns Perl's normally terse warnings
364 and errors into these longer forms.
365 Compilation errors will tell you the line number of the error, with an
367 indication of the next token or token type that was to be examined.
368 (In a script passed to Perl via -e switches, each -e is counted as one
369 line.)
370 Setuid scripts have additional constraints that can produce error
372 messages such as "Insecure dependency". See perlsec.
373 Did we mention that you should definitely consider using the -w switch?
375
377 The -w switch is not mandatory.
378 Perl is at the mercy of your machine's definitions of various
380 operations such as type casting, atof(), and floating-point output with
381 sprintf().
382 If your stdio requires a seek or eof between reads and writes on a
384 particular stream, so does Perl. (This doesn't apply to sysread() and
385 syswrite().)
386 While none of the built-in data types have any arbitrary size limits
388 (apart from memory size), there are still a few arbitrary limits: a
389 given variable name may not be longer than 251 characters. Line
390 numbers displayed by diagnostics are internally stored as short
391 integers, so they are limited to a maximum of 65535 (higher numbers
392 usually being affected by wraparound).
393 You may mail your bug reports (be sure to include full configuration
395 information as output by the myconfig program in the perl source tree,
396 or by "perl -V") to perlbug@perl.org . If you've succeeded in
397 compiling perl, the perlbug script in the utils/ subdirectory can be
398 used to help mail in a bug report.
399 Perl actually stands for Pathologically Eclectic Rubbish Lister, but
401 don't tell anyone I said that.
402
404 The Perl motto is "There's more than one way to do it." Divining how
405 many more is left as an exercise to the reader.
406 The three principal virtues of a programmer are Laziness, Impatience,
408 and Hubris. See the Camel Book for why.
409perl v5.16.3 2013-03-04 PERL(1)