1=head1 NAME 2 3perl - The Perl 5 language interpreter 4 5=head1 SYNOPSIS 6 7B<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>] >]> 13 S<[ B<-S> ]> 14 S<[ B<-x>[I<dir>] ]> 15 S<[ B<-i>[I<extension>] ]> 16 S<[ [B<-e>|B<-E>] I<'command'> ] [ B<--> ] [ I<programfile> ] [ I<argument> ]...> 17 18For more information on these options, you can run C<perldoc perlrun>. 19 20=head1 GETTING HELP 21 22The F<perldoc> program gives you access to all the documentation that comes 23with Perl. You can get more documentation, tutorials and community support 24online at L<http://www.perl.org/>. 25 26If you're new to Perl, you should start by running C<perldoc perlintro>, 27which is a general intro for beginners and provides some background to help 28you navigate the rest of Perl's extensive documentation. Run C<perldoc 29perldoc> to learn more things you can do with F<perldoc>. 30 31For ease of access, the Perl manual has been split up into several sections. 32 33=begin buildtoc 34 35# This section is parsed by Porting/pod_lib.pl for use by pod/buildtoc etc 36 37flag =g perlmodlib perlapi perlintern 38flag =go perltoc 39flag =ro perlcn perljp perlko perltw 40flag = perlvms 41 42path perlfaq.* cpan/perlfaq/lib/ 43path perlglossary cpan/perlfaq/lib/ 44path perlxs(?:tut|typemap)? dist/ExtUtils-ParseXS/lib/ 45path perldoc cpan/Pod-Perldoc/ 46 47aux a2p c2ph h2ph h2xs perlbug pl2pm pod2html pod2man s2p splain xsubpp 48 49=end buildtoc 50 51=head2 Overview 52 53 perl Perl overview (this section) 54 perlintro Perl introduction for beginners 55 perlrun Perl execution and options 56 perltoc Perl documentation table of contents 57 58=head2 Tutorials 59 60 perlreftut Perl references short introduction 61 perldsc Perl data structures intro 62 perllol Perl data structures: arrays of arrays 63 64 perlrequick Perl regular expressions quick start 65 perlretut Perl regular expressions tutorial 66 67 perlootut Perl OO tutorial for beginners 68 69 perlperf Perl Performance and Optimization Techniques 70 71 perlstyle Perl style guide 72 73 perlcheat Perl cheat sheet 74 perltrap Perl traps for the unwary 75 perldebtut Perl debugging tutorial 76 77 perlfaq Perl frequently asked questions 78 perlfaq1 General Questions About Perl 79 perlfaq2 Obtaining and Learning about Perl 80 perlfaq3 Programming Tools 81 perlfaq4 Data Manipulation 82 perlfaq5 Files and Formats 83 perlfaq6 Regexes 84 perlfaq7 Perl Language Issues 85 perlfaq8 System Interaction 86 perlfaq9 Networking 87 88=head2 Reference Manual 89 90 perlsyn Perl syntax 91 perldata Perl data structures 92 perlop Perl operators and precedence 93 perlsub Perl subroutines 94 perlfunc Perl built-in functions 95 perlopentut Perl open() tutorial 96 perlpacktut Perl pack() and unpack() tutorial 97 perlpod Perl plain old documentation 98 perlpodspec Perl plain old documentation format specification 99 perlpodstyle Perl POD style guide 100 perldiag Perl diagnostic messages 101 perllexwarn Perl warnings and their control 102 perldebug Perl debugging 103 perlvar Perl predefined variables 104 perlre Perl regular expressions, the rest of the story 105 perlrebackslash Perl regular expression backslash sequences 106 perlrecharclass Perl regular expression character classes 107 perlreref Perl regular expressions quick reference 108 perlref Perl references, the rest of the story 109 perlform Perl formats 110 perlobj Perl objects 111 perltie Perl objects hidden behind simple variables 112 perldbmfilter Perl DBM filters 113 114 perlipc Perl interprocess communication 115 perlfork Perl fork() information 116 perlnumber Perl number semantics 117 118 perlthrtut Perl threads tutorial 119 120 perlport Perl portability guide 121 perllocale Perl locale support 122 perluniintro Perl Unicode introduction 123 perlunicode Perl Unicode support 124 perlunicook Perl Unicode cookbook 125 perlunifaq Perl Unicode FAQ 126 perluniprops Index of Unicode properties in Perl 127 perlunitut Perl Unicode tutorial 128 perlebcdic Considerations for running Perl on EBCDIC platforms 129 130 perlsec Perl security 131 132 perlmod Perl modules: how they work 133 perlmodlib Perl modules: how to write and use 134 perlmodstyle Perl modules: how to write modules with style 135 perlmodinstall Perl modules: how to install from CPAN 136 perlnewmod Perl modules: preparing a new module for distribution 137 perlpragma Perl modules: writing a user pragma 138 139 perlutil utilities packaged with the Perl distribution 140 141 perlfilter Perl source filters 142 143 perldtrace Perl's support for DTrace 144 145 perlglossary Perl Glossary 146 147=head2 Internals and C Language Interface 148 149 perlembed Perl ways to embed perl in your C or C++ application 150 perldebguts Perl debugging guts and tips 151 perlxstut Perl XS tutorial 152 perlxs Perl XS application programming interface 153 perlxstypemap Perl XS C/Perl type conversion tools 154 perlclib Internal replacements for standard C library functions 155 perlguts Perl internal functions for those doing extensions 156 perlcall Perl calling conventions from C 157 perlmroapi Perl method resolution plugin interface 158 perlreapi Perl regular expression plugin interface 159 perlreguts Perl regular expression engine internals 160 161 perlapi Perl API listing (autogenerated) 162 perlintern Perl internal functions (autogenerated) 163 perliol C API for Perl's implementation of IO in Layers 164 perlapio Perl internal IO abstraction interface 165 166 perlhack Perl hackers guide 167 perlsource Guide to the Perl source tree 168 perlinterp Overview of the Perl interpreter source and how it works 169 perlhacktut Walk through the creation of a simple C code patch 170 perlhacktips Tips for Perl core C code hacking 171 perlpolicy Perl development policies 172 perlgit Using git with the Perl repository 173 174=head2 Miscellaneous 175 176 perlbook Perl book information 177 perlcommunity Perl community information 178 179 perldoc Look up Perl documentation in Pod format 180 181 perlhist Perl history records 182 perldelta Perl changes since previous version 183 perl5202delta Perl changes in version 5.20.2 184 perl5201delta Perl changes in version 5.20.1 185 perl5200delta Perl changes in version 5.20.0 186 perl5184delta Perl changes in version 5.18.4 187 perl5182delta Perl changes in version 5.18.2 188 perl5181delta Perl changes in version 5.18.1 189 perl5180delta Perl changes in version 5.18.0 190 perl5163delta Perl changes in version 5.16.3 191 perl5162delta Perl changes in version 5.16.2 192 perl5161delta Perl changes in version 5.16.1 193 perl5160delta Perl changes in version 5.16.0 194 perl5144delta Perl changes in version 5.14.4 195 perl5143delta Perl changes in version 5.14.3 196 perl5142delta Perl changes in version 5.14.2 197 perl5141delta Perl changes in version 5.14.1 198 perl5140delta Perl changes in version 5.14.0 199 perl5125delta Perl changes in version 5.12.5 200 perl5124delta Perl changes in version 5.12.4 201 perl5123delta Perl changes in version 5.12.3 202 perl5122delta Perl changes in version 5.12.2 203 perl5121delta Perl changes in version 5.12.1 204 perl5120delta Perl changes in version 5.12.0 205 perl5101delta Perl changes in version 5.10.1 206 perl5100delta Perl changes in version 5.10.0 207 perl589delta Perl changes in version 5.8.9 208 perl588delta Perl changes in version 5.8.8 209 perl587delta Perl changes in version 5.8.7 210 perl586delta Perl changes in version 5.8.6 211 perl585delta Perl changes in version 5.8.5 212 perl584delta Perl changes in version 5.8.4 213 perl583delta Perl changes in version 5.8.3 214 perl582delta Perl changes in version 5.8.2 215 perl581delta Perl changes in version 5.8.1 216 perl58delta Perl changes in version 5.8.0 217 perl561delta Perl changes in version 5.6.1 218 perl56delta Perl changes in version 5.6 219 perl5005delta Perl changes in version 5.005 220 perl5004delta Perl changes in version 5.004 221 222 perlexperiment A listing of experimental features in Perl 223 224 perlartistic Perl Artistic License 225 perlgpl GNU General Public License 226 227=head2 Language-Specific 228 229=for buildtoc flag +r 230 231 perlcn Perl for Simplified Chinese (in EUC-CN) 232 perljp Perl for Japanese (in EUC-JP) 233 perlko Perl for Korean (in EUC-KR) 234 perltw Perl for Traditional Chinese (in Big5) 235 236=head2 Platform-Specific 237 238 perlaix Perl notes for AIX 239 perlamiga Perl notes for AmigaOS 240 perlandroid Perl notes for Android 241 perlbs2000 Perl notes for POSIX-BC BS2000 242 perlce Perl notes for WinCE 243 perlcygwin Perl notes for Cygwin 244 perldos Perl notes for DOS 245 perlfreebsd Perl notes for FreeBSD 246 perlhaiku Perl notes for Haiku 247 perlhpux Perl notes for HP-UX 248 perlhurd Perl notes for Hurd 249 perlirix Perl notes for Irix 250 perllinux Perl notes for Linux 251 perlmacos Perl notes for Mac OS (Classic) 252 perlmacosx Perl notes for Mac OS X 253 perlnetware Perl notes for NetWare 254 perlopenbsd Perl notes for OpenBSD 255 perlos2 Perl notes for OS/2 256 perlos390 Perl notes for OS/390 257 perlos400 Perl notes for OS/400 258 perlplan9 Perl notes for Plan 9 259 perlqnx Perl notes for QNX 260 perlriscos Perl notes for RISC OS 261 perlsolaris Perl notes for Solaris 262 perlsymbian Perl notes for Symbian 263 perlsynology Perl notes for Synology 264 perltru64 Perl notes for Tru64 265 perlvms Perl notes for VMS 266 perlvos Perl notes for Stratus VOS 267 perlwin32 Perl notes for Windows 268 269=for buildtoc flag -r 270 271=head2 Stubs for Deleted Documents 272 273 perlboot 274 perlbot 275 perlrepository 276 perltodo 277 perltooc 278 perltoot 279 280=for buildtoc __END__ 281 282On a Unix-like system, these documentation files will usually also be 283available as manpages for use with the F<man> program. 284 285Some documentation is not available as man pages, so if a 286cross-reference is not found by man, try it with L<perldoc>. Perldoc can 287also take you directly to documentation for functions (with the B<-f> 288switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>) 289for other helpful options L<perldoc> has to offer. 290 291In general, if something strange has gone wrong with your program and you're 292not sure where you should look for help, try making your code comply with 293B<use strict> and B<use warnings>. These will often point out exactly 294where the trouble is. 295 296=head1 DESCRIPTION 297 298Perl officially stands for Practical Extraction and Report Language, 299except when it doesn't. 300 301Perl was originally a language optimized for scanning arbitrary 302text files, extracting information from those text files, and printing 303reports based on that information. It quickly became a good language 304for many system management tasks. Over the years, Perl has grown into 305a general-purpose programming language. It's widely used for everything 306from quick "one-liners" to full-scale application development. 307 308The language is intended to be practical (easy to use, efficient, 309complete) rather than beautiful (tiny, elegant, minimal). It combines 310(in the author's opinion, anyway) some of the best features of B<sed>, 311B<awk>, and B<sh>, making it familiar and easy to use for Unix users to 312whip up quick solutions to annoying problems. Its general-purpose 313programming facilities support procedural, functional, and 314object-oriented programming paradigms, making Perl a comfortable 315language for the long haul on major projects, whatever your bent. 316 317Perl's roots in text processing haven't been forgotten over the years. 318It still boasts some of the most powerful regular expressions to be 319found anywhere, and its support for Unicode text is world-class. It 320handles all kinds of structured text, too, through an extensive 321collection of extensions. Those libraries, collected in the CPAN, 322provide ready-made solutions to an astounding array of problems. When 323they haven't set the standard themselves, they steal from the best 324-- just like Perl itself. 325 326=head1 AVAILABILITY 327 328Perl is available for most operating systems, including virtually 329all Unix-like platforms. See L<perlport/"Supported Platforms"> 330for a listing. 331 332=head1 ENVIRONMENT 333 334See L<perlrun>. 335 336=head1 AUTHOR 337 338Larry Wall <larry@wall.org>, with the help of oodles of other folks. 339 340If your Perl success stories and testimonials may be of help to others 341who wish to advocate the use of Perl in their applications, 342or if you wish to simply express your gratitude to Larry and the 343Perl developers, please write to perl-thanks@perl.org . 344 345=head1 FILES 346 347 "@INC" locations of perl libraries 348 349=head1 SEE ALSO 350 351 http://www.perl.org/ the Perl homepage 352 http://www.perl.com/ Perl articles (O'Reilly) 353 http://www.cpan.org/ the Comprehensive Perl Archive 354 http://www.pm.org/ the Perl Mongers 355 356=head1 DIAGNOSTICS 357 358Using the C<use strict> pragma ensures that all variables are properly 359declared and prevents other misuses of legacy Perl features. 360 361The C<use warnings> pragma produces some lovely diagnostics. One can 362also use the B<-w> flag, but its use is normally discouraged, because 363it gets applied to all executed Perl code, including that not under 364your control. 365 366See L<perldiag> for explanations of all Perl's diagnostics. The C<use 367diagnostics> pragma automatically turns Perl's normally terse warnings 368and errors into these longer forms. 369 370Compilation errors will tell you the line number of the error, with an 371indication of the next token or token type that was to be examined. 372(In a script passed to Perl via B<-e> switches, each 373B<-e> is counted as one line.) 374 375Setuid scripts have additional constraints that can produce error 376messages such as "Insecure dependency". See L<perlsec>. 377 378Did we mention that you should definitely consider using the B<use warnings> 379pragma? 380 381=head1 BUGS 382 383The behavior implied by the B<use warnings> pragma is not mandatory. 384 385Perl is at the mercy of your machine's definitions of various 386operations such as type casting, atof(), and floating-point 387output with sprintf(). 388 389If your stdio requires a seek or eof between reads and writes on a 390particular stream, so does Perl. (This doesn't apply to sysread() 391and syswrite().) 392 393While none of the built-in data types have any arbitrary size limits 394(apart from memory size), there are still a few arbitrary limits: a 395given variable name may not be longer than 251 characters. Line numbers 396displayed by diagnostics are internally stored as short integers, 397so they are limited to a maximum of 65535 (higher numbers usually being 398affected by wraparound). 399 400You may mail your bug reports (be sure to include full configuration 401information as output by the myconfig program in the perl source 402tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded 403in compiling perl, the L<perlbug> script in the F<utils/> subdirectory 404can be used to help mail in a bug report. 405 406Perl actually stands for Pathologically Eclectic Rubbish Lister, but 407don't tell anyone I said that. 408 409=head1 NOTES 410 411The Perl motto is "There's more than one way to do it." Divining 412how many more is left as an exercise to the reader. 413 414The three principal virtues of a programmer are Laziness, 415Impatience, and Hubris. See the Camel Book for why. 416 417