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/lib/ 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 perlunifaq Perl Unicode FAQ 125 perluniprops Index of Unicode properties in Perl 126 perlunitut Perl Unicode tutorial 127 perlebcdic Considerations for running Perl on EBCDIC platforms 128 129 perlsec Perl security 130 131 perlmod Perl modules: how they work 132 perlmodlib Perl modules: how to write and use 133 perlmodstyle Perl modules: how to write modules with style 134 perlmodinstall Perl modules: how to install from CPAN 135 perlnewmod Perl modules: preparing a new module for distribution 136 perlpragma Perl modules: writing a user pragma 137 138 perlutil utilities packaged with the Perl distribution 139 140 perlfilter Perl source filters 141 142 perldtrace Perl's support for DTrace 143 144 perlglossary Perl Glossary 145 146=head2 Internals and C Language Interface 147 148 perlembed Perl ways to embed perl in your C or C++ application 149 perldebguts Perl debugging guts and tips 150 perlxstut Perl XS tutorial 151 perlxs Perl XS application programming interface 152 perlxstypemap Perl XS C/Perl type conversion tools 153 perlclib Internal replacements for standard C library functions 154 perlguts Perl internal functions for those doing extensions 155 perlcall Perl calling conventions from C 156 perlmroapi Perl method resolution plugin interface 157 perlreapi Perl regular expression plugin interface 158 perlreguts Perl regular expression engine internals 159 160 perlapi Perl API listing (autogenerated) 161 perlintern Perl internal functions (autogenerated) 162 perliol C API for Perl's implementation of IO in Layers 163 perlapio Perl internal IO abstraction interface 164 165 perlhack Perl hackers guide 166 perlsource Guide to the Perl source tree 167 perlinterp Overview of the Perl interpreter source and how it works 168 perlhacktut Walk through the creation of a simple C code patch 169 perlhacktips Tips for Perl core C code hacking 170 perlpolicy Perl development policies 171 perlgit Using git with the Perl repository 172 173=head2 Miscellaneous 174 175 perlbook Perl book information 176 perlcommunity Perl community information 177 178 perldoc Look up Perl documentation in Pod format 179 180 perlhist Perl history records 181 perldelta Perl changes since previous version 182 perl5181delta Perl changes in version 5.18.1 183 perl5180delta Perl changes in version 5.18.0 184 perl5161delta Perl changes in version 5.16.1 185 perl5162delta Perl changes in version 5.16.2 186 perl5163delta Perl changes in version 5.16.3 187 perl5160delta Perl changes in version 5.16.0 188 perl5144delta Perl changes in version 5.14.4 189 perl5143delta Perl changes in version 5.14.3 190 perl5142delta Perl changes in version 5.14.2 191 perl5141delta Perl changes in version 5.14.1 192 perl5140delta Perl changes in version 5.14.0 193 perl5125delta Perl changes in version 5.12.5 194 perl5124delta Perl changes in version 5.12.4 195 perl5123delta Perl changes in version 5.12.3 196 perl5122delta Perl changes in version 5.12.2 197 perl5121delta Perl changes in version 5.12.1 198 perl5120delta Perl changes in version 5.12.0 199 perl5101delta Perl changes in version 5.10.1 200 perl5100delta Perl changes in version 5.10.0 201 perl589delta Perl changes in version 5.8.9 202 perl588delta Perl changes in version 5.8.8 203 perl587delta Perl changes in version 5.8.7 204 perl586delta Perl changes in version 5.8.6 205 perl585delta Perl changes in version 5.8.5 206 perl584delta Perl changes in version 5.8.4 207 perl583delta Perl changes in version 5.8.3 208 perl582delta Perl changes in version 5.8.2 209 perl581delta Perl changes in version 5.8.1 210 perl58delta Perl changes in version 5.8.0 211 perl561delta Perl changes in version 5.6.1 212 perl56delta Perl changes in version 5.6 213 perl5005delta Perl changes in version 5.005 214 perl5004delta Perl changes in version 5.004 215 216 perlexperiment A listing of experimental features in Perl 217 218 perlartistic Perl Artistic License 219 perlgpl GNU General Public License 220 221=head2 Language-Specific 222 223=for buildtoc flag +r 224 225 perlcn Perl for Simplified Chinese (in EUC-CN) 226 perljp Perl for Japanese (in EUC-JP) 227 perlko Perl for Korean (in EUC-KR) 228 perltw Perl for Traditional Chinese (in Big5) 229 230=head2 Platform-Specific 231 232 perlaix Perl notes for AIX 233 perlamiga Perl notes for AmigaOS 234 perlbs2000 Perl notes for POSIX-BC BS2000 235 perlce Perl notes for WinCE 236 perlcygwin Perl notes for Cygwin 237 perldgux Perl notes for DG/UX 238 perldos Perl notes for DOS 239 perlfreebsd Perl notes for FreeBSD 240 perlhaiku Perl notes for Haiku 241 perlhpux Perl notes for HP-UX 242 perlhurd Perl notes for Hurd 243 perlirix Perl notes for Irix 244 perllinux Perl notes for Linux 245 perlmacos Perl notes for Mac OS (Classic) 246 perlmacosx Perl notes for Mac OS X 247 perlnetware Perl notes for NetWare 248 perlopenbsd Perl notes for OpenBSD 249 perlos2 Perl notes for OS/2 250 perlos390 Perl notes for OS/390 251 perlos400 Perl notes for OS/400 252 perlplan9 Perl notes for Plan 9 253 perlqnx Perl notes for QNX 254 perlriscos Perl notes for RISC OS 255 perlsolaris Perl notes for Solaris 256 perlsymbian Perl notes for Symbian 257 perltru64 Perl notes for Tru64 258 perlvms Perl notes for VMS 259 perlvos Perl notes for Stratus VOS 260 perlwin32 Perl notes for Windows 261 262=for buildtoc flag -r 263 264=head2 Stubs for Deleted Documents 265 266 perlboot 267 perlbot 268 perltodo 269 perltooc 270 perltoot 271 perlrepository 272 273=for buildtoc __END__ 274 275On a Unix-like system, these documentation files will usually also be 276available as manpages for use with the F<man> program. 277 278Some documentation is not available as man pages, so if a 279cross-reference is not found by man, try it with L<perldoc>. Perldoc can 280also take you directly to documentation for functions (with the B<-f> 281switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>) 282for other helpful options L<perldoc> has to offer. 283 284In general, if something strange has gone wrong with your program and you're 285not sure where you should look for help, try making your code comply with 286B<use strict> and B<use warnings>. These will often point out exactly 287where the trouble is. 288 289=head1 DESCRIPTION 290 291Perl officially stands for Practical Extraction and Report Language, 292except when it doesn't. 293 294Perl was originally a language optimized for scanning arbitrary 295text files, extracting information from those text files, and printing 296reports based on that information. It quickly became a good language 297for many system management tasks. Over the years, Perl has grown into 298a general-purpose programming language. It's widely used for everything 299from quick "one-liners" to full-scale application development. 300 301The language is intended to be practical (easy to use, efficient, 302complete) rather than beautiful (tiny, elegant, minimal). It combines 303(in the author's opinion, anyway) some of the best features of B<sed>, 304B<awk>, and B<sh>, making it familiar and easy to use for Unix users to 305whip up quick solutions to annoying problems. Its general-purpose 306programming facilities support procedural, functional, and 307object-oriented programming paradigms, making Perl a comfortable 308language for the long haul on major projects, whatever your bent. 309 310Perl's roots in text processing haven't been forgotten over the years. 311It still boasts some of the most powerful regular expressions to be 312found anywhere, and its support for Unicode text is world-class. It 313handles all kinds of structured text, too, through an extensive 314collection of extensions. Those libraries, collected in the CPAN, 315provide ready-made solutions to an astounding array of problems. When 316they haven't set the standard themselves, they steal from the best 317-- just like Perl itself. 318 319=head1 AVAILABILITY 320 321Perl is available for most operating systems, including virtually 322all Unix-like platforms. See L<perlport/"Supported Platforms"> 323for a listing. 324 325=head1 ENVIRONMENT 326 327See L<perlrun>. 328 329=head1 AUTHOR 330 331Larry Wall <larry@wall.org>, with the help of oodles of other folks. 332 333If your Perl success stories and testimonials may be of help to others 334who wish to advocate the use of Perl in their applications, 335or if you wish to simply express your gratitude to Larry and the 336Perl developers, please write to perl-thanks@perl.org . 337 338=head1 FILES 339 340 "@INC" locations of perl libraries 341 342=head1 SEE ALSO 343 344 http://www.perl.org/ the Perl homepage 345 http://www.perl.com/ Perl articles (O'Reilly) 346 http://www.cpan.org/ the Comprehensive Perl Archive 347 http://www.pm.org/ the Perl Mongers 348 349=head1 DIAGNOSTICS 350 351Using the C<use strict> pragma ensures that all variables are properly 352declared and prevents other misuses of legacy Perl features. 353 354The C<use warnings> pragma produces some lovely diagnostics. One can 355also use the B<-w> flag, but its use is normally discouraged, because 356it gets applied to all executed Perl code, including that not under 357your control. 358 359See L<perldiag> for explanations of all Perl's diagnostics. The C<use 360diagnostics> pragma automatically turns Perl's normally terse warnings 361and errors into these longer forms. 362 363Compilation errors will tell you the line number of the error, with an 364indication of the next token or token type that was to be examined. 365(In a script passed to Perl via B<-e> switches, each 366B<-e> is counted as one line.) 367 368Setuid scripts have additional constraints that can produce error 369messages such as "Insecure dependency". See L<perlsec>. 370 371Did we mention that you should definitely consider using the B<use warnings> 372pragma? 373 374=head1 BUGS 375 376The behavior implied by the B<use warnings> pragma is not mandatory. 377 378Perl is at the mercy of your machine's definitions of various 379operations such as type casting, atof(), and floating-point 380output with sprintf(). 381 382If your stdio requires a seek or eof between reads and writes on a 383particular stream, so does Perl. (This doesn't apply to sysread() 384and syswrite().) 385 386While none of the built-in data types have any arbitrary size limits 387(apart from memory size), there are still a few arbitrary limits: a 388given variable name may not be longer than 251 characters. Line numbers 389displayed by diagnostics are internally stored as short integers, 390so they are limited to a maximum of 65535 (higher numbers usually being 391affected by wraparound). 392 393You may mail your bug reports (be sure to include full configuration 394information as output by the myconfig program in the perl source 395tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded 396in compiling perl, the L<perlbug> script in the F<utils/> subdirectory 397can be used to help mail in a bug report. 398 399Perl actually stands for Pathologically Eclectic Rubbish Lister, but 400don't tell anyone I said that. 401 402=head1 NOTES 403 404The Perl motto is "There's more than one way to do it." Divining 405how many more is left as an exercise to the reader. 406 407The three principal virtues of a programmer are Laziness, 408Impatience, and Hubris. See the Camel Book for why. 409 410