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 c2ph h2ph h2xs perlbug pl2pm pod2html pod2man 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 perl5241delta Perl changes in version 5.24.1 184 perl5240delta Perl changes in version 5.24.0 185 perl5223delta Perl changes in version 5.22.3 186 perl5222delta Perl changes in version 5.22.2 187 perl5221delta Perl changes in version 5.22.1 188 perl5220delta Perl changes in version 5.22.0 189 perl5203delta Perl changes in version 5.20.3 190 perl5202delta Perl changes in version 5.20.2 191 perl5201delta Perl changes in version 5.20.1 192 perl5200delta Perl changes in version 5.20.0 193 perl5184delta Perl changes in version 5.18.4 194 perl5182delta Perl changes in version 5.18.2 195 perl5181delta Perl changes in version 5.18.1 196 perl5180delta Perl changes in version 5.18.0 197 perl5163delta Perl changes in version 5.16.3 198 perl5162delta Perl changes in version 5.16.2 199 perl5161delta Perl changes in version 5.16.1 200 perl5160delta Perl changes in version 5.16.0 201 perl5144delta Perl changes in version 5.14.4 202 perl5143delta Perl changes in version 5.14.3 203 perl5142delta Perl changes in version 5.14.2 204 perl5141delta Perl changes in version 5.14.1 205 perl5140delta Perl changes in version 5.14.0 206 perl5125delta Perl changes in version 5.12.5 207 perl5124delta Perl changes in version 5.12.4 208 perl5123delta Perl changes in version 5.12.3 209 perl5122delta Perl changes in version 5.12.2 210 perl5121delta Perl changes in version 5.12.1 211 perl5120delta Perl changes in version 5.12.0 212 perl5101delta Perl changes in version 5.10.1 213 perl5100delta Perl changes in version 5.10.0 214 perl589delta Perl changes in version 5.8.9 215 perl588delta Perl changes in version 5.8.8 216 perl587delta Perl changes in version 5.8.7 217 perl586delta Perl changes in version 5.8.6 218 perl585delta Perl changes in version 5.8.5 219 perl584delta Perl changes in version 5.8.4 220 perl583delta Perl changes in version 5.8.3 221 perl582delta Perl changes in version 5.8.2 222 perl581delta Perl changes in version 5.8.1 223 perl58delta Perl changes in version 5.8.0 224 perl561delta Perl changes in version 5.6.1 225 perl56delta Perl changes in version 5.6 226 perl5005delta Perl changes in version 5.005 227 perl5004delta Perl changes in version 5.004 228 229 perlexperiment A listing of experimental features in Perl 230 231 perlartistic Perl Artistic License 232 perlgpl GNU General Public License 233 234=head2 Language-Specific 235 236=for buildtoc flag +r 237 238 perlcn Perl for Simplified Chinese (in EUC-CN) 239 perljp Perl for Japanese (in EUC-JP) 240 perlko Perl for Korean (in EUC-KR) 241 perltw Perl for Traditional Chinese (in Big5) 242 243=head2 Platform-Specific 244 245 perlaix Perl notes for AIX 246 perlamiga Perl notes for AmigaOS 247 perlandroid Perl notes for Android 248 perlbs2000 Perl notes for POSIX-BC BS2000 249 perlce Perl notes for WinCE 250 perlcygwin Perl notes for Cygwin 251 perldos Perl notes for DOS 252 perlfreebsd Perl notes for FreeBSD 253 perlhaiku Perl notes for Haiku 254 perlhpux Perl notes for HP-UX 255 perlhurd Perl notes for Hurd 256 perlirix Perl notes for Irix 257 perllinux Perl notes for Linux 258 perlmacos Perl notes for Mac OS (Classic) 259 perlmacosx Perl notes for Mac OS X 260 perlnetware Perl notes for NetWare 261 perlopenbsd Perl notes for OpenBSD 262 perlos2 Perl notes for OS/2 263 perlos390 Perl notes for OS/390 264 perlos400 Perl notes for OS/400 265 perlplan9 Perl notes for Plan 9 266 perlqnx Perl notes for QNX 267 perlriscos Perl notes for RISC OS 268 perlsolaris Perl notes for Solaris 269 perlsymbian Perl notes for Symbian 270 perlsynology Perl notes for Synology 271 perltru64 Perl notes for Tru64 272 perlvms Perl notes for VMS 273 perlvos Perl notes for Stratus VOS 274 perlwin32 Perl notes for Windows 275 276=for buildtoc flag -r 277 278=head2 Stubs for Deleted Documents 279 280 perlboot 281 perlbot 282 perlrepository 283 perltodo 284 perltooc 285 perltoot 286 287=for buildtoc __END__ 288 289On a Unix-like system, these documentation files will usually also be 290available as manpages for use with the F<man> program. 291 292Some documentation is not available as man pages, so if a 293cross-reference is not found by man, try it with L<perldoc>. Perldoc can 294also take you directly to documentation for functions (with the B<-f> 295switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>) 296for other helpful options L<perldoc> has to offer. 297 298In general, if something strange has gone wrong with your program and you're 299not sure where you should look for help, try making your code comply with 300B<use strict> and B<use warnings>. These will often point out exactly 301where the trouble is. 302 303=head1 DESCRIPTION 304 305Perl officially stands for Practical Extraction and Report Language, 306except when it doesn't. 307 308Perl was originally a language optimized for scanning arbitrary 309text files, extracting information from those text files, and printing 310reports based on that information. It quickly became a good language 311for many system management tasks. Over the years, Perl has grown into 312a general-purpose programming language. It's widely used for everything 313from quick "one-liners" to full-scale application development. 314 315The language is intended to be practical (easy to use, efficient, 316complete) rather than beautiful (tiny, elegant, minimal). It combines 317(in the author's opinion, anyway) some of the best features of B<sed>, 318B<awk>, and B<sh>, making it familiar and easy to use for Unix users to 319whip up quick solutions to annoying problems. Its general-purpose 320programming facilities support procedural, functional, and 321object-oriented programming paradigms, making Perl a comfortable 322language for the long haul on major projects, whatever your bent. 323 324Perl's roots in text processing haven't been forgotten over the years. 325It still boasts some of the most powerful regular expressions to be 326found anywhere, and its support for Unicode text is world-class. It 327handles all kinds of structured text, too, through an extensive 328collection of extensions. Those libraries, collected in the CPAN, 329provide ready-made solutions to an astounding array of problems. When 330they haven't set the standard themselves, they steal from the best 331-- just like Perl itself. 332 333=head1 AVAILABILITY 334 335Perl is available for most operating systems, including virtually 336all Unix-like platforms. See L<perlport/"Supported Platforms"> 337for a listing. 338 339=head1 ENVIRONMENT 340 341See L<perlrun>. 342 343=head1 AUTHOR 344 345Larry Wall <larry@wall.org>, with the help of oodles of other folks. 346 347If your Perl success stories and testimonials may be of help to others 348who wish to advocate the use of Perl in their applications, 349or if you wish to simply express your gratitude to Larry and the 350Perl developers, please write to perl-thanks@perl.org . 351 352=head1 FILES 353 354 "@INC" locations of perl libraries 355 356"@INC" above is a reference to the built-in variable of the same name; 357see L<perlvar> for more information. 358 359=head1 SEE ALSO 360 361 http://www.perl.org/ the Perl homepage 362 http://www.perl.com/ Perl articles (O'Reilly) 363 http://www.cpan.org/ the Comprehensive Perl Archive 364 http://www.pm.org/ the Perl Mongers 365 366=head1 DIAGNOSTICS 367 368Using the C<use strict> pragma ensures that all variables are properly 369declared and prevents other misuses of legacy Perl features. 370 371The C<use warnings> pragma produces some lovely diagnostics. One can 372also use the B<-w> flag, but its use is normally discouraged, because 373it gets applied to all executed Perl code, including that not under 374your control. 375 376See L<perldiag> for explanations of all Perl's diagnostics. The C<use 377diagnostics> pragma automatically turns Perl's normally terse warnings 378and errors into these longer forms. 379 380Compilation errors will tell you the line number of the error, with an 381indication of the next token or token type that was to be examined. 382(In a script passed to Perl via B<-e> switches, each 383B<-e> is counted as one line.) 384 385Setuid scripts have additional constraints that can produce error 386messages such as "Insecure dependency". See L<perlsec>. 387 388Did we mention that you should definitely consider using the B<use warnings> 389pragma? 390 391=head1 BUGS 392 393The behavior implied by the B<use warnings> pragma is not mandatory. 394 395Perl is at the mercy of your machine's definitions of various 396operations such as type casting, atof(), and floating-point 397output with sprintf(). 398 399If your stdio requires a seek or eof between reads and writes on a 400particular stream, so does Perl. (This doesn't apply to sysread() 401and syswrite().) 402 403While none of the built-in data types have any arbitrary size limits 404(apart from memory size), there are still a few arbitrary limits: a 405given variable name may not be longer than 251 characters. Line numbers 406displayed by diagnostics are internally stored as short integers, 407so they are limited to a maximum of 65535 (higher numbers usually being 408affected by wraparound). 409 410You may mail your bug reports (be sure to include full configuration 411information as output by the myconfig program in the perl source 412tree, or by C<perl -V>) to perlbug@perl.org . If you've succeeded 413in compiling perl, the L<perlbug> script in the F<utils/> subdirectory 414can be used to help mail in a bug report. 415 416Perl actually stands for Pathologically Eclectic Rubbish Lister, but 417don't tell anyone I said that. 418 419=head1 NOTES 420 421The Perl motto is "There's more than one way to do it." Divining 422how many more is left as an exercise to the reader. 423 424The three principal virtues of a programmer are Laziness, 425Impatience, and Hubris. See the Camel Book for why. 426 427