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<https://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 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 perldocstyle Perl style guide for core docs 100 perlpodstyle Perl POD style guide 101 perldiag Perl diagnostic messages 102 perldeprecation Perl deprecations 103 perllexwarn Perl warnings and their control 104 perldebug Perl debugging 105 perlvar Perl predefined variables 106 perlre Perl regular expressions, the rest of the story 107 perlrebackslash Perl regular expression backslash sequences 108 perlrecharclass Perl regular expression character classes 109 perlreref Perl regular expressions quick reference 110 perlref Perl references, the rest of the story 111 perlform Perl formats 112 perlobj Perl objects 113 perltie Perl objects hidden behind simple variables 114 perldbmfilter Perl DBM filters 115 116 perlipc Perl interprocess communication 117 perlfork Perl fork() information 118 perlnumber Perl number semantics 119 120 perlthrtut Perl threads tutorial 121 122 perlport Perl portability guide 123 perllocale Perl locale support 124 perluniintro Perl Unicode introduction 125 perlunicode Perl Unicode support 126 perlunicook Perl Unicode cookbook 127 perlunifaq Perl Unicode FAQ 128 perluniprops Index of Unicode properties in Perl 129 perlunitut Perl Unicode tutorial 130 perlebcdic Considerations for running Perl on EBCDIC platforms 131 132 perlsec Perl security 133 perlsecpolicy Perl security report handling policy 134 135 perlmod Perl modules: how they work 136 perlmodlib Perl modules: how to write and use 137 perlmodstyle Perl modules: how to write modules with style 138 perlmodinstall Perl modules: how to install from CPAN 139 perlnewmod Perl modules: preparing a new module for distribution 140 perlpragma Perl modules: writing a user pragma 141 142 perlutil utilities packaged with the Perl distribution 143 144 perlfilter Perl source filters 145 146 perldtrace Perl's support for DTrace 147 148 perlglossary Perl Glossary 149 150=head2 Internals and C Language Interface 151 152 perlembed Perl ways to embed perl in your C or C++ application 153 perldebguts Perl debugging guts and tips 154 perlxstut Perl XS tutorial 155 perlxs Perl XS application programming interface 156 perlxstypemap Perl XS C/Perl type conversion tools 157 perlclib Internal replacements for standard C library functions 158 perlguts Perl internal functions for those doing extensions 159 perlcall Perl calling conventions from C 160 perlmroapi Perl method resolution plugin interface 161 perlreapi Perl regular expression plugin interface 162 perlreguts Perl regular expression engine internals 163 164 perlapi Perl API listing (autogenerated) 165 perlintern Perl internal functions (autogenerated) 166 perliol C API for Perl's implementation of IO in Layers 167 perlapio Perl internal IO abstraction interface 168 169 perlhack Perl hackers guide 170 perlsource Guide to the Perl source tree 171 perlinterp Overview of the Perl interpreter source and how it works 172 perlhacktut Walk through the creation of a simple C code patch 173 perlhacktips Tips for Perl core C code hacking 174 perlpolicy Perl development policies 175 perlgov Perl Rules of Governance 176 perlgit Using git with the Perl repository 177 178=head2 History 179 180 perlhist Perl history records 181 perldelta Perl changes since previous version 182 perl5341delta Perl changes in version 5.34.1 183 perl5340delta Perl changes in version 5.34.0 184 perl5321delta Perl changes in version 5.32.1 185 perl5320delta Perl changes in version 5.32.0 186 perl5303delta Perl changes in version 5.30.3 187 perl5302delta Perl changes in version 5.30.2 188 perl5301delta Perl changes in version 5.30.1 189 perl5300delta Perl changes in version 5.30.0 190 perl5283delta Perl changes in version 5.28.3 191 perl5282delta Perl changes in version 5.28.2 192 perl5281delta Perl changes in version 5.28.1 193 perl5280delta Perl changes in version 5.28.0 194 perl5263delta Perl changes in version 5.26.3 195 perl5262delta Perl changes in version 5.26.2 196 perl5261delta Perl changes in version 5.26.1 197 perl5260delta Perl changes in version 5.26.0 198 perl5244delta Perl changes in version 5.24.4 199 perl5243delta Perl changes in version 5.24.3 200 perl5242delta Perl changes in version 5.24.2 201 perl5241delta Perl changes in version 5.24.1 202 perl5240delta Perl changes in version 5.24.0 203 perl5224delta Perl changes in version 5.22.4 204 perl5223delta Perl changes in version 5.22.3 205 perl5222delta Perl changes in version 5.22.2 206 perl5221delta Perl changes in version 5.22.1 207 perl5220delta Perl changes in version 5.22.0 208 perl5203delta Perl changes in version 5.20.3 209 perl5202delta Perl changes in version 5.20.2 210 perl5201delta Perl changes in version 5.20.1 211 perl5200delta Perl changes in version 5.20.0 212 perl5184delta Perl changes in version 5.18.4 213 perl5182delta Perl changes in version 5.18.2 214 perl5181delta Perl changes in version 5.18.1 215 perl5180delta Perl changes in version 5.18.0 216 perl5163delta Perl changes in version 5.16.3 217 perl5162delta Perl changes in version 5.16.2 218 perl5161delta Perl changes in version 5.16.1 219 perl5160delta Perl changes in version 5.16.0 220 perl5144delta Perl changes in version 5.14.4 221 perl5143delta Perl changes in version 5.14.3 222 perl5142delta Perl changes in version 5.14.2 223 perl5141delta Perl changes in version 5.14.1 224 perl5140delta Perl changes in version 5.14.0 225 perl5125delta Perl changes in version 5.12.5 226 perl5124delta Perl changes in version 5.12.4 227 perl5123delta Perl changes in version 5.12.3 228 perl5122delta Perl changes in version 5.12.2 229 perl5121delta Perl changes in version 5.12.1 230 perl5120delta Perl changes in version 5.12.0 231 perl5101delta Perl changes in version 5.10.1 232 perl5100delta Perl changes in version 5.10.0 233 perl589delta Perl changes in version 5.8.9 234 perl588delta Perl changes in version 5.8.8 235 perl587delta Perl changes in version 5.8.7 236 perl586delta Perl changes in version 5.8.6 237 perl585delta Perl changes in version 5.8.5 238 perl584delta Perl changes in version 5.8.4 239 perl583delta Perl changes in version 5.8.3 240 perl582delta Perl changes in version 5.8.2 241 perl581delta Perl changes in version 5.8.1 242 perl58delta Perl changes in version 5.8.0 243 perl561delta Perl changes in version 5.6.1 244 perl56delta Perl changes in version 5.6 245 perl5005delta Perl changes in version 5.005 246 perl5004delta Perl changes in version 5.004 247 248=head2 Miscellaneous 249 250 perlbook Perl book information 251 perlcommunity Perl community information 252 253 perldoc Look up Perl documentation in Pod format 254 255 perlexperiment A listing of experimental features in Perl 256 257 perlartistic Perl Artistic License 258 perlgpl GNU General Public License 259 260=head2 Language-Specific 261 262=for buildtoc flag +r 263 264 perlcn Perl for Simplified Chinese (in UTF-8) 265 perljp Perl for Japanese (in EUC-JP) 266 perlko Perl for Korean (in EUC-KR) 267 perltw Perl for Traditional Chinese (in Big5) 268 269=head2 Platform-Specific 270 271 perlaix Perl notes for AIX 272 perlamiga Perl notes for AmigaOS 273 perlandroid Perl notes for Android 274 perlbs2000 Perl notes for POSIX-BC BS2000 275 perlcygwin Perl notes for Cygwin 276 perlfreebsd Perl notes for FreeBSD 277 perlhaiku Perl notes for Haiku 278 perlhpux Perl notes for HP-UX 279 perlhurd Perl notes for Hurd 280 perlirix Perl notes for Irix 281 perllinux Perl notes for Linux 282 perlmacosx Perl notes for Mac OS X 283 perlopenbsd Perl notes for OpenBSD 284 perlos2 Perl notes for OS/2 285 perlos390 Perl notes for OS/390 286 perlos400 Perl notes for OS/400 287 perlplan9 Perl notes for Plan 9 288 perlqnx Perl notes for QNX 289 perlriscos Perl notes for RISC OS 290 perlsolaris Perl notes for Solaris 291 perlsynology Perl notes for Synology 292 perltru64 Perl notes for Tru64 293 perlvms Perl notes for VMS 294 perlvos Perl notes for Stratus VOS 295 perlwin32 Perl notes for Windows 296 297=for buildtoc flag -r 298 299=head2 Stubs for Deleted Documents 300 301 perlboot 302 perlbot 303 perlrepository 304 perltodo 305 perltooc 306 perltoot 307 308=for buildtoc __END__ 309 310On a Unix-like system, these documentation files will usually also be 311available as manpages for use with the F<man> program. 312 313Some documentation is not available as man pages, so if a 314cross-reference is not found by man, try it with L<perldoc>. Perldoc can 315also take you directly to documentation for functions (with the B<-f> 316switch). See C<perldoc --help> (or C<perldoc perldoc> or C<man perldoc>) 317for other helpful options L<perldoc> has to offer. 318 319In general, if something strange has gone wrong with your program and you're 320not sure where you should look for help, try making your code comply with 321B<use strict> and B<use warnings>. These will often point out exactly 322where the trouble is. 323 324=head1 DESCRIPTION 325 326Perl officially stands for Practical Extraction and Report Language, 327except when it doesn't. 328 329Perl was originally a language optimized for scanning arbitrary 330text files, extracting information from those text files, and printing 331reports based on that information. It quickly became a good language 332for many system management tasks. Over the years, Perl has grown into 333a general-purpose programming language. It's widely used for everything 334from quick "one-liners" to full-scale application development. 335 336The language is intended to be practical (easy to use, efficient, 337complete) rather than beautiful (tiny, elegant, minimal). It combines 338(in the author's opinion, anyway) some of the best features of B<sed>, 339B<awk>, and B<sh>, making it familiar and easy to use for Unix users to 340whip up quick solutions to annoying problems. Its general-purpose 341programming facilities support procedural, functional, and 342object-oriented programming paradigms, making Perl a comfortable 343language for the long haul on major projects, whatever your bent. 344 345Perl's roots in text processing haven't been forgotten over the years. 346It still boasts some of the most powerful regular expressions to be 347found anywhere, and its support for Unicode text is world-class. It 348handles all kinds of structured text, too, through an extensive 349collection of extensions. Those libraries, collected in the CPAN, 350provide ready-made solutions to an astounding array of problems. When 351they haven't set the standard themselves, they steal from the best 352-- just like Perl itself. 353 354=head1 AVAILABILITY 355 356Perl is available for most operating systems, including virtually 357all Unix-like platforms. See L<perlport/"Supported Platforms"> 358for a listing. 359 360=head1 ENVIRONMENT 361 362See L<perlrun/ENVIRONMENT>. 363 364=head1 AUTHOR 365 366Larry Wall <larry@wall.org>, with the help of oodles of other folks. 367 368If your Perl success stories and testimonials may be of help to others 369who wish to advocate the use of Perl in their applications, 370or if you wish to simply express your gratitude to Larry and the 371Perl developers, please write to perl-thanks@perl.org . 372 373=head1 FILES 374 375 "@INC" locations of perl libraries 376 377"@INC" above is a reference to the built-in variable of the same name; 378see L<perlvar> for more information. 379 380=head1 SEE ALSO 381 382 https://www.perl.org/ the Perl homepage 383 https://www.perl.com/ Perl articles 384 https://www.cpan.org/ the Comprehensive Perl Archive 385 https://www.pm.org/ the Perl Mongers 386 387=head1 DIAGNOSTICS 388 389Using the C<use strict> pragma ensures that all variables are properly 390declared and prevents other misuses of legacy Perl features. 391These are enabled by default within the scope of 392C<L<use v5.12|perlfunc/use VERSION>> (or higher). 393 394The C<use warnings> pragma produces some lovely diagnostics. 395It is enabled by default when you say C<use v5.35> (or higher). 396One can also use the B<-w> flag, but its use is normally discouraged, 397because it gets applied to all executed Perl code, including that not under 398your control. 399 400See L<perldiag> for explanations of all Perl's diagnostics. The C<use 401diagnostics> pragma automatically turns Perl's normally terse warnings 402and errors into these longer forms. 403 404Compilation errors will tell you the line number of the error, with an 405indication of the next token or token type that was to be examined. 406(In a script passed to Perl via B<-e> switches, each 407B<-e> is counted as one line.) 408 409Setuid scripts have additional constraints that can produce error 410messages such as "Insecure dependency". See L<perlsec>. 411 412Did we mention that you should definitely consider using the B<use warnings> 413pragma? 414 415=head1 BUGS 416 417The behavior implied by the B<use warnings> pragma is not mandatory. 418 419Perl is at the mercy of your machine's definitions of various 420operations such as type casting, atof(), and floating-point 421output with sprintf(). 422 423If your stdio requires a seek or eof between reads and writes on a 424particular stream, so does Perl. (This doesn't apply to sysread() 425and syswrite().) 426 427While none of the built-in data types have any arbitrary size limits 428(apart from memory size), there are still a few arbitrary limits: a 429given variable name may not be longer than 251 characters. Line numbers 430displayed by diagnostics are internally stored as short integers, 431so they are limited to a maximum of 65535 (higher numbers usually being 432affected by wraparound). 433 434You may submit your bug reports (be sure to include full configuration 435information as output by the myconfig program in the perl source 436tree, or by C<perl -V>) to L<https://github.com/Perl/perl5/issues>. 437 438Perl actually stands for Pathologically Eclectic Rubbish Lister, but 439don't tell anyone I said that. 440 441=head1 NOTES 442 443The Perl motto is "There's more than one way to do it." Divining 444how many more is left as an exercise to the reader. 445 446The three principal virtues of a programmer are Laziness, 447Impatience, and Hubris. See the Camel Book for why. 448 449