# phpman > perldoc > cp ## Found in /usr/share/perl/5.34/pod/perlfaq2.pod What modules and extensions are available for Perl? What is CPAN? CPAN stands for Comprehensive Perl Archive Network, a multi-gigabyte archive replicated on hundreds of machines all over the world. CPAN contains tens of thousands of modules and extensions, source code and documentation, designed for *everything* from commercial database interfaces to keyboard/screen control and running large web sites. You can search CPAN on <>. The master web site for CPAN is <>, <> lists all mirrors. See the CPAN FAQ at <> for answers to the most frequently asked questions about CPAN. The [Task::Kensho](https://www.chedong.com/phpMan.php/perldoc/Task%3A%3AKensho/markdown) module has a list of recommended modules which you should review as a good starting point. What is perl.com? Perl Mongers? pm.org? perl.org? cpan.org? Perl.com <> used to be part of the O'Reilly Network, a subsidiary of O'Reilly Media. Although it retains most of the original content from its O'Reilly Network, it is now hosted by The Perl Foundation <>. The Perl Foundation is an advocacy organization for the Perl language which maintains the web site <> as a general advocacy site for the Perl language. It uses the domain to provide general support services to the Perl community, including the hosting of mailing lists, web sites, and other services. There are also many other sub-domains for special topics like learning Perl and jobs in Perl, such as: * <> * <> * <> * <> Perl Mongers <> uses the pm.org domain for services related to local Perl user groups, including the hosting of mailing lists and web sites. See the Perl Mongers web site <> for more information about joining, starting, or requesting services for a Perl user group. CPAN, or the Comprehensive Perl Archive Network <>, is a replicated, worldwide repository of Perl software. See What is CPAN?. ## Found in /usr/share/perl/5.34/pod/perlfaq3.pod Where can I get perl-mode or cperl-mode for emacs? Since Emacs version 19 patchlevel 22 or so, there have been both a perl-mode.el and support for the Perl debugger built in. These should come with the standard Emacs 19 distribution. Note that the perl-mode of emacs will have fits with "main'foo" (single quote), and mess up the indentation and highlighting. You are probably using "[main::foo](https://www.chedong.com/phpMan.php/perldoc/main%3A%3Afoo/markdown)" in new Perl code anyway, so this shouldn't be an issue. For CPerlMode, see <> ## Found in /usr/share/perl/5.34/pod/perlfaq7.pod How do I adopt or take over a module already on CPAN? Ask the current maintainer to make you a co-maintainer or transfer the module to you. If you can not reach the author for some reason contact the PAUSE admins at who may be able to help, but each case is treated separately. * Get a login for the Perl Authors Upload Server (PAUSE) if you don't already have one: <> * Write to explaining what you did to contact the current maintainer. The PAUSE admins will also try to reach the maintainer. * Post a public message in a heavily trafficked site announcing your intention to take over the module. * Wait a bit. The PAUSE admins don't want to act too quickly in case the current maintainer is on holiday. If there's no response to private communication or the public post, a PAUSE admin can transfer it to you. ## Found in /usr/share/perl/5.34/pod/perlfaq8.pod How do I set CPU limits? (contributed by Xho) Use the [BSD::Resource](https://www.chedong.com/phpMan.php/perldoc/BSD%3A%3AResource/markdown) module from CPAN. As an example: use [BSD::Resource](https://www.chedong.com/phpMan.php/perldoc/BSD%3A%3AResource/markdown); setrlimit(RLIMIT_CPU,10,20) or die $!; This sets the soft and hard limits to 10 and 20 seconds, respectively. After 10 seconds of time spent running on the CPU (not "wall" time), the process will be sent a signal (XCPU on some systems) which, if not trapped, will cause the process to terminate. If that signal is trapped, then after 10 more seconds (20 seconds in total) the process will be killed with a non-trappable signal. See the [BSD::Resource](https://www.chedong.com/phpMan.php/perldoc/BSD%3A%3AResource/markdown) and your systems documentation for the gory details. How do I install a module from CPAN? (contributed by brian d foy) The easiest way is to have a module also named CPAN do it for you by using the "cpan" command that comes with Perl. You can give it a list of modules to install: $ cpan [IO::Interactive](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AInteractive/markdown) [Getopt::Whatever](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3AWhatever/markdown) If you prefer "CPANPLUS", it's just as easy: $ cpanp i [IO::Interactive](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3AInteractive/markdown) [Getopt::Whatever](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3AWhatever/markdown) If you want to install a distribution from the current directory, you can tell "CPAN.pm" to install "." (the full stop): $ cpan . See the documentation for either of those commands to see what else you can do. If you want to try to install a distribution by yourself, resolving all dependencies on your own, you follow one of two possible build paths. For distributions that use *Makefile.PL*: $ perl Makefile.PL $ make test install For distributions that use *Build.PL*: $ perl Build.PL $ ./Build test $ ./Build install Some distributions may need to link to libraries or other third-party code and their build and installation sequences may be more complicated. Check any *README* or *INSTALL* files that you may find.