Developers new to Perl often overlook a very valuable source of information: perldoc. perldoc is Perl's documentation viewer; it allows you to read documentation in Perl's pod (plain old documentation) format. This provides a wealth of information about Perl, plus modules. Virtually every module included with Perl and available on CPAN includes pod.
If perl works on your system but the perldoc command does not, you may need to search your system for it. It is installed with Perl by default, but depending on the installation, it may not have been installed in a standard executable directory. You can also fall back to using man instead. pod pages are typically converted to manpages when they are installed.
To get started, try the following command:
$ perldoc perl
This provides a basic description of Perl along with a list of the Perl manual sections available. For instance, typing:
$ perldoc perlsec
will display the Perl security section. perldoc has a number of options; you can get the usage of perldoc this way:
$ perldoc perldoc
perldoc is very useful with modules. You can view the extensive documentation for CGI.pm this way:
$ perldoc CGI
This sequence works for multiple-word modules:
$ perldoc Digest::MD5
Note that the requested module must be present; perldoc does not fetch documentation from CPAN. In addition to package names, you can also supply a filename to perldoc; this allows you to view the documentation for a module before it is installed:
pod is typically stored within .pm files, although separate .pod files are possible.
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