Nagios, 2nd Edition

25.2 The Perl Online Documentation

The Perl Online Documentation (POD) is a simple markup language, which is based on conventional man pages. It enables you to include the documentation for a Perl script in the script itself. The command perldoc script provides this ready-formatted:^[298]

#!/usr/bin/perl -w
=head1 NAME

check_du.pl - Nagios plugin for checking size of directories and files

=head1 SYNOPSIS

check_du.pl -P path/pattern [-v] [-w warning_threshold] [-c critical_threshold]
check_du.pl [-h|-V]

=head1 OPTIONS

=over 4

=item -P|--path=expression

Path expression for calculating size. May be a shell expression like /var/log/*.log

=item -w|--warning=threshold threshold can be max (warn if < 0 or > max), min:max (warn if < min or > max), min: ...