Nagios also offers plugins for many other operations that are common to daily system monitoring and activities; this section covers only a few of them. It is recommended that you look for remaining commands in both the Nagios plugins package as well as on the Nagios Exchange website.
Many Linux distributions use Advanced Packaging Tool (APT) for handling package management (visit http://en.wikipedia.org/wiki/Advanced_Packaging_Tool). This tool is used by default on Debian and its derivatives such as Ubuntu. It allows the handling of upgrades and download of packages. It also allows the synchronization of package lists from one or more remote sources.
Nagios provides a plugin that allows you to monitor, if any upgrades are available, and/or perform upgrades automatically. The syntax and options are as follows:
check_apt [–d|-u|-U [<opts>]] [-n] [-t timeout] [-i <regex>] [-e <regex>] [-c <regex>]