check_cpu – % used

Project Notes

The pourpose of this plugin is to be the simplest check_cpu as possible. Following the unix philosophy of simplicity and code/tools reusability, it was created aiming maximum use of largely available tools and minimum own code, and even this minumum code is written in (super-simple and highly-portable) Bourne Shell script. This simplicity was really easy to achieve, since there are already pretty common linux command-line tools that actually do all the dirt job =). So, in the hopes that this little script may be useful for someone, I present you with this straight-forward, super-simple, zero-bloated, with-no-obscure-dependencies, Bourne Shell script for CPU checking in Linux systems (may work on others POSIX systems too). The plugin simply tests the existance of procinfo and sar, and uses whichever of them is available (if none of them is available, the plugin fails). Then, it executes the external program grabbing the line which tells the average idle time. From this, it simply deduces the used % and print it suitable for nagios input. Nothing more =)