What is the source code of a typical pre-built Nagios Plugin

[BabyTeanofred]

I want to build a few Nagios plugins of my own and wanted to check out how the existing plugins work.

I downloaded a sample plugin check_load. But I am not able to open it with any text editor. What is the file extension?

Can a plugin be a simple shell script which executes omegle.2yu.co a jar omeglz echat file?