EEM - exit status variable
When using Cisco's Embedded Event Manager (EEM) to write the script for an applet, the set command is used to set the exit status variable.
The exit status variable is used to represent either a successful exit or a failed exit from the applet. An exit status of 0 represents a successful exit status. A non-zero value like “1” represents a failed exit status.
Exit status values can range from 0 to 255. Typically, the values of the exit status will be either 0 or 1 to represent success or failure. However, values 2-255 can be used to specify specific reasons for a failure. By default these are not used, but you can configure them for more complex EEM scripts to issue a different exit value depending upon why the script failed.
Links
https://forum.networklessons.com/t/cisco-ios-embedded-event-manager-eem/1106/48?u=lagapidis