Hands-On System Programming with Go

Exit codes in bash

Every time a command gets executed in a shell, the resulting exit code gets stored in a variable. The status of the last command executed gets stored in the $? variable, and it can be printed as follows:

> echo  $? # will print 1

It is important to note that the exit code only works when you run a binary obtained with go build or go install. If you use go run, it will return 1 for any code that is not 0.