os.execute()
os.execute() returns [3 variables](f59e6a93c0/lauxlib.c (L286)). Capture the 2nd (e.g. "exit") and 3rd (e.g. 0) in addition to the first which would be merely `true` on success or `nil` on error.
f59e6a93c0/lauxlib.c (L286)