Exit Codes: A Validator Other Scripts Can Branch On

MediumShell Scripting15-25 min

The brief

Write a small validator at /usr/local/bin/check-cfg that takes one argument — a config file path — and returns a distinct exit status per condition, so a calling script can branch on it:

called with no argument → print a usage message to stderr, exit with the usage code
argument names a missing file → exit with the missing-file code
argument names an existing file → exit 0

The exact codes are in /root/case/brief.txt (they vary per session — read them). Grading runs your script for each case and checks $?. Make it executable.

What you'll do

Handle argument count with $# and read $1
Return distinct, meaningful exit codes per condition
Write a script whose status a caller can branch on

Hands-on lab: you work on a real Linux box in your browser, graded on the machine's actual state.