Question

When bash is interpreting a script and encounters

${arg?error message}

when arg is unset, the script terminates after printing the error message. Unfortunately, bash prepends “$0: line $LINENO: arg:” to the error message. Is it possible to suppress the additional information? I would like the error message to be exactly “error message”.

Answer 1

You probably have to avoid the ${PARAMETER?WORD} construct and do it manually. For example, something like

if [ -z "${arg+set}" ]; then
    printf 'error message\n' >&2
    exit 2
fi