Return to Revisions

One common way is:

die() {
    echo "$*" 1>&2
    exit 1
}

then you use it like this:

mkdir -p some/path || die "mkdir failed with status $?"

Or if you want it to include the exit status, you could change it to:

die() {
    echo "FATAL ERROR: $* (status $?)" 1>&2
    exit 1
}

and then using it is a bit easier:

mkdir -p some/path || die "mkdir failed"

And your full example looks like:

mkdir -p some/path || die "mkdir failed"
cd some/path || die "cd failed"
run_some_command || die "some_command failed"

Just in case you haven't seen command1 || command2 before, it runs command1, and if command1 fails, it runs command2.

So you can read it like "make the directory or die".

Also, if you are going to use the name some/path multiple times, store it in a variable so you don't have to keep typing it, and can easily change it if you need to.

dir=some/path
mkdir -p "$dir" || die "Cannot make $dir"
cd "$dir" || die "Cannot cd to $dir"
run_some_command || die "Cannot run some_command"

And if you plan to fix the problem and re-run the script, maybe you want the script to work if the directory already exists, so you don't have to remove it first, in which case, you would want

dir=some/path
if [ ! -d "$dir" ]; then
    mkdir -p "$dir" || die "Cannot make $dir"
fi
cd "$dir" || die "Cannot cd to $dir"
run_some_command || die "Cannot run some_command"

If you find that hard to read, you could write it like:

dir=some/path
if [ ! -d "$dir" ]; then
    mkdir -p "$dir"        || die "Cannot make $dir"
fi
cd "$dir"                  || die "Cannot cd to $dir"
run_some_command           || die "Cannot run some_command"