Shell script to add a system user

add-sysuser.sh

#!/bin/bash -e
# Add a system user in Linux

if [ $UID -ne 0 ]; then
    echo "You must be a root / superuser, in order to run this script. $(basename $0) aborted."
    exit 1
fi

if [ $# -ne 3 ]; then
	echo "Usage: $(basename $0) <user-name> <user-home> <gecos-string>"
	exit 2
fi

echo "Adding system-user $1 with home-dir at $2 and description $3 ..."
adduser --system --shell /bin/bash --gecos '$3' --group --disabled-password --home $2 $1
echo "DONE."

exit 0