#! /bin/bash DATABASE=${DATABASE:-/tmp/docker-mailserver/postfix-accounts.cf} USER="$1" usage() { echo "Usage: delmailuser " } errex() { echo "$@" 1>&2 exit 1 } escape() { echo "${1//./\\.}" } [ -z "$USER" ] && { usage; errex "No user specifed"; } [ -s "$DATABASE" ] || exit 0 # XXX $USER must not contain /s and other syntactic characters sed -i "/^$(escape "$USER")|/d" $DATABASE