#!/usr/bin/env bash exit_code=0 prereqs=( "bash" "flock" "mkdir" "mount" "umount" "eject" "blkid" "lsblk" "findmnt" "hdparm" "cryptsetup" ) for prereq in "${prereqs[@]}"; do echo -n "$prereq: " if ! command -v "$prereq"; then echo "NOT FOUND." exit_code=1 fi done exit $exit_code