- [ -n "${VOL_SRC+yes}" ] && umount "${VOL_SRC}" && rmdir "${VOL_SRC}" && unset VOL_SRC
- [ -e "/dev/mapper/crypt-src" ] && cryptsetup luksClose crypt-src
- [ -n "${LOOP_SRC+yes}" ] && losetup -d "${LOOP_SRC}" && unset LOOP_SRC
+ [[ -n "${VOL_SRC+yes}" ]] && umount "${VOL_SRC}" && rmdir "${VOL_SRC}" && unset VOL_SRC
+ [[ -e "/dev/mapper/crypt-src" ]] && cryptsetup luksClose crypt-src
+ [[ -n "${LOOP_SRC+yes}" ]] && losetup -d "${LOOP_SRC}" && unset LOOP_SRC