KEEP *.map function DATA { for f do test -f $f && continue case $f in chown.map) print $(id -nu):$(id -ng) 1:2 ;; esac > $f done } TEST 01 maps DO DATA chown.map EXEC -nX -m chown.map chown.map OUTPUT - $'chown uid:00000->00001 gid:00000->00002 chown.map'