#!/bin/bash
pname=$(basename $0)
fchmod=a+r
dchmod=a+rx

PATH=/usr/bin:/bin

function usage () {
    echo "${pname} usage:"
    echo "    ${pname} [-ro|--read-only|-u|--owner|-g|--group] directory..."
    echo " default      everybody can read, leave write as is."
    echo " --read-only  nobody can write anything."
    echo " --owner      only owner may write directories or files."
    echo " --group      only owner and group may write directories or files."
    echo ""
    echo "   555 / 444    --read-only -ro"
    echo "   755 / 644    --owner     -u "
    echo "   775 / 664    --group     -g "
}

for arg ; do
    case "$arg" in
    --read-only|-ro)
        fchmod=a+r,a-w
        dchmod=a+rx,a-w
        ;;
    --owner|-u)
        fchmod=a+r,u+w,go-w
        dchmod=a+rx,u+w,go-w
        ;;
    --group|-g)
        fchmod=a+r,ug+w,o-w
        dchmod=a+rx,ug+w,o-w
        ;;
    --help|-h)
        usage
        exit 0
        ;;
    -*)
        echo "${pname}: Invalid option '$arg'."
        usage
        exit 1
        ;;
    *)
        find "$arg" -type d             -exec chmod $dchmod      {} \; &
        find "$arg" -type f             -exec chmod $fchmod,og-x {} \; \
                            -perm -0100 -exec chmod a+x          {} \; &
        ;;
    esac
done
wait
#END#