trim - convert all tabs to spaces and remove spaces at the end of lines

trim.sh

#!/bin/sh

die () {
    echo "$@" 1>&2
    exit 1
}

test -n "$1" || die "Usage: $0 file"

case "`stat --version 2>&1 | head -n1`" in
    *GNU*)
        stat="stat -c %a";;
    *)
        stat="stat -f %p";;
esac

while [ -n "$1" ]; do
    test -f "$1" || die "Cannot open file: $1"

    mode=`$stat "$1"`

    col -x < "$1" | expand > "$1.tmp-trim" \
    && test -s "$1.tmp-trim" \
    && chmod $mode "$1.tmp-trim" \
    && mv -f "$1.tmp-trim" "$1"

    shift
done