#!/bin/sh
for i in "$@"; do
    num=`grep '^F' "$i" | awk '{printf ("%03d\n", strtonum("0x" $4))}'`
    case "$num" in
	"")
	echo "$i: no flight number found" 1>&2
	;;
	*)
	newname=`echo "$i" | sed 's/flight-[0-9][0-9][0-9]/flight-'"$num"'/'`
	echo $num "$i" "$newname"
	;;
    esac
done | sort -rn | sed 's/^[0-9][0-9]*//' | while read old new; do
    if [ $new = $old ]; then
	:
    else
	if [ -f $new ]; then
	    if cmp $new $old; then
		echo "$old is a duplicate of $new"
		rm $old
	    else
		echo "$old: $new already exists"
	    fi
	else
	    echo mv $old $new
	fi
    fi
done