#!/bin/sh 

# x-random-bitmap -- places a random bitmap as root window background
# $Id$
# Carlos Duarte <cgd@teleweb.pt>, 970325

USAGE='
	eval cat<<EOF
usage: $0 -d bitmap_dirs 
EOF
	exit 1
'

while : ; do
	case x"$1" in 
	x-h)	eval "$USAGE" ;;
	x-d)	D="$2"; shift ;;
	x--)	shift; break ;;
	x-*)	echo "invalid option -- `echo $1|cut -c2-`"
		eval "$USAGE" ;;
	*)	break ;;
	esac
	shift
done
test $# -eq 0 || eval "$USAGE" 
test "$D" = "" && eval "$USAGE"

if test -d "$D"; then : ; else
	echo "$D: bad dir"
	exit 1
fi

ls "$D" | awk '
BEGIN { srand(); i = 0 }
$0 == "." || $0 == ".." { next } 
{ f[i] = $0; i = i+1 }
END {
	for ( j = 0; j < (i-1); j++ ) {
		n = int ( rand() * 953 ) % ( i - j ) 
		x = f[j]; 
		f[j] = f[n]; 
		f[n] = x; 
	}
	for (;;) for ( j = 0; j < i; j++) {
		printf "xsetroot -fg black -bg lightblue -bitmap %s/", "'"$D"'"
		printf "%s; sleep 120\n", f[j] 
	}
}' | sh