1: mv-if-diff file1 file2
2: move file1 to file2 if file1 and file2 are different.
3
4if test $# -lt 2 ; then
5	echo "usage:  $0 file1 file2"
6	echo "move file1 to file2 if file1 and file2 are different."
7	exit 1
8fi
9if cmp $1 $2 >/dev/null 2>&1; then
10	echo "File $2 not changed."
11	rm -f $1
12else
13	rm -f $2
14	mv $1 $2
15fi
16