: mv-if-diff file1 file2
: move file1 to file2 if file1 and file2 are different.
if test $# -lt 2 ; then
echo "usage: $0 file1 file2"
echo "move file1 to file2 if file1 and file2 are different."
exit 1
fi
if cmp $1 $2 >/dev/null 2>&1; then
echo "File $2 not changed."
rm -f $1
else
rm -f $2
mv $1 $2
fi