#### If different, global variable "failed" is incremented.
check() {
#### POSIX diff should support -c.
- if diff -c "$1" "$2"; then
+ if cmp -s "$1" "$2"; then
test $# -lt 3 -o "$3" != 'keep first' && rm -f "$1"
rm -f "$2"
else
+ echo
+ diff -c "$1" "$2"
+ echo
echo "$0: test failed, outputs are in $1 and $2."
failed=`expr ${failed:-0} + 1`
fi