# make sure redo doesn't think merely *reading* the old file counts as
# modifying it in-place.
cat $1 >/dev/null 2>/dev/null || true
-${PYTHON:-python} tick.py
+perl -mTime::HiRes -e '
+ $t2 = 1 + int(Time::HiRes::time());
+ while (1) {
+ $t = Time::HiRes::time();
+ last if $t > $t2;
+ sleep($t2 - $t + 0.01);
+ };
+'
cat $1 >/dev/null 2>/dev/null || true
echo hello