When measuring elapsed times, instead of executing date(1) to get the current time, use $SECONDS: SECONDS Each time this parameter is refe

When measuring elapsed times, instead of executing date(1) to get the current time, use $SECONDS: SECONDS Each time this parameter is referenced, the number of seconds since shell invocation is returned. If a value is assigned to SECONDS, the value returned upon subsequent references is the number of seconds since the assignment plus the value assigned. If SECONDS is unset, it loses its special properties, even if it is subsequently reset. Like so: throttle() { local -i limit ((limit = SECONDS + $1)) while read line; do if ((limit < SECONDS)); then ((limit = SECONDS + $1)) echo "$line" fi done } Try it like so: $ yes | throttle 2 Of course, that's a bad example in that yes(1) will go as fast as you let it and it always outputs the same thing. In the case of yes(1) the better thing to do would be to sleep between reads, but yes(1) is a special case.