4 ms·
Debounce in Bash
- wesleytodd 8y ago>For example it exists both in React and JavaScript There is a funny hot take in there somewhere...
- aenigmaclamo 8y agoThis seems more like a throttle rather than a debounce: https://css-tricks.com/debouncing-throttling-explained-examples/ https://css-tricks.com/debouncing-throttling-explained-examp...
- cryptonector 8y agoWhen 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.
- anothergoogler 8y agoIt's worth noting that OP's example works in any Bourne-compatible shell. I don't think `date +%s` is costly enough to warrant losing the portability.
- kadoban 8y agoI wouldn't be worried about the performance cost of using `date +%s` personally, I'd be concerned about what happens when the user or an automated process changes the system time. For example, what will happen in the debounce function if the user sets the system time backwards by a week after a limit has been set?
- anothergoogler 8y agoGood point, didn't think of that.
- cryptonector 8y agoThe title said bash. Replace "local" with "typeset" and what I wrote is compatible with KSH too -- not Bourne nor POSIX, I know, but still.
- KirinDave 8y agoGood script. I have this touchpoint problem too. Since I hate those red eraser nubs anyways, I actually disable them entirely at the xinput level. This breaks the physical right mouse button. (because Linux, ofc) but fortunately the touchpad driver replaces it. Better overall experience without any chance of pausing as the driver bounces back.
- ganonm 8y agoThe term debouncing is also used in an analogous manner for electromechanical switches and is probably the origin of the term. These switches literally 'bounce' off the contact during the first few milliseconds after the circuit is closed, rapidly opening and closing the circuit. Debouncing attempts to filter out these rapid, unwanted changes by e.g. adding a capacitor in parallel.
- deleted 8y ago[deleted]