On Wed, Jun 26, 2019 at 12:18:25PM +0200, Andras Korn wrote: > > > I just wrote this script: > > > https://gist.github.com/akorn/51ee2fe7d36fa139723c851d87e56096 and thought > > > it might be a good addition to moreutils. > > > > > > It caches the stdout, stderr and exit status of arbitrary commands for a > > > configurable length of time, returning data from cache on subsequent > > > invocations if the cache is still fresh. > > > > thanks for your suggestion; I think it's quite an interesting idea! > > And you made me curious: which commands are you running through > > 'runcached'? All programs I thought of have their basic functionality > > based on side-effects as file system or network access. > > Examples: > > * I have a Makefile to regenerate the data.cdb file for tinydns whenever > any of the local source files changed. Part of the process is downloading > some remote DNS zones with axfr-get, which is relatively slow. The remote > zones don't change frequently; I don't want to download them each time, > but I do want to download them at least once every eight hours or so. So > I run axfr-get via runcached, with a cache ttl of 8 hours. > > * Some monitoring systems like Zabbix and Munin need to run data-gathering > stuff that is time-consuming; it sometimes happens that several plugins > need to run the same thing, but extract different data from its output. > Instead of having separate, ad-hoc caching in all such plugins, it's > better to have a generic caching solution. > > * When looking for space hogs in the filesystem, I often use > 'du -hscx * .* | sort -h' and then dig down further. Without runcached > I would have to either save the output separately, or keep opening new > sessions in screen(1), or wait for the same output to be generated again, > when I go up to the higher level directory again. With runcached, `du` is > cheap the 2nd time, and I don't care if the numbers are slightly off when > they come from the cache. > > * Same for ad-hoc log analysis sessions: I may grep through a bunch of > logs, then grep for something else, then grep for the same thing again. > With runcached, I don't need to worry about saving output I may need > again, because runcached does it for me.
* Oh, and ldapsearch. I have some scheduled scripts that each do something to members of the same group; before, I had an ad-hoc cache for group members, but with runcached I can just re-run ldapsearch with the same arguments and get cached results. András -- Win any staring contest: slowly go in for a kiss without breaking eye contact.
