Running scripts with a timeout

[senekor]

Hi!

Actually, I mostly wanted to make this post to express my appreciation. chezmoi is really amazing. I just spent the better part of this weekend migrating my heap of scripts to chezmoi. I was sceptical at first, because my scripts served me surprisingly well for a long time. But chezmoi has so many useful features which are unimaginable to reproduce with homegrown shell scripts. Thank you to everyone who contributed. twpayne especially, of course.

But I do have a little show-and-tell! My scripts run a few different kinds of updates. Most notably, dnf update which is notoriously slow. Now, I couldn't just make the update scripts onchange_, then they wouldn't run for a long time because the update command itself doesn't change. I'm quite happy with this weekly cache invalidation:

# update once a week: {{ output "date" "+%Y-%V" | trim }}

With this, I can make the script onchange_ and it won't run more than once per week. I think the documentation mentions the possiblity to include the hashes of other files for invalidation. Maybe more examples like this time-based invalidation could be added, to inspire users to find creative ways to rerun their scripts. Just a suggestion.

Again, thank you for making chezmoi!

[halostatue]

That's a very clever use of the script difference checking. For monthly scripts, this does not require a date executable: {{ now | date "2006-01" }}. The 2006-01 string is a constant format because date formatting in Go is different; it is the equivalent of %Y-%m for anything strftime-like.

There is no way to get the equivalent of %V without an external package (https://github.com/lestrrat-go/strftime would be one candidate).

[twpayne]

Here's another nice use of run_onchange_: jesse-c/dotfiles@1a96538

Here the script is re-run whenever the version of the underlying software changes.