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diff --git a/pages/user-crontabs.md b/pages/user-crontabs.md new file mode 100644 index 0000000..68da904 --- /dev/null +++ b/pages/user-crontabs.md @@ -0,0 +1,67 @@ +<!-- +title: User Crontabs +description: Using crontabs as user on tilde.institute +author: yeti +--> + +# Cron and Crontabs + +The `cron` daemon manages the global cron tables and users typically +ar not allowed to use them. + +On some systems users are allowed to have per user cron tables which +mimic the format of the global ones except for the user field. + +--> `crontab(5)` + +Showing and manipulating user crontabs is done ia an own command of +the same name. + +--> `crontab(1)` + +The main surprise could be lines in crontabs misbehaving when a `%` +occurs. `crontab(5)` should explain this. + +1. Hitchhiker 25: +(41) Deep Thought paused for a moment's reflection. +(42) "Tricky," he said finally. + + +# Test/Create your Crontab + +Use `crontab -e` and add a line like: + +``` +* * * * * >>/tmp/crontest.$USER python3%import time%print(time.time()) +``` + +After saving `cron` will execute this every minute. To disable it, +disarm it by turning it into a comment by a leading `#` or delete that +line completely. + + +# Myth + +Cron is too dumb for complex events. + +Delegate complex stuff to the command part and something to "fire" on +each last day of a month, on every even Thursday, on the 256th day of +the year, ... and much more is doable even as oneliner. + +Examples may or may not show up later. + +1. Hitchhiker 25: +(59) Scarcely pausing for breath, Vroomfondel shouted, "We don't +demand solid facts! What we demand is a total absence of solid facts. +I demand that I may or may not be Vroomfondel!" + + +# This is a stub + +...and needs to be extended by a lot. + +For now testing whether this will appear after committing is more +important than an epic collection of examples. + + +[back](/) |