At command for scheduling a command once

DanySK · January 7, 2021, 4:07pm

Hi,
I used to use the at command to schedule a command to execute once at a specified time. Can this tool be installed in Clear Linux?
I am not finding a suitable bundle.

btwarden · January 7, 2021, 10:11pm

I haven’t tried this, but see:

gist.github.com

https://gist.github.com/z3dm4n/2b6a6a6d795f6fc880371a0088839cb1

systemd-run-as-atd-replacement.md

```bash
$ sudo systemd --version
systemd 237
+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN -PCRE2 default-hierarchy=hybrid

$ sudo systemd-run --property=WorkingDirectory=/foo/bar --property=TimeoutSec=5min --on-active="10min" command args
Running timer as unit: run-1.timer
Will run service as unit: run-1.service

$ sudo systemctl list-timers

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DanySK · January 11, 2021, 4:54pm

Ugh… this should work, but it’s quite the hack… So no way to use atd under Clear?

btwarden · January 15, 2021, 10:55pm

It’s not a hack. It’s a standard systemd mechanism to provide the same capability without having to run a dedicated daemon all the time.

Simpler example, closer to at syntax:

$ systemd-run --user --on-calendar='14:50' sleep 30
Running timer as unit: run-r6fbf98bb0af44e608328a35e1f66e994.timer
Will run service as unit: run-r6fbf98bb0af44e608328a35e1f66e994.service
$ journalctl -u run\* --user
-- Logs begin at Mon 2021-01-11 09:06:36 PST, end at Fri 2021-01-15 14:50:30 PST. --
Jan 15 14:50:00 clr systemd[529]: Started /usr/bin/sleep 30.
Jan 15 14:50:30 clr systemd[529]: run-r6fbf98bb0af44e608328a35e1f66e994.service: Succeeded.

You could always compile and install atd in /usr/local/sbin if you prefer, though.