Is there a daemon which is not a server?

Question

It seems that a server is not necessarily running as a daemon, e.g. X server. If I am not correct, please let me know.

Is a daemon necessarily a server? Is there a daemon which is not a server? I guess there are quite a few, and I am not sure if the init processes under sysvinit and systemd are such examples.

Thanks.

Thanks. I am using Linux only, so it is hard for me to relate — Tim, Dec 19 '18 at 18:48

score 2 · Accepted Answer · edited Jan 12 '19 at 15:25

2

Anything that is performing a task without being requested to do so by a client. I.e. a daemon that is not serving clients.

I've recently played around with SSHGuard, a daemon that parses connection logs and that blocks abusive hosts. This is not a server.

The DHCP client daemon that many Unices runs variations of is not a server.

NTP is often implemented as a daemon that can function without being a server (only as a leaf node client).

edited Jan 12 '19 at 15:25

Jeff Schaller

answered Dec 19 '18 at 18:54

Kusalananda

fail2ban (similar to SSHGuard) and smartd (monitoring of S.M.A.R.T values) are two other examples that come to mind. – Zeta Dec 19 '18 at 18:56
acpid, mcelog, irqbalance, rngd, atd, and cronare all additional examples that come to mind. – Austin Hemmelgarn Dec 19 '18 at 20:15

score 0 · Answer 2 · answered Dec 19 '18 at 18:47

0

I am moving Mark's comment here

https://www.tuhs.org//cgi-bin/utree.pl?file=V7/usr/src/cmd/update.c is a daemon that is not a server.

answered Dec 19 '18 at 18:47

Tim

2 Answers2