Deamons (what is deamons)

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.Background process are called deamons and sometimes called services)

Types

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Two types:

1. Stand-alone deamon

.Location: /etc/rc.d/init.d/*

.Keeps running all the time

2. Transient deamon (service)

.Controled by super-deamon ‘xinetd’

.Location: /etc/xinetd.d/*

.Also called xniedtd-based deamons (or services)

Note: The list of /etc/rc.d/* contains runlevel specifiec shell scripts

The list of /etc/rc.d/rc3.d/* contains symbolic links

Format of symbolic links

[S/K] [XX] [SERVICE_NAME]

meaning of above formats

S- to start the service

K- to kill (ie. stop) the service

X- .No. that represents priority to start/stop the sevices

.lower no. has higer priority

Service_name- Symbolic link of the services in /etc/rc.d/init.d

/etc/rc.d

rc-> This shell executes at the time system booting as well as when the system changes its runlevel.

.This shell scripts starts/stops runlevel specific services contained in

/etc/rc.d/rcx.d/

* to switch to “n” terminal

#chrt n ie. #chrt 3

#init q to re-examine /etc/inittab