chkconfig

The chkconfig command can also be used to activate and deactivate services. If you use the chkconfig --list command, you will see a list of system services and whether they are started (on) or stopped (off) in runlevels 0-6 (at the end of the list, you will see a section for the services managed by xinetd, which we'll discuss later in this section).

If you use chkconfig --list to query a service managed by xinetd, you will see whether the xinetd service is enabled (on) or disabled (off). For example, the following command shows that finger is enabled as an xinetd service:

$ chkconfig --list finger
finger          on

As shown above, if xinetd is running, finger is enabled.

If you use chkconfig --list to query a service in /etc/rc.d, you will see the service's settings for each runlevel, like the following:

$ chkconfig --list anacron
anacron         0:off   1:off   2:on    3:on    4:on    5:on    6:off

More importantly, chkconfig can be used to set a service to be started (or not) in a specific runlevel. For example, if we wanted to turn nscd off in runlevels 3, 4, and 5, we'd use a command like this:

chkconfig --level 345 nscd off

See the chkconfig man page for more information on how to use it.