Installation guide

4.1.1.6 Specifying Process Run Levels
Specific entries in the inittab file define the run command scripts that
are to be executed when the system enters or changes to a particular run
level. For example, the following inittab file entries specify the action to
be taken by the init program at each of the available run levels:
ss:Ss:wait:/sbin/rc0 shutdown < /dev/console > /dev/console 2>&1
s0:0:wait:/sbin/rc0 off < /dev/console > /dev/console 2>&1
s2:23:wait:/sbin/rc2 < /dev/console > /dev/console 2>&1
s3:3:wait:/sbin/rc3 < /dev/console > /dev/console 2>&1
These entries are associated with the rc directory structure and are
discussed in detail in Section 4.1.2.
4.1.1.7 Securing a Terminal Line
The /etc/securettys file indicates to the system whether terminals or
pseudoterminals can be used for root logins. To enable root logins on a
terminal line, include the pathname in the /etc/securettys file. To
enable root login on pseudoterminals, include the ptys keyword. You enable
X displays for root login by including their display name, for example :0.
By default, only the console and the X server line are set secure.
The following example of an /etc/securettys file shows root logins
enabled on the console, on the X display, on two hard-wired or LAT lines,
and on all pseudoterminals:
/dev/console
:0
/dev/tty00
/dev/tty01
ptys
4.1.2 Using the init and rc Directory Structure
The Tru64 UNIX system provides you with an initialization and run
command directory structure. The structure has four main components: the
init.d, rc0.d, rc2.d, and rc3.d directories. In addition, each of the rc
n
.d directories has a corresponding rc n run command script.
4.1.2.1 The init.d Directory
The /sbin/init.d directory contains the executable files associated with
system initialization. For example, a listing of the directory contents would
look similar to the following:
acct inetd motd preserve savecore syslog
crashdc kloadsrv named quota sendmail uucp
Customizing the System Environment 4–9