RC2(ADM) UNIX System V
Name
rc2 - run commands performed for multiuser environment
Syntax
/etc/rc2
Description
This file is executed via an entry in /etc/inittab and is
responsible for those initializations that bring the system
to a ready-to-use state, traditionally state 2, called the
"multiuser" state.
The actions performed by /etc/rc2 are found in files in
several directories and are executed in a prescribed order
to ensure proper initialization. /etc/rc2 performs the
following functions in the order in which they appear:
1. Runs the script /etc/conf/bin/idmkenv. This script
sets up the new kernel environment if a new kernel has
been configured, calls idmkinit to rebuild the
/etc/inittab file, and links files to the /etc/idrc.d
and /etc/idsd.d directories to be run by /etc/rc2.
2. Runs the system setup scripts in the directory
/etc/rc2.d. Some of the scripts in this directory are
front-end scripts to run other scripts in the
subdirectories of /etc/rc.d.
3. Runs system setup scripts in the directory /etc/rc.d.
This directory exists for XENIX compatibility. It
contains subdirectories named with the numerals 0 to 9.
Each subdirectory contains scripts that perform certain
system startup functions (for example, the directory
/etc/rc.d/3 contains scripts that handle crash
recovery). All of these scripts are run by the front-
end scripts in /etc/rc2.d. Any other individual
scripts in the directory are run.
4. Runs the system setup scripts in the directory
/etc/idrc.d, which contains scripts from the driver
packages linked from /etc/conf/rc.d.
5. Runs the scripts in /etc/idsd.d, which contains
shutdown scripts linked from /etc/conf/sd.d.
6. Runs the script /etc/rc. This script exists for XENIX
compatibility. It is an empty file, but you can add
initialization commands to the file. These commands
are run last during the initialization.
The setup scripts are executed by /bin/sh in ASCII
sort-sequence order (see Files for more information). When
functions are added that need to be initialized when the
system goes multiuser, an appropriate file should be added
in /etc/rc2.d.
Other functions can be added, as required, to support the
addition of hardware and software features.
Examples
The following are prototypical files found in /etc/rc2.d.
These files are prefixed by an S and a number indicating the
execution order of the files.
MOUNTFSYS
# Set up and mount file systems
cd /
/etc/mountall
uucp
# clean-up uucp locks, status, and temporary files
rm -rf /usr/spool/locks/*
/etc/rc2 also sets certain environment variables, including
the TZ variable by reading /etc/TIMEZONE, thus establishing
the default environment for all commands that follow.
Files
Here are some hints about files in /etc/rc.d:
The order in which files are executed is important. Since
they are executed in ASCII sort-sequence order, the first
character of the file name is a sequence indicator that
helps keep the proper order. Thus, files starting with the
following characters would run accordingly:
[0-9] very early
[A-Z] early
[a-n] later
[o-z] last
Files in /etc/rc.d that begin with a dot (.) will not be
executed. This feature can be used to hide files that are
not to be executed for the time being without removing them.
The command can be used only by the super-user.
Files in /etc/rc2.d must begin with an S or a K followed by
a number and the rest of the file name. Upon entering run
level 2, files beginning with S are executed with the start
option; files beginning with K are executed with the stop
option. Files beginning with other characters are ignored.
See Also
shutdown(ADM), init(M), ``Starting and Stopping the System''
chapter of the System Administrator's Guide
(printed 2/15/90) RC2(ADM)