rc.config(4)

/etc/rc.config

The file /etc/rc.config is a script that sources all of the /etc/rc.config.d/* scripts, and also sources /etc/TIMEZONE. To read the configuration definitions, only this file need be sourced. This file is sourced by /sbin/rc whenever it is run, such as when the init command is run to transition between run states. Each file that exists in /etc/rc.config.d is sourced, without regard to which startup scripts are to be executed.

/etc/rc.config.d

The configuration information is structured as a directory of files, rather than as a single file containing the same information. This allows developers to create and manage their own configuration files here, without the complications of shared ownership and access of a common file.

/etc/rc.config.d/* Files

This is where files containing configuration variable assignments are located.

Configuration scripts must be written to be read by the POSIX shell, and not the Bourne shell, ksh, or csh. In some cases, these files must also be read and possibly modified by sd control scripts or the sam program. See sd(4) and sam(1M). For this reason, each variable definition must appear on a separate line, with the syntax:

No trailing comments may appear on a variable definition line. Comment statements must be on separate lines, with the # comment character in column one. This example shows the required syntax for configuration files:

Configuration variables may be declared as array parameters when describing multiple instances of the variable configuration. For example, a system may contain two network interfaces, each having a unique IP address and subnet mask (see ifconfig(1M)). An example of such a declaration is as follows:

Note that there must be no requirements on the order of the files sourced. This means configuration files must not refer to variables defined in other configuration files, since there is no guarantee that the variable being referenced is currently defined. There is no protection against environment variable namespace collision in these configuration files. Programmers must take care to avoid such problems.

/etc/TIMEZONE

The file /etc/TIMEZONE contains the definition of the TZ environment variable. This file is required by POSIX. It is sourced by /sbin/rc at the same time the /etc/rc.config.d/* files are sourced.