openwrt-xburst/docs/config.txt

	== Structure of the configuration files ==

The config files are divided into sections and options/values.

Every section has a type, but does not necessarily have a name.
Every option has a name and a value and is assigned to the section
it was written under.

Syntax:

config <type> [<name>]			# Section
	option <name>	<value>		# Option


Every parameter needs to be a single string and is formatted exactly
like a parameter for a shell function. The same rules for Quoting and 
special characters also apply, as it is parsed by the shell.



	== Parsing configuration files in custom scripts ==

To be able to load configuration files, you need to include the common 
functions with:

. /etc/functions.sh

Then you can use config_load <name> to load config files. The function 
first checks for <name> as absolute filename and falls back to loading 
it from /etc/config (which is the most common way of using it).

If you want to use special callbacks for sections and/or options, you
need to define the following shell functions before running config_load
(after including /etc/functions.sh):

config_cb() {
	local type="$1"
	local name="$2"
	# commands to be run for every section
}

option_cb() {
	# commands to be run for every option
}

You can also alter option_cb from config_cb based on the section type.
This allows you to process every single config section based on its type
individually.

config_cb is run every time a new section starts (before options are being
processed). You can access the last section through the CONFIG_SECTION
variable. Also an extra call to config_cb (without a new section) is generated
after config_load is done.
That allows you to process sections both before and after all options were
processed.

You can access already processed options with the config_get command
Syntax:

config_get <section> <option>            # prints the value of the option
config_get <variable> <section> <option> # stores the value inside the variable

In busybox ash the three-option config_get is faster, because it does not
result in an extra fork, so it is the preferred way.

Additionally you can also modify or add options to sections by using the 
config_set command.

Syntax:

config_set <section> <option> <value>