1
0
mirror of git://projects.qi-hardware.com/openwrt-xburst.git synced 2024-12-25 20:55:30 +02:00
openwrt-xburst/docs/config.tex
pavlov d9219238b0 some basic cleanup, stylistic change for config files, and slight fixes
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@5455 3c298f89-4303-0410-b956-a3cf2f4a3e73
2006-11-06 23:37:55 +00:00

80 lines
2.5 KiB
TeX

\subsubsection{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:
\begin{Verbatim}
config <type> ["<name>"] # Section
option <name> "<value>" # Option
\end{Verbatim}
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.
\subsubsection{Parsing configuration files in custom scripts}
To be able to load configuration files, you need to include the common
functions with:
\begin{Verbatim}
. /etc/functions.sh
\end{Verbatim}
Then you can use \texttt{config\_load \textit{<name>}} to load config files. The function
first checks for \textit{<name>} as absolute filename and falls back to loading
it from \texttt{/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 \texttt{config\_load}
(after including \texttt{/etc/functions.sh}):
\begin{Verbatim}
config_cb() {
local type="$1"
local name="$2"
# commands to be run for every section
}
option_cb() {
# commands to be run for every option
}
\end{Verbatim}
You can also alter \texttt{option\_cb} from \texttt{config\_cb} based on the section type.
This allows you to process every single config section based on its type
individually.
\texttt{config\_cb} is run every time a new section starts (before options are being
processed). You can access the last section through the \texttt{CONFIG\_SECTION}
variable. Also an extra call to \texttt{config\_cb} (without a new section) is generated
after \texttt{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 \texttt{config\_get} command
Syntax:
\begin{Verbatim}
config_get <section> <option> # prints the value of the option
config_get <variable> <section> <option> # stores the value inside the variable
\end{Verbatim}
In busybox ash the three-option \texttt{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
\texttt{config\_set} command.
Syntax:
\begin{Verbatim}
config_set <section> <option> <value>
\end{Verbatim}