cosmetic fix for docs/ prereq check
[openwrt/openwrt.git] / docs / init-scripts.tex
1 Because OpenWrt uses its own init script system, all init scripts must be installed
2 as \texttt{/etc/init.d/\textit{name}} use \texttt{/etc/rc.common} as a wrapper.
3
4 Example: \texttt{/etc/init.d/httpd}
5
6 \begin{Verbatim}
7 #!/bin/sh /etc/rc.common
8 # Copyright (C) 2006 OpenWrt.org
9
10 START=50
11 start() {
12 [ -d /www ] && httpd -p 80 -h /www -r OpenWrt
13 }
14
15 stop() {
16 killall httpd
17 }
18 \end{Verbatim}
19
20 as you can see, the script does not actually parse the command line arguments itself.
21 This is done by the wrapper script \texttt{/etc/rc.common}.
22
23 \texttt{start()} and \texttt{stop()} are the basic functions, which almost any init
24 script should provide. \texttt{start()} is called when the user runs \texttt{/etc/init.d/httpd start}
25 or (if the script is enabled and does not override this behavior) at system boot time.
26
27 Enabling and disabling init scripts is done by running \texttt{/etc/init.d/\textit{name} enable}
28 or \texttt{/etc/init.d/\textit{name} disable}. This creates or removes symbolic links to the
29 init script in \texttt{/etc/rc.d}, which is processed by \texttt{/etc/init.d/rcS} at boot time.
30
31 The order in which these scripts are run is defined in the variable \texttt{START} in the init
32 script. Changing it requires running \texttt{/etc/init.d/\textit{name} enable} again.
33
34 You can also override these standard init script functions:
35 \begin{itemize}
36 \item \texttt{boot()} \\
37 Commands to be run at boot time. Defaults to \texttt{start()}
38
39 \item \texttt{restart()} \\
40 Restart your service. Defaults to \texttt{stop(); start()}
41
42 \item \texttt{reload()} \\
43 Reload the configuration files for your service. Defaults to \texttt{restart()}
44
45 \end{itemize}
46
47 You can also add custom commands by creating the appropriate functions and referencing them
48 in the \texttt{EXTRA\_COMMANDS} variable. Helptext is added in \texttt{EXTRA\_HELP}.
49
50 Example:
51
52 \begin{Verbatim}
53 status() {
54 # print the status info
55 }
56
57 EXTRA_COMMANDS="status"
58 EXTRA_HELP=" status Print the status of the service"
59 \end{Verbatim}
60