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} start}
  28 or \texttt{/etc/init.d/\textit{name} stop}. 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, which is optional and defaults to \texttt{50}. Changing it requires running
  33 \texttt{/etc/init.d/\textit{name} enable} again.
  34
  35 You can also override these standard init script functions:
  36 \begin{itemize}
  37     \item \texttt{boot()} \\
  38         Commands to be run at boot time. Defaults to \texttt{start()}
  39
  40     \item \texttt{restart()} \\
  41         Restart your service. Defaults to \texttt{stop(); start()}
  42
  43     \item \texttt{reload()} \\
  44         Reload the configuration files for your service. Defaults to \texttt{restart()}
  45
  46 \end{itemize}
  47
  48 You can also add custom commands by creating the appropriate functions and referencing them
  49 in the \texttt{EXTRA\_COMMANDS} variable. Helptext is added in \texttt{EXTRA\_HELP}.
  50
  51 Example:
  52
  53 \begin{Verbatim}
  54 status() {
  55     # print the status info
  56 }
  57
  58 EXTRA_COMMANDS="status"
  59 EXTRA_HELP="        status  Print the status of the service"
  60 \end{Verbatim}
  61