Mac OS X for Unix Geeks

Startup Items

If you compile and install a daemon, you’ll probably want it to start at boot time. For example, MySQL will build out of the box on Mac OS X (you can download it from http://www.mysql.com).

A startup item is controlled by three things: a folder (such as /Library/StartupItems/MyItem), a shell script with the same name as the directory (such as MyItem), and a property list named StartupParameters.plist. The shell script and the property list must appear at the top level of the startup item’s folder. You can also create a Resources directory to hold localized resources, but this is not mandatory.

To set up the MySQL startup item, create the directory /Library/StartupItems/MySQL. Then, create two files in that directory, the startup script MySQL and the property list StartupParameters.plist. The MySQL file should be an executable since it is a shell script. After you set up these two files as directed in the following sections, MySQL will be launched at each boot.

The startup script

The startup script should be a shell script with StartService( ), StopService( ), and RestartService( ) functions. The contents of /Library/StartupItems/MySQL/MySQL are shown in Example 2-3. The function call at the bottom of the script invokes the RunService( ) function from rc.common, which in turn invokes StartService( ), StopService( ), or RestartService( ), depending on whether the script was invoked with an argument of start, stop, or restart.

Example 2-3. A MySQL startup script

#!/bin/sh ...