Mac OS X Tiger in a Nutshell

Name

launchd

Synopsis

launchd [-h | -d | -s | -v | -x | command]

Introduced with Mac OS X Tiger (10.4), launchd is an automated process launcher, starting and stopping processes as needed. It’s intended as a catch-all replacement for init, /etc/rc and related scripts, SystemStarter, register_mach_bootstrap_servers, cron, loginwindow hooks run out of /etc/ttys, and watchdog (although it hasn’t yet displaced all of them). It is the first process started during the boot sequence, with a PID of 1.

Each job controlled by launchd is configured by an XML property list file located in either /System/Library/LaunchDaemons/ or /Library/LaunchDaemons/ (for system-wide daemon processes), or /System/Library/LaunchAgents/, /Library/LaunchAgents/, or ~/Library/LaunchAgents/ (for per-user processes).

launchd can be managed with the launchctl utility. Upon startup, it checks /etc/launchd.conf or ~/.launchd.conf for launchctl commands to execute, although the commands to load the daemon configuration files are currently located in /etc/rc.

Options

-d

Causes launchd to run itself as a background process.

-h

Prints a limited usage statement to standard output.

-s

Boots the system in single-user mode. This flag is used when -S is held down on startup.

-v

Boots the system in verbose mode. This flag is used when -V is held down on startup.

-x

Boots the system in safe mode. This flag is used when Shift is held ...