launchd(8)						    BSD System Manager's Manual 						launchd(8)

NAME

     launchd -- System wide and per-user daemon/agent manager

DESCRIPTION

     launchd manages processes, both for the system as a whole and for individual users.

     The primary and preferred interface to launchd is via the launchctl(1) tool which (among other options) allows the user or administrator to
     load and unload jobs. Where possible, it is preferable for jobs to launch on demand based on criteria specified in their respective configu-
     ration files.

     launchd also manages XPC services that are bundled within applications and frameworks on the system.

     During boot launchd is invoked by the kernel to run as the first process on the system and to further bootstrap the rest of the system.

     You cannot invoke launchd directly.

NOTES

     On Darwin operating systems, the canonical way to launch a daemon is through launchd as opposed to traditional POSIX and POSIX-like mecha-
     nisms or mechanisms provided in earlier versions of OS X. These alternate methods should be considered deprecated and not suitable for new
     projects.

     In the launchd lexicon, a daemon is, by definition, a system-wide service of which there is one instance for all clients. An agent is a ser-
     vice that runs on a per-user basis.  Daemons should not attempt to display UI or interact directly with a user's login session. Any and all
     work that involves interacting with a user should be done through agents.

     XPC services which are marked with a ServiceType of System are functionally equivalent to daemons and run in the same environment, sharing
     the same Mach bootstrap namespace. XPC services which are marked with a ServiceType of User are equivalent to agents with the LimitLoadToSes-
     sionType key specifying the Background session and run in the same environment, sharing the same Mach bootstrap namespace. See
     launchd.plist(5) for more information about user sessions.

     On Darwin platforms, a user environment includes a specific Mach bootstrap subset, audit session and other characteristics not recognized by
     POSIX.  Therefore, making the appropriate setuid(2) and setgid(2) system calls is not sufficient to completely assume the identity for a
     given user. Running a service as a launchd agent or a per-user XPC service is the only way to run a process with a complete identity of that
     user.

FILES

     ~/Library/LaunchAgents	    Per-user agents provided by the user.
     /Library/LaunchAgents	    Per-user agents provided by the administrator.
     /Library/LaunchDaemons	    System-wide daemons provided by the administrator.
     /System/Library/LaunchAgents   Per-user agents provided by Apple.
     /System/Library/LaunchDaemons  System-wide daemons provided by Apple.

SEE ALSO

     launchctl(1), launchd.plist(5),

DEVELOPER DOCUMENTATION

     The Daemons and Services Programming Guide can be found at the following URL:

     https://developer.apple.com/library/content/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/Introduction.html

Darwin								 25 November, 2013							    Darwin