man/launchd.8

   1 .Dd 1 May, 2009
   2 .Dt launchd 8
   3 .Os Darwin
   4 .Sh NAME
   5 .Nm launchd
   6 .Nd System wide and per-user daemon/agent manager
   7 .Sh SYNOPSIS
   8 .Nm
   9 .Op Fl d
  10 .Op Fl D
  11 .Op Fl s
  12 .Op Fl S Ar SessionType
  13 .Op Ar -- command Op Ar args ...
  14 .Sh DESCRIPTION
  15 .Nm
  16 manages processes, both for the system as a whole and for individual users.
  17 The primary and preferred interface to
  18 .Nm
  19 is via the
  20 .Xr launchctl 1
  21 tool which (among other options) allows the user or administrator to load and unload jobs.
  22 Where possible, it is preferable for jobs to launch on demand based on criteria specified
  23 in their respective configuration files.
  24 .Pp
  25 During boot
  26 .Nm
  27 is invoked by the kernel to run as the first process on the system and to further bootstrap the rest of the system.
  28 .Pp
  29 You cannot invoke
  30 .Nm
  31 directly.
  32 .Sh ENVIRONMENTAL VARIABLES
  33 .Bl -tag -width -indent
  34 .It Pa LAUNCHD_SOCKET
  35 This variable is exported when invoking a command via the launchd command line. It informs launchctl how to find the correct launchd to talk to.
  36 .El
  37 .Sh NOTES
  38 In Darwin, the canonical way to launch a daemon is through
  39 .Nm launchd
  40 as opposed to more traditional mechanisms or mechanisms provided in earlier versions of Mac OS X. These alternate methods should
  41 be considered deprecated and not suitable for new projects.
  42 .Pp
  43 In the
  44 .Nm launchd
  45 lexicon, a "daemon" is, by definition, a system-wide service of which there is one instance for all clients. An "agent" is a service that runs on
  46 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
  47 with a user should be done through agents.
  48 .Pp
  49 If you wish your service to run as a certain user, in that user's environment, making it a
  50 .Nm launchd
  51 agent is the ONLY supported means of accomplishing this on Mac OS X. In other words, it is not sufficient to perform a
  52 .Xr setuid 2
  53 to become a user in the truest sense on Mac OS X.
  54 .Sh FILES
  55 .Bl -tag -width "/System/Library/LaunchDaemons" -compact
  56 .It Pa ~/Library/LaunchAgents
  57 Per-user agents provided by the user.
  58 .It Pa /Library/LaunchAgents
  59 Per-user agents provided by the administrator.
  60 .It Pa /Library/LaunchDaemons
  61 System-wide daemons provided by the administrator.
  62 .It Pa /System/Library/LaunchAgents
  63 Per-user agents provided by Mac OS X.
  64 .It Pa /System/Library/LaunchDaemons
  65 System-wide daemons provided by Mac OS X.
  66 .El
  67 .Sh SEE ALSO
  68 .Xr launchctl 1 ,
  69 .Xr launchd.plist 5 ,