Interfaces with launchd to load, unload daemons/agents and generally control launchd. launchctl supports taking subcommands on the command line, interactively or even redirected from standard input.
Syntax launchctl [subcommand [arguments ...]] SUBCOMMANDS load [-wF] [-S sessiontype] [-D domain] paths ... Load the specified configuration files or directories of config- uration files. Jobs that are not on-demand will be started as soon as possible. All specified jobs will be loaded before any of them are allowed to start. -w Remove the disabled key and write the configuration files back out to disk. -F Force the loading of the plist. Ignore the Disabled key. -S sessiontype Some jobs only make sense in certain contexts. This flag instructs launchctl to look for jobs in a differ- ent location when using the -D flag, and allows launchctl to restrict which jobs are loaded into which session types. Currently known session types include: Aqua, LoginWindow, Background, StandardIO and System. -D domain Look for plist(5) files ending in *.plist in the domain given. Valid domains include "system," "local," "net- work" and "all." When providing a session type, an additional domain is available for use called "user." For example, without a session type given, "-D system" would load from property list files from /Sys- tem/Library/LaunchDaemons. With a session type passed, it would load from /System/Library/LaunchAgents. unload [-w] [-S sessiontype] [-D domain] paths ... Unload the specified configuration files or directories of con- figuration files. This will also stop the job if it is running. -w Add the disabled key and write the configuration files back out to disk. -S sessiontype Some jobs only make sense in certain contexts. This flag instructs launchctl to look for jobs in a differ- ent location when using the -D flag, and allows launchctl to restrict which jobs are loaded into which session types. Currently known session types include: Aqua, LoginWindow, Background, StandardIO and System. -D domain Look for plist(5) files ending in *.plist in the domain given. Valid domains include "system," "local," "net- work" and "all." When providing a session type, an additional domain is available for use called "user." For example, without a session type given, "-D system" would load from property list files from /Sys- tem/Library/LaunchDaemons. With a session type passed, it would load from /System/Library/LaunchAgents. submit -l label [-p executable] [-o path] [-e path] -- command [args] A simple way of submitting a program to run without a configura- tion file. This mechanism also tells launchd to keep the program alive in the event of failure. -l label What unique label to assign this job to launchd. -p program What program to really execute, regardless of what fol- lows the -- in the submit sub-command. -o path Where to send the stdout of the program. -e path Where to send the stderr of the program. remove job_label Remove the job from launchd by label. start job_label Start the specified job by label. The expected use of this sub- command is for debugging and testing so that one can manually kick-start an on-demand server. stop job_label Stop the specified job by label. If a job is on-demand, launchd may immediately restart the job if launchd finds any criteria that is satisfied. Non-demand based jobs will always be restarted. Use of this subcommand is discouraged. Jobs should ideally idle timeout by themselves. list List all of the jobs loaded into launchd. setenv key value Set an environmental variable inside of launchd. unsetenv key Unset an environmental variable inside of launchd. getenv key Get an environmental variable inside of launchd. export Export all of the environmental variables of launchd for use in a shell eval statement. getrusage self | children Get the resource utilization statistics for launchd or the chil- dren of launchd. log [level loglevel] [only | mask loglevels...] Get and set the syslog(3) log level mask. The available log lev- els are: debug, info, notice, warning, error, critical, alert and emergency. limit [cpu | filesize | data | stack | core | rss | memlock | maxproc | maxfiles] [both [soft | hard]] With no arguments, this command prints all the resource limits of launchd as found via getrlimit(2). When a given resource is specified, it prints the limits for that resource. With a third argument, it sets both the hard and soft limits to that value. With four arguments, the third and forth argument represent the soft and hard limits respectively. See setrlimit(2). shutdown Tell launchd to prepare for shutdown by removing all jobs. umask [newmask] Get or optionally set the umask(2) of launchd. bslist [PID] This prints out Mach bootstrap services and their respective states. While the namespace appears flat, it is in fact hierar- chical, thus allowing for certain services to be only available to a subset of processes. The three states a service can be in are active ("A"), inactive ("I") and on-demand ("D"). bsexec PID command [args] This executes the given command in the same Mach bootstrap namespace hierachy as the given PID. help Print out a quick usage statement. ENVIRONMENTAL VARIABLES LAUNCHD_SOCKET This variable informs launchctl how to find the correct launchd to talk to. If it is missing, launchctl will use a built-in default. FILES ~/Library/LaunchAgents Per-user agents provided by the user. /Library/LaunchAgents Per-user agents provided by the adminis- trator. /Library/LaunchDaemons System wide daemons provided by the admin- istrator. /System/Library/LaunchAgents Mac OS X Per-user agents. /System/Library/LaunchDaemons Mac OS X System wide daemons.
Examples
sudo launchctl list sudo launchctl unload -w /System/Library/LaunchDaemons/finger.plist sudo launchctl load -w /System/Library/LaunchDaemons/finger.plist
Notes
Commands can be stored in $HOME/.launchd.conf or /etc/launchd.conf to be read when launchd starts.
Be very wary of extra white space when running unload commands, these can easily be interpreted by launchctl as a wildcard which will disable ALL the daemons in that folder - this will prevent the machine from booting!
If launchctl is run without any options you will enter an interactive mode (similar to ftp) interactively you can use all the normal commands listed above (load, unload, start, stop, etc.) use Control-C to exit.
Run launchctl with sudo to see system-owned tasks.
“A good rule for rocket experimenters to follow is this: always assume that it will explode” - 'Astronautics,' issue 38, October 1937
Related:
launchctl man page - Apple.com
launchd.plist(5), launchd.conf(5), launchd(8)