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 ...]] Many subcommands in launchctl take a specifier which indicates the target domain or service for the subcommand. This specifier may take one of the following forms: system/[service-name] Targets the system domain or a service within the system domain. The system domain manages the root Mach bootstrap and is consid- ered a privileged execution context. Anyone may read or query the system domain, but root privileges are required to make mod- ifications. user/
/[service-name] Targets the user domain for the given UID or a service within that domain. A user domain may exist independently of a logged- in user. User domains do not exist on iOS. login/ /[service-name] Targets a user-login domain or service within that domain. A user-login domain is created when the user logs in at the GUI and is identified by the audit session identifier associated with that login. If a user domain has an associated login domain, the print subcommand will display the ASID of that login domain. User-login domains do not exist on iOS. gui/ /[service-name] Another form of the login specifier. Rather than specifying a user-login domain by its ASID, this specifier targets the domain based on which user it is associated with and is generally more convenient. Note: GUI domains and user domains share many resources. For the purposes of the Mach bootstrap name lookups, they are "flat", so they share the same set of registered names. But they still have discrete sets of services. So when printing the user domain's contents, you may see many Mach bootstrap name registrations from services that exist in the GUI domain for that user, but you will not see the services themselves in that list. session/ /[service-name] Targets the session domain for the given audit session ID or a service within that domain. For more information about audit sessions, see auditon(2) and libbsm(3) pid/ /[service-name] Targets the domain for the given PID or a service within that domain. Each process on the system will have a PID domain asso- ciated with it that consists of the XPC services visible to that process which can be reached with xpc_connection_create(3). SUBCOMMANDS bootstrap | bootout domain-target [service-path service-path2 ...] | service-target Bootstraps or removes domains and services. Services may be specified as a series of paths or a service identifier. Paths may point to XPC service bundles, launchd.plist(5) s, or a directories containing a collection of either. If there were one or more errors while bootstrapping or removing a collection of services, the problematic paths will be printed with the errors that occurred. If no paths or service target are specified, these commands can either bootstrap or remove a domain specified as a domain tar- get. Some domains will implicitly bootstrap pre-defined paths as part of their creation. enable | disable service-target Enables or disables the service in the requested domain. Once a service is disabled, it cannot be loaded in the specified domain until it is once again enabled. This state persists across boots of the device. This subcommand may only target services within the system domain or user and user-login domains. uncache service-name This subcommand instructs launchd to bypass its service cache for the named service and instead read the service's configura- tion file directly from disk. launchd maintains an in-memory cache of XPC service configuration files to minimize the disk I/O. This subcommand will remove a cached entry so that develop- ers may more rapidly iterate on a service's configuration. It should not ever be used as part of production workflow. kickstart [-kp] service-target Instructs launchd to kickstart the specified service. -k If the service is already running, kill the running instance before restarting the service. -p Upon success, print the PID of the new process or the already-running process to stdout. attach [-ksx] service-target Attaches the system's debugger to the process currently backing the specified service. By default, if the service is not run- ning, this subcommand will block until the service starts. -k If the service is already running, kill the running instance. -s Force the service to start. -x Attach to xpcproxy(3) before it execs and becomes the service process. This flag is generally not useful for anyone but the launchd maintainer. debug service-target [--program ] [--guard-malloc] [--malloc-stack-logging] [--debug-libraries] [--introspection-libraries] [--NSZombie] [--32] [--stdin] [--stdout] [--stderr] [--environment] [--] [argv0 argv1 argv2 ...] Configures the next invocation of a service for debugging. This subcommand allows you to temporarily replace the main executable of the service with one at a different path, enable libgmalloc(3), set environment variables, set the argument vec- tor and more. This is a convenient alternative to editing the launchd.plist(5) for the service and then reloading it, as the additional debugging properties are cleared once the service has run once with them. --program Instructs launchd(8) to use program-path as the service's executable. --guard-malloc Turns on libgmalloc(3) for the service. --malloc-stack-logging Turns on malloc(3) stack logging for the service. --malloc-nano-allocator Turns on the malloc(3) nano allocator for the service. --debug-libraries Sets the DYLD_IMAGE_SUFFIX for the service to "_debug", which prefers the debug variants of libraries if they exist. See dyld(1) for more information. --introspection-libraries Adds /usr/lib/system/introspection to the DYLD_LIBRARY_PATH environment variable for the service. This causes the system to prefer the introspection variants of libraries if they exist. --NSZombie Enables NSZombie. --32 Runs the service in the appropriate 32-bit architec- ture. Only available on 64-bit platforms. --stdin [stdin-path] Sets the service's standard input to be stdin-path. If no file is given, uses the current terminal as the ser- vice's standard input. If stdin-path does not exist, it is created. --stdout [stdout-path] Sets the service's standard input to be stdout-path. If no file is given, uses the current terminal as the service's standard input. If stdout-path does not exist, it is created. --stderr [stderr-path] Sets the service's standard input to be stderr-path. If no file is given, uses the current terminal as the service's standard input. If stderr-path does not exist, it is created. --environment VARIABLE0=value VARIABLE1=value ... Sets the given environment variables on the service. -- argv0 argv1 ... Any arguments following the -- are given to the service as its argument vector. IMPORTANT: These arguments replace the service's default argument vector; they are not merged in any way. The first argument following -- is given as the initial (zeroth) element of the service's argument vec- tor. As with the ProgramArguments launchd.plist(5) key, you should read carefully and understand the execve(2) man page. kill signal-name | signal-number service-target Sends the specified signal to the specified service if it is running. The signal number or name (SIGTERM, SIGKILL, etc.) may be specified. blame service-target If the service is running, prints a human-readable string describing why launchd launched the service. Note that services may run for many reasons; this subcommand will only show the most proximate reason. So if a service was run due to a timer firing, this subcommand will print that reason, irrespective of whether there were messages waiting on the service's various endpoints. This subcommand is only intended for debugging and profiling use and its output should not be relied upon in pro- duction scenarios. print domain-target | service-target Prints information about the specified service or domain. Domain output includes various properties about the domain as well as a list of services and endpoints in the domain with state pertain- ing to each. Service output includes various properties of the service, including information about its origin on-disk, its current state, execution context, and last exit status. IMPORTANT: This output is NOT API in any sense at all. Do NOT rely on the structure or information emitted for ANY reason. It may change from release to release without warning. print-cache Prints the contents of the launchd service cache. print-disabled Prints the list of disabled services. plist [segment,section] Mach-O Prints the the property list embedded in the __TEXT,__info_plist segment/section of the target Mach-O or the specified seg- ment/section. procinfo pid Prints information about the execution context of the specified PID. This information includes Mach task-special ports and exception ports (and when run against a DEVELOPMENT launchd, what names the ports are advertised as in the Mach bootstrap namespace, if they are known to launchd) and audit session con- text. This subcommand is intended for diagnostic purposes only, and its output should not be relied upon in production scenar- ios. This command requires root privileges. hostinfo Prints information about the system's host-special ports, including the host-exception port. This subcommand requires root privileges. resolveport owner-pid port-name Given a PID and the name of a Mach port right in that process' port namespace, resolves that port to an endpoint name known to launchd. This subcommand requires root privileges. examine [tool arg0 arg1 @PID ...] Causes launchd to fork(2) itself for examination by a profiling tool and prints the PID of this new instance to stdout. You are responsible for killing this snapshot when it is no longer needed. Many profiling tools cannot safely examine launchd because they depend on the functionality it provides. This subcommand creates an effective snapshot of launchd that can be examined indepen- dently. Note that on Darwin platforms, fork(2) is implemented such that only the thread which called fork(2) is replicated into the new child process, so this subcommand is not useful for examining any thread other than the main event loop. This subcommand takes an optional invocation of a tool to be used on the launchd snapshot. Where you would normally give the PID of the process to be examined in the tool's invocation, instead specify the argument "@PID", and launchctl will substi- tute that argument with the PID of the launchd snapshot in its subsequent execution of the tool. If used in this form, launchctl will automatically kill the snapshot instance when the examination tool exits. This subcommand may only be used against a DEVELOPMENT launchd. config system | user parameter value Sets persistent configuration information for launchd(8) domains. Only the system domain and user domains may be config- ured. The location of the persistent storage is an implementa- tion detail, and changes to that storage should only be made through this subcommand. A reboot is required for changes made through this subcommand to take effect. Supported configuration parameters are: umask Sets the umask(2) for services within the target domain to the value specified by value. Note that this value is parsed by strtoul(3) as an octal-encoded number, so there is no need to prefix it with a leading '0'. path Sets the PATH environment variable for all services within the target domain to the string value. The string value should conform to the format outlined for the PATH environment variable in environ(7). Note that if a service specifies its own PATH, the service-spe- cific environment variable will take precedence. NOTE: This facility cannot be used to set general envi- ronment variables for all services within the domain. It is intentionally scoped to the PATH environment variable and nothing else for security reasons. reboot [system|userspace|halt|logout|apps|reroot ] Instructs launchd to begin tearing down userspace. With no argu- ment given or with the system argument given, launchd will make the reboot(2) system call when userspace has been completely torn down. With the halt argument given, launchd will make the reboot(2) system call when userspace has been completely torn down and pass the RB_HALT flag, halting the system and not ini- tiating a reboot. With the userspace argument given, launchd will re-exec itself when userspace has been torn down and bring userspace back up. This is useful for rebooting the system quickly under conditions where kernel data structures or hardware do not need to be re- initialized. With the reroot argument given, launchd will perform a userspace shutdown as with the userspace argument, but it will exec a copy of launchd from the specified mount-point. This mechanism is a light-weight way of changing boot partitions. As part of this process, launchd will make mount-point the new root partition and bring userspace up as if the kernel had designated mount-point as the root partition. IMPORTANT: This type of reboot will, in no way, affect the already-running kernel on the host. Therefore, when using this option to switch to another volume, you should only target vol- umes whose userspace stacks are compatible with the already-run- ning kernel. NOTE: As of the date of this writing, this option does not com- pletely work. With the logout argument given, launchd will tear down the caller's GUI login session in a manner similar to a logout ini- tiated from the Apple menu. The key difference is that a logout initiated through this subcommand will be much faster since it will not give apps a chance to display modal dialogs to block logout indefinitely; therefore there is data corruption risk to using this option. Only use it when you know you have no unsaved data in your running apps. With the apps argument given, launchd will terminate all apps running in the caller's GUI login session that did not come from a launchd.plist(5) on-disk. Apps like Finder, Dock and Syste- mUIServer will be unaffected. Apps are terminated in the same manner as the logout argument, and all the same caveats apply. -s When rebooting the machine (either a full reboot or userspace reboot), brings the subsequent boot session up in single-user mode. error [posix|mach|bootstrap] code Prints a human-readable string of the given error code. By default, launchctl will attempt to guess which error domain the code given belongs to. The caller may optionally specify which domain (either posix, mach, or bootstrap) to interpret the given code as an error from that subsystem. variant Prints the launchd variant currently active on the system. Pos- sible variants include RELEASE, DEVELOPMENT and DEBUG. version Prints the launchd version string.
~/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 OS X Per-user agents.
/System/Library/LaunchDaemons OS X System wide daemons.
launchd no longer loads configuration files from the network
Subcommands from the previous implementation of launchd are generally available see man launchctl for details.
launchctl will exit with status 0 if the subcommand succeeded. Otherwise, it will exit with an error code that can be given to the error subcommand to be decoded into human-readable form.
Run launchctl with sudo to see system-owned tasks.
Display the launch scripts that are currently loaded:
$ sudo launchctl list
Enable remote SSH login
$ sudo launchctl load -w /System/Library/LaunchDaemons/ssh.plist
Disable remote SSH login:
$ sudo launchctl unload -w /System/Library/LaunchDaemons/ssh.plist
“A good rule for rocket experimenters to follow is this: always assume that it will explode” ~ 'Astronautics,' issue 38, October 1937
launchctl man page - Apple.com
launchd.plist(5), launchd.conf(5), launchd(8)