LaunchAgent

Location on disk of the agent

LaunchControl can be used to attempt to set the URL automatically:

LaunchControl.shared.setURL(for: agent)

Contains a unique string that identifies your daemon to launchd.

Whether the agent is enabled.

This must be true in order to load or start the agent.

Whether to enable shell globbing.

The program to be executed

Contains the arguments used to launch your daemon

This optional key is used to specify a directory to chdir(2) to before running the job.

This optional key specifies that the given path should be mapped to the job’s stdin(4), and that the contents of that file will be readable from the job’s stdin(4).

If the file does not exist, no data will be deliv- ered to the process’ stdin(4)

This optional key specifies that the given path should be mapped to the job’s stdout(4), and that any writes to the job’s stdout(4) will go to the given file.

If the file does not exist, it will be created with writable permissions and ownership reflecting the user and/or group specified as the UserName and/or GroupName, respectively (if set) and permissions reflecting the umask(2) specified by the Umask key, if set.

This optional key specifies that the given path should be mapped to the job’s stderr(4), and that any writes to the job’s stderr(4) will go to the given file.

Note that this file is opened as readable and writable as mandated by the POSIX specification for unclear reasons. If the file does not exist, it will be created with ownership reflecting the user and/or group specified as the UserName and/or GroupName, respectively (if set) and permissions reflecting the umask(2) specified by the Umask key, if set.

This optional key is used to specify additional environmental variables to be set before running the job. Each key in the dictionary is the name of an environment variable, with the corresponding value being a string representing the desired value. NOTE: Values other than strings will be ignored.

This optional key is used to control whether your job is launched once at the time the job is loaded.

This optional key causes the job to be started every N seconds.

If the system is asleep during the time of the next scheduled interval firing, that interval will be missed due to shortcomings in kqueue(3). If the job is running during an interval firing, that interval firing will like-wise be missed.

This optional key causes the job to be started every calendar interval as specified.

Missing arguments are considered to be wildcard. The semantics are similar to crontab(5) in how firing dates are specified. Multiple dictionaries may be specified in an array to schedule multiple calendar intervals.

This optional key causes the job to be started every time a filesystem is mounted.

This key does nothing if set to true. If set to false, this key is equiv- alent to specifying a true value for the KeepAlive key. This key should not be used. Please remove this key from your launchd.plist.

This key specifies whether your daemon launches on-demand or must always be running. It is recommended that you design your daemon to be launched on-demand.

This optional key causes the job to be started if any one of the listed paths are modified.

This optional key keeps the job alive as long as the directory or direc- tories specified are not empty.

This optional key specifies what value should be passed to umask(2) before running the job.

If the value specified is an integer, it must be a decimal representation of the desired umask, as property lists do not support encoding integers in octal. If a string is given, the string will be converted into an integer as per the rules described in strtoul(3), and an octal value may be specified by prefixing the string with a ‘0’. If a string that does not cleanly convert to an integer is specified, the behavior will be to set a umask(2) according to the strtoul(3) parsing rules.

This key specifies that the job should be spawned into a new security audit session rather than the default session for the context is belongs to. See auditon(2) for details.

This optional key specifies the group to run the job as.

This key is only applicable for services that are loaded into the privileged system domain. If UserName is set and GroupName is not, then the group will be set to the primary group of the user.

This optional key specifies the user to run the job as.

This key is only applicable for services that are loaded into the privileged system domain.

This optional key specifies whether initgroups(3) to initialize the group list for the job.

The default is true. This key will be ignored if the UserName key is not set. Note that for agents, the UserName key is ignored.

This optional key is used to specify a directory to chroot(2) to before running the job.

This optional key specifies whether the job can only be run once and only once.

In other words, if the job cannot be safely respawned without a full machine reboot, then set this key to be true.

This configuration file only applies to sessions of the type(s) speci- fied.

This key only applies to jobs which are agents. There are no distinct sessions in the privileged system context.

This configuration file only applies to the hosts listed with this key.

This configuration file only applies to hosts NOT listed with this key.

When a job dies, launchd kills any remaining processes with the same process group ID as the job.

Setting this key to true disables that behavior.

This key opts the job into the system’s Pressured Exit facility.

Use of this key implies EnableTransactions , and also lets the system consider process eligible for reclamation under memory pressure when it’s inac- tive. See xpc_main(3) for details. Jobs that opt into Pressured Exit will be automatically relaunched if they exit or crash while holding open transactions.

This key instructs launchd that the job uses xpc_transaction_begin(3) and xpc_transaction_end(3) to track outstanding transactions.

When a process has an outstanding transaction, it is considered active, otherwise inac- tive. A transaction is automatically created when an XPC message expect- ing a reply is received, until the reply is sent or the request message is discarded. When launchd stops an active process, it sends SIGTERM first, and then SIGKILL after a reasonable timeout. If the process is inactive, SIGKILL is sent immediately.

The amount of time launchd waits between sending the SIGTERM signal and before sending a SIGKILL signal when the job is to be stopped.

The default value is system-defined. The value zero is interpreted as infinity and should not be used, as it can stall system shutdown forever.

The presence of this key specifies that the daemon expects to be run as if it were launched from inetd.

Resource limits to be imposed on the job. These adjust variables set with setrlimit(2).

Resource limits to be imposed on the job. These adjust variables set with setrlimit(2).

The recommended idle time out (in seconds) to pass to the job.

This key never did anything interesting and is no longer implemented. Jobs seeking to exit when idle should use the EnablePressuredExit key to opt into the system mechanism for reclaiming killable jobs under memory pressure.

This key lets one override the default throttling policy imposed on jobs by launchd.

The value is in seconds, and by default, jobs will not be spawned more than once every 10 seconds. The principle behind this is that jobs should linger around just in case they are needed again in the near future. This not only reduces the latency of responses, but it encourages developers to amortize the cost of program invocation.

This optional key is used to specify Mach services to be registered with the Mach bootstrap namespace.

Each key in this dictionary should be the name of a service to be advertised. The value of the key must be a boolean and set to true or a dictionary in order for the service to be advertised.

This optional key specifies that launchd should adjust its log mask temporarily to LOG_DEBUG while dealing with this job.

This optional key specifies that launchd should launch the job in a suspended state so that a debugger can be attached to the process as early as possible (at the first instruction).

This optional key controls the behavior of timers created by the job.

By default on OS X Mavericks version 10.9 and later, timers created by launchd jobs are coalesced. Batching the firing of timers with similar deadlines improves the overall energy efficiency of the system. If this key is set to true, timers created by the job will opt into less effi- cient but more precise behavior and not be coalesced with other timers. This key may have no effect if the job’s ProcessType is not set to Interactive.

This optional key specifies whether the kernel should consider this daemon to be low priority when doing filesystem I/O.

This optional key specifies whether the kernel should consider this daemon to be low priority when doing filesystem I/O when the process is throttled with the Darwin-background classification.

This optional key specifies what nice(3) value should be applied to the daemon.

This optional key describes, at a high level, the intended purpose of the job.

The system will apply resource limits based on what kind of job it is. If left unspecified, the system will apply light resource limits to the job, throttling its CPU usage and I/O bandwidth. This classification is preferable to using the HardResourceLimits, SoftResourceLimits and Nice keys.

Instantiate a new LaunchAgent

Instantiate a new LaunchAgent

launchd.plist keys

Run launchctl start on the agent

Check the status of the job with .status()

Run launchctl stop on the agent

Check the status of the job with .status()

Run launchctl load on the agent

Check the status of the job with .status()

Run launchctl unload on the agent

Check the status of the job with .status()

Retreives the status of the LaunchAgent from launchctl