A MacOS specific version of a [cron](obsidian://open?vault=enter&file=Coding%20Tips%20(Classical)%2FTerminal%20Tips%2FShells%2FComputers%20(operating%20system)%2FLinux%2FCrontab) that automates scripts and programs. 

In computing, **launchd**, a unified operating system service management framework, starts, stops and manages daemons, applications, processes, and scripts in macOS. It was introduced with Mac OS X Tiger and is licensed under the Apache License —Wikipedia. For more tips with launchd please head [here](https://www.maketecheasier.com/use-launchd-run-scripts-on-schedule-macos/). 

The official source is found [here](https://launchd.info/). 

Here are some helpful tips; 

View Services 
```
sudo launchctl list
```


without Sudo 
```
$ sudo launchctl list | grep ssh
-	0	com.openssh.sshd

$ launchctl list | grep ssh
3521	0	com.openssh.ssh-agent
```

Particular Service details 

```
$ sudo launchctl list com.openssh.sshd
{
	"Wait" = false;
	"Sockets" = {
		"Listeners" = (
			file-descriptor-object;
			file-descriptor-object;
		);
	};
	"LimitLoadToSessionType" = "System";
	"StandardErrorPath" = "/dev/null";
	"Label" = "com.openssh.sshd";
	"inetdCompatibility" = true;
	"OnDemand" = true;
	"LastExitStatus" = 0;
	"Program" = "/usr/libexec/sshd-keygen-wrapper";
	"ProgramArguments" = (
		"/usr/sbin/sshd";
		"-i";
	);
};
```


Stop and start service: 
```
sudo launchctl stop com.openssh.sshd

sudo launchctl start com.openssh.sshd
```


Service definition via print:
```
sudo launchctl print system/com.openssh.sshd
```


Loading Services

```
# load
sudo launchctl load /System/Library/LaunchDaemons/ssh.plist

# enable
sudo launchctl enable system/com.openssh.sshd

# disable
sudo launchctl disable system/com.openssh.sshd 

# unload
sudo launchctl unload /System/Library/LaunchDaemons/ssh.plist
```

via [Rakesh](https://rakhesh.com/mac/macos-launchctl-commands/)

---
### More things to test with Launchd

- Check that the script is an executable 
```
```bash
chmod +x /Library/Scripts/com.apple.restart.sh
```

- enable the full path to the script 
```
```bash
#!/bin/bash
/sbin/shutdown -r now
```

Found by 
```
which shutdown 

output: 

/sbin/shutdown
```

Ensure that the output is ACII file and not RTF or Pages or MS-Word
```
file /Library/Scripts/com.apple.restart.sh

output: 
/Library/Scripts/com.apple.restart.sh: Bourne-Again shell script text executable, ASCII text

```

Create a redirect for outputs: 
```
<key>StandardOutPath</key>
<string>/tmp/com.apple.restart.stdout</string>
<key>StandardErrorPath</key>
<string>/tmp/com.apple.restart.stderr</string>
```

A great launchd blog [post on  here too. ](https://ellismin.com/2020/03/launchd-1/)