I'm trying to get a "daemon" (really just a script, more than a background process) to activate when a file (specifically, /dev/console) changes owner (i.e., when another user takes control of the console) on MacOS Mojave.
I'm trying to do this by running launchd and having it watch that file for changes. I tried doing this with WatchPaths, as in the script below, but apparently that only notices "creating, removing and writing to this file", not chown. Script is below, along with more background story. Any ideas on how to do this?
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>LoginScripts.blockyoutube.sh</string>
<key>ProgramArguments</key>
<array>
<string>/Users/Shared/blockyoutube.sh</string>
</array>
<key>WatchPaths</key>
<array>
<string>/dev/console</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>StandardOutPath</key>
<string>/var/log/blockyoutube.log</string>
<key>StandardErrorPath</key>
<string>/var/log/blockyoutube.log</string>
</dict>
</plist>
Backstory
What I'm really trying to do is block my kids' accounts from YouTube ... but not my wife's account on the same computer. In theory System Preferences->Parental Controls should do this fine — which it does ... until someone launches Chrome and it backchannels the DNS lookup to 8.8.8.8.
The only way I've figured out to work around this is to not let the OS DNS query fail, so Chrome doesn't attempt to do that, so I'm updating /etc/hosts to point to localhost and flushing DNS whenever the console owner changes. Other solutions to this backstory are also welcome, but it does seem that there should be a way to make launchd watch for change in owner of a file.
Related
I have a number of launch agents I've written over the years to automate some simple tasks, like rsyncing my music and photos from my laptop to my NAS. Recently I've noticed that they have stopped running daily like they used to. Instead, they're only running when I log in. Here's a sample launchagent:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.mwheinz.backup_photos</string>
<key>Program</key>
<string>/Users/michaelheinz/bin/backup_photos</string>
<key>StartInterval</key>
<integer>86400</integer>
<key>RunAtLoad</key>
<true/>
</dict>
</plist>
When I run them with "debug" it says they are configured to run "at launch":
~ » sudo launchctl debug gui/501/com.mwheinz.backup_books
Password:
Service configured for next launch.
Any suggestions? One thing I've noticed is that launchd now insists I refer to my agents as "gui/501/<label>" instead of just "<label>".
Okay - I figured it out. The problem for me was that the syntax for the plists changed at some point. This syntax:
Program
/Users/michaelheinz/bin/backup_books
StartInterval
became this syntax:
ProgramArguments
/Users/michaelheinz/bin/backup_books
StartInterval
I changed all my plists and they started working again.
I am trying to add an application as login item for all users by creating an launchd plist and copying it in /Library/LaunchAgents and also by loading it.
Plist is
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.testapp.UserAgent</string>
<key>ProgramArguments</key>
<array>
<string>/Applications/TestAgent.app/Contents/MacOS/TestAgent</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>KeepAlive</key>
<false/>
</dict>
</plist>
RunAtLoad will launch the application at every login.
It is working for me when I login in to all different user accounts in my machine but if I quit it manually then also it is launching by itself.
How can I make it to launch only once for each login and if I quit it then it should not be launched by itself.
The best resource to know how to use launchd, the daemon that launches processes on macOS is here:
https://www.launchd.info
In here, it is well explained what other settings you can use apart from RunAtLoad or together with it.
For example, in your case, you could use the key KeepAlive as follows:
<key>KeepAlive</key>
<dict>
<key>SuccessfulExit</key>
<false/>
</dict>
This would only relaunch your process if it exited with a code different than 0, which normally denotes some abnormal situation or error. If the exit is normal then your process will not be relaunched by launchd.
Check the tab Configuration on this site to know which other configurations you could use.
I'd like to run an app I created via Automator every 5 minutes, so I placed the following com.user.wilson.plist file in this folder:
/Library/LaunchAgents
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.user.wilson</string>
<key>ProgramArguments</key>
<array>
<string>/usr/bin/open</string>
<string>-a</string>
<string>/Users/paul/Documents/Wilson/Script/mt-wilson-background_app</string>
</array>
<key>StartInterval</key>
<integer>300</integer>
</dict>
</plist>
Then, I loaded it using the following command in the terminal:
launchctl load Library/LaunchAgents/com.user.wilson.plist
but for some reason, the app never runs.
I can, however, successfully run the app using this command:
/usr/bin/open -a /Users/paul/Documents/Wilson/Script/mt-wilson-background_app
Any ideas why the .plist file won't do what I'm expecting it to?
In order to see what's going wrong, you can add a log file in your plist like this:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.user.wilson</string>
<key>StandardErrorPath</key>
<string>/Users/paul/Documents/Wilson/Script/err.log</string>
<key>ProgramArguments</key>
<array>
<string>/usr/bin/open</string>
<string>-a</string>
<string>/Users/paul/Documents/Wilson/Script/mt-wilson-background_app</string>
</array>
<key>StartInterval</key>
<integer>300</integer>
</dict>
</plist>
Note: For the modifications to take effect, unload and load again:
launchctl unload Library/LaunchAgents/com.user.wilson.plist
launchctl load Library/LaunchAgents/com.user.wilson.plist
Typically, if the err.log says it can't find your app, it means it's a permission issue.
I would suggest you try to move your app from /Users/paul/Documents/Wilson/Script/mt-wilson-background_app to /Users/paul/Documents/mt-wilson-background_app
Then update your plist accordingly, unload an reload your plist, is it working better now?
I ran into nearly the exact same problem. I finally (FINALLY!!!) found a cure that worked for me.
Originally, the broken version of the .plist launch agent that wouldn't run no matter what I tried was in /Library/LaunchAgents. Moving the agent to /Users/[me]/LaunchAgents eliminated the "Application Not Running" error.
It seems counterintuitive since the root agent should be able to run everything from any location, but I can only guess that AppleScript's check to see if an app is running or not is user account-dependent somehow. I'm betting there's something you can add to the AppleScript to actually fix this the "right" way, but this works well enough for me, so I'm taking the win.
I’m trying to make a launch agent that starts a Python script. It should run when there’s a network connection but it doesn’t do that. launchctl list says it’s loaded:
launchctl list | grep test.Flopsey.DiscordMusicBot
- 0 test.Flopsey.DiscordMusicBot
When I start it with launchctl start test.Flopsey.DiscordMusicBot it works fine. The .plist file (which is stored under ~/Library/LaunchAgents) looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>test.Flopsey.DiscordMusicBot</string>
<key>ProgramArguments</key>
<array>
<string>/Library/Frameworks/Python.framework/Versions/3.5/bin/python3.5</string>
<string>/path/to/MusicBot/run.py</string>
</array>
<key>EnvironmentVariables</key>
<dict>
<key>PATH</key>
<string>/bin:/usr/bin:/usr/local/bin</string>
</dict>
<key>StandardOutPath</key>
<string>/path/to/MusicBot/log.log</string>
<key>StandardErrorPath</key>
<string>/path/to/MusicBot/log.log</string>
<key>WorkingDirectory</key>
<string>/path/to/MusicBot</string>
<key>KeepAlive</key>
<dict>
<key>NetworkState</key>
<true/>
</dict>
</dict>
</plist>
I’m new to launchd and I followed this tutorial. I think the solution to my problem is very basic but I have no idea what it could be. I’ve also made another similar agent and it works fine (unlike the music bot it’s only one file).
Update
Thanks to #LCC’s comment I realised that using NetworkState doesn’t work anymore on OS X 10.10 and higher. Since the script exits when it can’t connect to the Internet I can just set KeepAlive to <true/> and set up a ThrottleInterval so launchd restarts the script after a cooldown if it couldn’t connect.
it looks like it loads but has a status of 1 when using launchctl list
and using launchctl start ... it says No such Process...
i have it saved in /Users/IMG/Library/LaunchAgents.
The sh script runs fine.
the logging doesn't show anything - no file created..
I am very new to plist so please forgive ignorance.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.IMG.shed</string>
<key>ProgramArguments</key>
<array>
<string>/Users/IMG/2012/Dropbox/Dev_2012/Java/sh_IMG.sh</string>
</array>
<key>StandardOutPath</key>
<string>myjob.log</string>
<key>StandardErrorPath</key>
<string>myjob.log</string>
<key>Debug</key>
<true/>
<key>RunAtLoad</key>
<true/>
<key>StartInterval</key>
<integer>60</integer>
</dict>
</plist>
The first thing I thought was the process does not have permission to create the standard output log file (although I imagine the default value for working directory for a personal agent would be the user's home directory). There is an optional property key for WorkingDirectory - perhaps try setting that to see if anything changes.
Reference: Launchd.plist man page
In XCode 4.5.2, under the Product menu, you need to pick Edit Scheme. You will see the manage schemes box appear with several schemes. One of these is called Run <ProjectName>. Click the checkbox next to Working Directory Use custom working directory and point that to the path where your plist is at.
This elaborates on the answer given by unhillbilly. So thanks unhillbilly for steering me towards the Working Directory.