Create:
Creating a launchd configuration file may seem daunting at first but it really is easier than one first imagines it to be. There are many settings that seem confusing but they are rarely used so one can safely ignore them until one knows more about them. Begin by using the assistant to create a few and look at how they (and the Apple-supplied ones) are built and you will soon get the hang of it.This is, however, not the place to include a full tutorial and guide on how to write a configuration file for launchd but I can recommend that you first take a look at the man-pages that are linked in the Help-menu and then there are links where you will find more information:
http://developer.apple.com/macosx/launchd.html
http://www.afp548.com/article.php?story=20050620071558293&query=launchd
http://www.macgeekery.com/tips/all_about_launchd_items_and_how_to_make_one_yourself
http://data.scl.utah.edu/fmi/xsl/stream/details.xsl?-recid=200&a::v=EyaO944i72
http://www.macgeekery.com/tips/some_launchd_recipes
http://en.wikipedia.org/wiki/Launchd http://www.mactech.com/articles/mactech/Vol.21/21.06/launchd/index.html
View:
When you open Lingon you see five tabs which corresponds to the five folders where launchd looks for configuration files. The folders are:My Agents - <your home folder>/Library/LaunchAgents
Users Agents - /Library/LaunchAgents
Users Daemons - /Library/LaunchDaemons
System Agents - /System/Library/LaunchAgents
System Daemons - /System/Library/LaunchDaemons
The difference between an Agent and a Daemon is that a Daemon runs when the system starts up (and generally runs as root) and an Agent runs when someone logs in.
For each tab you see the configuration files that exists therein and its values and whether it is loaded or not. You can see more values by choosing them under Columns in the View-menu. To see more details and to make changes you can double-click on it or choose Edit. Then you can set all values and you can also choose (under the Expert tab) to see and change the plist as a text-file. Unless you know exactly what you are doing you should not change any of the Apple-supplied configuration files and not load or unload them; nor should you generally place any configuration files in the System level.
The reason that you have to authenticate as an admin when you change tabs in the main window is to be able to see if the configuration file is loaded or not. If you don't authenticate, Lingon won't know if the configuration file is loaded and it just displays a question mark in the Loaded column. And when you save or load etc. a configuration file which is not in your home folder (i.e. everything except My Agents) you need to authenticate as an admin to be able to perform that action.
Actions:
Edit - Allows you see and edit the selected launchd configuration file in a sheet, both through a graphical interface and through a text editor.Load - This tells the system that this launchd configuration file should be active and run the script according to its settings. Lingon loads it with the -w flag which means it sets the Disabled setting to false, so that it loads automatically at the next startup; if you don't want this to happen hold Option when you choose Load.
Unload - This tells the system that this launchd configuration file should not be active. Lingon unloads it with the -w flag which means it sets the Disabled setting to true, so that it won't load automatically at the next startup; if you don't want this to happen hold Option when you choose Unload.
Reload - This is just a Unload followed by a Load. This can be convenient if you've changed something in the configuration file and now want the new settings to apply.
Start - If you've e.g. configured a launchd configuration file so that it will run once every month but now you want the job to run right now, you can use Start to do that.
Stop - This stops the running job but please note that if the settings are set to start it automatically it will start again.