MacOS – What’s the difference between hostname’s show and the hostname on the command line

I believe I figured out the difference:

Dragging:

1. Double tap and hold to begin dragging.
2. Release the mouse.
3. Depending on the amount of time that has passed, moving the mouse will do one of the following:
   • Brief delay: moving the mouse continues the dragging, essentially behaving the exact same way as drag lock. The cycle is then repeated once you release your finger.
   • Longer delay: dragging is stopped.

Dragging & Drag Lock:

1. Double tap and hold to begin dragging.
2. Release the mouse.
3. Moving the mouse will continue dragging.
4. Tap once to stop the dragging.

It's that brief delay that was throwing me off. There doesn't seem to be any way to customize the length of this delay. One thing that does help, though, is figuring out exactly how long this delay is. One method for figuring this out is the following:

1. Drag an icon from the dock a tiny bit so that if you were to release it, it wouldn't be deleted.
2. Release the mouse.
3. Observe how long it takes for the icon to move back to its place. That is the exact amount of minimum time that you should wait when you are finished dragging something.

Launchd and Folder Actions are two vastly different concepts.

Folder Actions

Folder Actions allow you to attach actions in the form of Apple Scripts folders which get triggered if the content of the folder changes. Typical use cases are e.g.

• a folder to auto-upload photos to a website
• removal of file attributes (e.g. the "downloaded" attribute)
• triggering import into Evernote
• etc.

launchd

launchd is a system-wide feature to run and control system-level background tasks. These can be either running all the time or get triggered by specific events (e.g. a connection request coming in over IP, a changing folder, a specific point in time etc.). OS X makes heavy use of this concept for all kind of things, have a look at the names in /Library/LaunchAgents and /Library/LaunchDaemons to get an idea of functionality depending on launchd.

Because launchd is a system service running in the background all the time it can't be accessed by the user directly. To send commands to launchd, the launchctl command is used.

Answers to specific questions

• Do folder actions use launchd?

Most probably not. You can use launchd to do everything folder actions can do but at least on a level visibile to the user these are two different concepts

• Is one more efficient than the other?

No difference here, both get triggered by OS X upon special conditions.

• Is one more powerful than the other?

launchd is definitively more powerful.

• Is one used more over the other?

In a newly installed system there already is a great number of active launchd scripts but no folder actions. Because the later must be explicitely activated and configured by the user, it's probably a safe guess that launchd is used more often.