how can i start the screensaver (and lock the screen) from the os x terminal?

Question

Is there a way to start the screensaver (and lock the screen) from a bash script?

Answer 1

Have you tried this?

/System/Library/Frameworks/ScreenSaver.framework/Resources/ScreenSaverEngine.app/Contents/MacOS/ScreenSaverEngine

Update for macOS High Sierra:

/System/Library/CoreServices/ScreenSaverEngine.app/Contents/MacOS/ScreenSaverEngine

Answer 2

Here is a bash script that does exactly what you are asking for: maclock

It is called from the command line as follows:

maclock

Under the covers it calls:

open -a ScreenSaverEngine

It can also be used to mute the system, or put the display to sleep:

maclock --mute --display