If you want to check or set audio settings, such as the volume level or whether sound is muted, from a command line interface (CLI), aka "shell prompt", on an Apple OS X system, you can do so by using Apple's AppleScript scripting language utility, osascript.
To check the current volume setting, you can use the following command:
$ osascript -e 'output volume of (get volume settings)' 54
To check whether audio is muted, use the following command:
$ osascript -e 'output muted of (get volume settings)' false
To mute the audio so no sound will be heard:
$ osascript -e 'set volume output muted true' $ osascript -e 'output muted of (get volume settings)' true
The osascript -e 'set volume output volume x', where
x is a number between 0 and 100, can be used to change the sound
level, i.e., to make the sound softer or louder:
$ osascript -e 'output volume of (get volume settings)' 54 $ osascript -e 'set volume output volume 25' $ osascript -e 'output volume of (get volume settings)' 25
You can provide a number less than zero or more than 100 when issuing the set command, but the volume setting will never be less than 0 nor more than 100.
$ osascript -e 'set volume output volume -1' $ osascript -e 'output volume of (get volume settings)' 0 $ osascript -e 'set volume output volume -25' $ osascript -e 'output volume of (get volume settings)' 0 $ osascript -e 'set volume output volume 105' $ osascript -e 'output volume of (get volume settings)' 100
If sound is muted and you change the volume level, then it will be unmuted.
$ osascript -e 'output muted of (get volume settings)' false $ osascript -e 'set volume output muted true' $ osascript -e 'output muted of (get volume settings)' true $ osascript -e 'set volume output volume 55' $ osascript -e 'output muted of (get volume settings)' false
