wpctl: support changing volume and mute by PID number
This MR adds a new --pid
option for the set-volume
and set-mute
sub-commands in wpctl
tool, which allows changing the volume of all nodes that were created by a client with a specific PID number.
For example, set the volume to 50% of all nodes used by a process with PID 1234:
$ wpctl set-volume --pid 1234 0.5
The same can be done to mute/unmute:
$ wpctl set-mute --pid 1234 toggle