[alsa-devel] How can you tell if the speaker jack on your sound card has anything plugged into it???

[Timur Tabi]

Sean Thayne wrote:
> How would one go about getting this info? I'm trying to create a 
> monitoring tool for a specific sound card, so the driver's standardized...

First, the hardware has to detect insertion.  Then, it has to send a 
signal to the driver (either via a status register or an interrupt).

Assuming you have all that (I've never seen a sound card that provides 
this info), perhaps you can specify the output jack only when something 
is plugged in?  That is, you register the output jack when something is 
plugged in, and then deregister it when something is removed.