catch sda1 or /dev/scsi/host1/bus0/target0/lun0

Hello!

When I connect a usb device, dmseg tells me which special file the device is attached on.
This is sda1 or something like : /dev/scsi/host1/bus0/target0/lun0

I would like to catch this information in a script. Can anybody tell me how can i do ?
I think this is a kernel information; how can I get it ?

Thanks for your help.

FRanck