software selectable usb switch for linux

[Roger Oberholtzer]

On Fri, 7 Feb 2003 17:00:20 -0500
Joel Hammer <Joel at hammershome.com> wrote:

> I guess I don't know a hub from a switch box. From what you describe, a
> hub may be what I need. 
> Do the hubs allow software selection of the active device? What I need
> to do is break the connection to the computer from the tethered camera.
> This will allow the camera to function as a camera. Once the usb
> connection is made, the camera functions are turned but you can then
> mount the camera as a scsi device.  

Not really. all attached devices would be active from the USB point of
view. If your software is going to make a switch to select a device, it
would select the device via its handle, e.g, /proc/bus/usb/001/001
vs./proc/bus/usb/001/002. If you are making this software, look into
libusb, which makes a nice user level interface to the USB port and makes
it easier to find attached devices.

For example, your software could always use /myCamera, which is a
symbolic link to the real device. When selecting the device, what you
effectively do is change the symbolic link. There are other setups as
well. It is a matter of taste and what you are trying to accomplish. If
you are trying to shoehorn this into existing software, the symbolic link
idea would work if you can tell your software which device to use.

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