Hi Edward,

Thanks for your quick reply.  So can I execute grep from within a C program?  Is
there no way you know of using the usb library directly?

Cheers,
Tim

Quoting Edward <[EMAIL PROTECTED]>:

> Hello Tim,
> 
> My best bet would be to grep the /proc/bus/usb/devices file for your
> joystick device.
> 
> HTH
> Edward
> 
> ----- Original Message ----- 
> From: "Tim Arney" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, November 18, 2004 13:51
> Subject: [Linux-usb-users] Detecting unplugged device
> 
> 
> > Hi all,
> >
> > I've written a C/C++ program for controlling a robot with a USB joystick
> > under linux.  For this I'm using the joydev module.  Some of our robots
> > are quite large and fast, and a safety concern is with the joystick
> > being unplugged, then the robot should stop.  As it stands, when the
> > joystick is disconnected the "read" call blocks as though there is no
> > new data.  I could open the joystick port as non-blocking, but then
> > "read" just returns like there's no new data.  What I really need to be
> > able to do is determine whether the joystick is still attached, and I
> > figure somewhere along the chain (kernel->usb->input->joystick) someone
> > knows whether it's there, and my best guess would be the linux usb
> > driver.  So anyway, I'm essentially looking for a point in the right
> > direction as to how I might test to see if the joystick is connected
> > from my C/C++ program?
> >
> > If it helps I'm using Debian Sarge with Linux kernel 2.4.26 on an i686
> > system.
> >
> > Thanks a lot,
> > Tim
> >
> >
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