Hi Jonathan, Yea, that's a very fragile part of the scripts (relying on the details of the tree structure in /sys). If anyone has a better suggestion, it's welcome! What it's looking for is the devnum of the common hub that the keyboard, mouse, and display are all sitting off of. With that, you'll see ls -lR /dev/usbseat showing kbd, mouse, display clustered together. Guessing from your output, if you back up one more directory on those two lines (more more ../ ), I'd guess you'll have it. Thanks, Bernie <div class="gmail_quote">On Tue, Sep 15, 2009 at 8:47 AM, Jonathan D. Proulx <<a href="mailto:jon@csail.mit.edu">jon@csail.mit.edu</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi Bernie, Thanks for writing up the multiseat stuff! After a couple of issue with finding missing execute bits and a script I forgot to copy into play I think I've narrowed the actual problem to: run_program: '/bin/cat /sys//class/input/input12/mouse2/../../../../../devnum' run_program: '/bin/cat' (stderr) '/bin/cat: /sys//class/input/input12/mouse2/../../../../../devnum: No such file or directory' presumably it wants to get to one of these: [jon@kvas multiseat-bits]$ find /sys/ -name devnum /sys/devices/pci0000:00/0000:00:1a.0/usb1/devnum /sys/devices/pci0000:00/0000:00:1a.0/usb1/1-1/devnum /sys/devices/pci0000:00/0000:00:1a.1/usb2/devnum /sys/devices/pci0000:00/0000:00:1a.2/usb3/devnum /sys/devices/pci0000:00/0000:00:1a.7/usb4/devnum /sys/devices/pci0000:00/0000:00:1a.7/usb4/4-2/devnum /sys/devices/pci0000:00/0000:00:1a.7/usb4/4-2/4-2.2/devnum /sys/devices/pci0000:00/0000:00:1a.7/usb4/4-2/4-2.4/devnum /sys/devices/pci0000:00/0000:00:1d.0/usb5/devnum /sys/devices/pci0000:00/0000:00:1d.1/usb6/devnum /sys/devices/pci0000:00/0000:00:1d.2/usb7/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-3/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-4/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-4/8-4.3/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-4/8-4.3/8-4.3.1/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-4/8-4.3/8-4.3.3/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-4/8-4.4/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-5/devnum /sys/devices/pci0000:00/0000:00:1d.7/usb8/8-5/8-5.2/devnum But can't figure any number of ../ paths that will get there /sys//class/input/input12/mouse2/device/../devnum does exist but is apparently the wrong thing, switching the rules to use that gives me: ls -R /dev/usbseat/ /dev/usbseat/: 17 18 3 /dev/usbseat/17: mouse /dev/usbseat/18: keyboard /dev/usbseat/3: display So the rules are getting triggered, but I'm not sure what devnums we want to pull -Jon </blockquote></div>