[linux] Aanpassen groep van /dev/bus/usb/001/001 i.v.m. xsane

[Cecil Westerhof]

In het verleden kon ik zonder (belangrijke) problemen xsane gebruiken.
Ik moest gisteren wat dingen scannen, maar dat lukte niet. (Ik neem
aan dat het te maken heeft met mijn overgang naar openSUSE 11.3. Zeker
weten doe ik dat niet. Ik scan niet zo heel erg vaak.) Opstarten van
xsane leverde de volgende foutmeldingen op:
    libusb couldn't open USB device /dev/bus/usb/001/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/001/003: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/001/005: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/001/007: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/002/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/002/002: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/003/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/004/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/004/002: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/005/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/006/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/007/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/008/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/001/003: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/001/005: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/001/007: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/002/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/002/002: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/003/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/004/001: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/004/002: Permission denied.
    libusb requires write access to USB device nodes.
    libusb couldn't open USB device /dev/bus/usb/005/001: Permission denied.
    libusb requires write access to USB device nodes.

Dit heb ik opgelost door het volgende commando te geven:
    chgrp users /dev/bus/usb/001/001

Hiermee veranderde:
    crw-rw-r-- 1 root root  189, 0 Sep  1 10:29 /dev/bus/usb/001/001
in:
    crw-rw-r-- 1 root users 189, 0 Sep  1 10:29 /dev/bus/usb/001/001


Hierdoor werd de eerste foutmelding niet meer gegenereerd (de rest nog
wel) en werkte xsane weer zoals het moet.

Een paar vragen:
- Iemand een idee waarom het probleem is ontstaan?
- Is mijn oplossing oké, of kan het problemen opleveren?
- Moet ik dezelfde actie bij de andere devices doen, of moet ik ergens
anders iets aanpassen?

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof