2013-12-02, 08:18
Everything under /sys is generally only writable by root, so you need to use sudo or in some other way run the command as root.
Also be aware that everything under /sys is NOT a real file, it is created by the kernel to give a file system like * interface to certain kernel facilities. Similar to /proc. Sometimes you therefore get unexpected behaviour. You can (as root) write to it, but the effects are not always what you expect.
Oh and of course in a different kernel, your pnp/00:08 node may be a completely different device.
* in unix, everything is a file - the main exception in linux being network devices like eth0 and lo.
Also be aware that everything under /sys is NOT a real file, it is created by the kernel to give a file system like * interface to certain kernel facilities. Similar to /proc. Sometimes you therefore get unexpected behaviour. You can (as root) write to it, but the effects are not always what you expect.
Oh and of course in a different kernel, your pnp/00:08 node may be a completely different device.
* in unix, everything is a file - the main exception in linux being network devices like eth0 and lo.