Questions around /sys & udev

[E001754]

Hello,

Before udev, we were using the /dev folder. I was relatively happy, but suddenly, when I upgrade my Gentoo to kernel 2.6.14, I discovered that this was replaced by /sys folder (but there is still the /dev folder for compatibility reasons).

So, here are the questions :
- Were can I find documentation on how to use the /sys folder instead of /dev ? (I didn't find anything in Gentoo doc, but perhaps did I look too fast ??)
- Why should I use /sys instead of /dev ?

In fact, I got a little problem (but very little). I have a digital camera which acts as a USB mass storage.
If I plug the camera alone, the camera appears as /dev/sdb
If I plug my printer, which contains a card reader, the card reader becomes /dev/sdb and by the way, the digital camera is /dev/sdc.

If I use /sys, will it be possible to have definitely the camera known as /dev/sdc, whatever could be the state (pluged or unpluged) of my printer ???

Thanks for your help.

[adsmith]

Not quite.
/sys and /dev are for different purposes.
/dev is still used by udev for all devices, but now it's created on-the-fly.

/sys is something like the /proc file system, which keeps track of various system information. The /dev directory is still for all devices you access.

[widan]

[E001754]

Thanks for your answers, it's more clear now.