ARDUINO CANNOT RECOGNIZE THE SERIAL PORT

HOW DO I GET THE ARDUINO TO RECOGNIZE THE SERIAL PORT USING LINUX? I HAVE THE UNO R3

What kind of disro are you useing? Eg. Ubuntu, Fedora, redhat, Debian
And what version

Your statement is backwards. You are wondering how Linux recognizes the emulated serial port?

First, you caps lock seems to be broken.

Open a terminal, connect arduino, type 'sudo dmesg'
You will se a line at the end looking something like

25028.93171 cdc_acm 2-1.8:1.0: ttyACM0: USB ACM device

So, in my case the serial port is called /dev/ttyACM0

I use openSUSE 12.3.10, and my arduino is the UNO. I have the same problem above. When I select: "tools> serial port" , it does not allow to be selected. what should I do to solve this problem.