How to save serial monitor output as text file

I am getting my three variables on serial monitor

let A,B and C

Values of A,B and C variables are changing with time. I want to save the outputs in text file or in some other file format.

Please give the solution. urgent required for my project.
may mail also please
vijaypalece@rediffmail.com
kaithn6@gmail.com

Is Google broken? This is a frequently asked question.

Values of A,B and C variables are changing with time. I want to save the outputs in text file or in some other file format.

As you didn't specify your Arduino model I assume it's an UNO. As you didn't specify your operating system I assume it's Linux. So this is the solution to your problem:

cat /dev/ttyACM0 > $HOME/output_file.txt

Assuming some of the assumptions in Reply #2 may be incorrect another option is to use an alternative to the Serial Monitor - PuTTY is a good example - which does have the facility to save the received data to a text file.

...R