So, I have created a text file containing the following:

10001 General Electronics 500
20001 fACEBOOK 700
10002 Twitter 400

The records are stored in a struct containing an integer id, string company and integer number of shares variables.

I want the user to enter a Id, say 20001, and the output should display the details of only that particular user and not of anyone else.

Also, I want to change number of shares of user 20001 from 700 to 600.