how to locate or find specific line word in file in linux shell command with GREP

it is often useful to locate the lines in a file that contain a word or string of characters.

lets say i have a file called myusers and i want to look for a user called lorain45. to find this user in this file, i would run this command on the linux shell to do that:

grep lorain45 myusers

the above command will display all the lines that are found with lorain45 in the myusers file

pretty easy huh!

hope this helped.