I'm new to shell, I want to do the following task
A shell program which accepts username and password and checks the $username and $password with a line in another file (for authentication), I know how to get the username from user but how do I check against a line in another file. say I have a file called username (which has the username) and file called password (which has the password) how do I check $username with that line and $password with that line in the file