Your program is doing exactly what you tell it to do. It reads the first line of input from the file, and if it doesn't match, the program exits. That's obviously not what you want it to do, so do something else. Don't exit until either there is a match or you've read the entire file.

Also, you use lexical 'my' variables in one place and package '$main::' package variables in another for no good reason. 'use strict' is a good habit to get into when you're just learning, and if you want globals, put them in a 'use vars' at the top of the script. It'll catch typos in variable names and can save lots of debugging time, and save you from typing 'main::' on all the variables (since 'use vars' declares them in the current package, you don't have to specify the package). If you think this script is too short to bother with 'use strict', then there's no point in the 'my' and 'main::' either.