Well, the first method reads a file line by line, while your second method reads one line of the file and stops. Now if you set $/ to undef then your second method would slurp in the entire file. If you're dealing with a small file that will never become large, in an environment where your process will not be running more than a single instance, the second method would be functionally ok. But it will not scale well as file size or number if instances grows.