Sams Teach Yourself Perl in 21 Days, Second Edition

Input from Files with while Loops and <>

Over the last three days, you've seen a number of examples that read input from the keyboard using <STDIN>. You've also used the standard input file handle in both a scalar and list context, so at this point you should know the difference between input in a scalar context (line by line) and input in a list context (read until end-of-file).

Getting input from the keyboard, however, is pretty tedious for any amount of input more than a few lines. That statistics script we worked on yesterday proves it—entering more than a couple of numbers into the script takes a long time, and if we want to just add to the existing data, we have to reenter it all each time.

Ideally, then, we'd store the data in a separate ...