The while (<>) can be tricky when used with initial @ARGV (script parameters), but in this case, as @ARGV is the result of a glob, most of these problems are avoided. There is however something you should check: that @ARGV is not empty after the glob operation, or <> will read in the standard input. localising the change to @ARGV could avoid some trouble as well.

There's also taint mode to play it more secure.