Rename Tool (UNIX To DOS)

@ARGV is an array
- each argument passed should be a filename
- Since a local scoped variable not declared, $_ is used by default
$_ is assigned to $currentname to preserve original filename
The substitution process modifies special variable $_
- Notice we take up to the first eight characters that isn’t a period and assign that to special positional parameter \1
- $_ becomes the value of \1 with the .txt suffix appended.

#!/usr/local/bin/perl