#!/usr/bin/perl -w
use strict;
use diagnostics;

print "Do some regex now, shall we?\n";

print "Give me a file. Full path, please.\n";

chomp(my $filepath = <STDIN>);

print "The filename is $filepath\n";

open FILE, "$filepath" or die "Couldn't open it. Error: $!\n";

my $count = 0; # Initialize the variable, just to be safe

while (<FILE>) {
    if (/foo/) {
        $count++;
        print "$count so far.\n";
    }
}

print "Program exiting\n";