open(my $Raw_fh, ">", "Output_Raw.txt") or file_open_error_abort("Output_Raw.txt");

# This subroutine will print a file open error message, including the filename passed to it, and terminate the program after an acknowledgement from the user.
sub file_open_error_abort
{
    my $filename = $_[0];
    say "Cannot open \"$filename\": $!.";
    print "---Press Enter to quit---";
    my $pause = <STDIN>;
    exit;
}