#!/usr/bin/perl
use File::Find;
open (logfilefsv, '>>logfsv.txt');
$file = "C:/TestPerlFSV/Mark.txt";
open(IN, "+<$file");
#my $old = "N";
#my $new = "M";
@lines=<IN>;
print logfilefsv @lines;
foreach $file (@lines) {s/N/M/gi;}