#!/usr/bin/perl
use strict;
use Tie::File;
#deletes first nbytes of a file 

die "Usage: $0 file numbytes\n" unless @ARGV == 2;
my ($file, $nbytes) = @ARGV;
my $ncount=0;
my $line;

tie my @raw_data, 'Tie::File', $file , autochomp => 0 or die "Cannot Open $file: $!";

while (1){
        $line = shift @raw_data;
         while($line){
                $line = substr ($line,1);
                $ncount++;
                if($ncount >= $nbytes ){last}
        }

if ($ncount >= $nbytes ){last;}
}

unshift @raw_data,$line;
untie @raw_data;
exit 0;