I think that a quick demonstration is in order. On the winblows system, do the following:

Open an MS-DOS box (command prompt) and type the following:

copy con new.txt
this is line 1
this is line 2
this is line 3
^Z
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(where ^Z represents pressing control-z)

Now in your favorite text editor, save the following as new.pl (or whatever you want) in the same location as new.txt:

open(NEW,"<","new.txt");
while ( my $line = <NEW> ) {
    chomp $line;
    process_line($line);
}
close(NEW);

sub process_line {
  my $line = shift;
  my @chars = split//,$line;
  print ord($chars[0]),$/; # print the character number of the first c
+haracter of $line
  print $line,$/;
}
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When you run new.pl, you will see that it never reaches the line with the EOF character on it.