#!/usr/local/bin/perl -w
use strict;
open F,">/tmp/test" or die $!;
for (1 .. 1000) {
  syswrite F,".";
  my $s = -s F;
  warn "$s != $_" if $s != $_;
}

##</code><code>##

#!/usr/local/bin/perl -w
use strict;
open F,">/tmp/test" or die $!;
for (1 .. 1000) {
  print F ".";
  my $s = -s F;
  warn "$s != $_" if $s != $_;
}

##</code><code>##

0 != 1 at test.pl line 7.
0 != 2 at test.pl line 7.
0 != 3 at test.pl line 7.