$str="asdkjhasdkjh".chr(0)."666"; 
print "\n$str\n"; print length($str)."\n";
print "yes" if $a = substr($str,12,1); 
print "\n$a\n";

##</code><code>##

 while( length my $a =substr $z,$g,1) {

##</code><code>##

$str="asdkjhasdkjh".chr(0)."or 0 and I am 666";
print "\n$str\n";
print length($str)."\n";
 
my $g=0;
 
while( length( my $a= substr $str, $g, 1)){
  print "Character nr $g reads $a\n";
  $g++;
}
print "\n\n\tSecond run, without length\n";
$g=0;
 
while( my $a= substr $str, $g, 1){
  print "Character nr $g reads $a\n";
  $g++;
}