#!/usr/bin/perl
print"Content-type:text/html\n\n";   
$txt="PERL";
$i=0;
while ($i < length($txt)) { 
  print substr($txt,$i,1),"<br>";
  $i++;
}
print "<hr>";
for ($i=0; $i< length($txt); $i++) {
  print substr($txt,$i,1),"<br>";
}
print "<hr>";
for $i (0..length($txt)-1){
  push @txtr,substr($txt,$i,1);
}
foreach $r(@txtr){
  print "$r<br>";
}
print "<hr>";
$i = 0;
do {
  print substr($txt,$i,1),"<br>";
  $i++;
} until $i eq length($txt);