$string = "thisisatest";
for($x=0;$x<(length($string)-1);$x++){
  $temp = $string;
  substr($temp,$x,1) = substr($string,($x+1),1);
  substr($temp,($x+1),1) = substr($string,$x,1);
  print $temp, "\n";
}


##</code><code>##

htisisatest
tihsisatest
thsiisatest
thiissatest
thissiatest
thisiastest
thisistaest
thisisaetst
thisisatset
thisisatets


##</code><code>##

($_='jjjuuusssttt annootthheer
     pppeeerrrlll haaaccckkeer')=~y/a-z//s;print;