how to generate shortest possible string in php?

Question

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How to code a URL shortener?

How to generate shortest possible string (the way e.g. bit.ly is doing this)?

This is a very general question... Be more specific ;-). – thedom Jan 30 '11 at 12:51 — thedom, Jan 30 '11 at 12:51
$shortestPossibleString = ''; – Mark Baker Jan 30 '11 at 12:53 — Mark Baker, Jan 30 '11 at 12:53
Are you asking for a hashing algorithm? – Tim Post Jan 30 '11 at 12:54 — Tim Post, Jan 30 '11 at 12:54

score 0 · Answer 1 · answered Jan 30 '11 at 13:03

Well you would have to make random string and then check if you allredy have it in your database! Here i write you a example how to. Btw. this is just a quick one. There are much more things that could be checked to speed it up!

$cl=2;
$cr=0;
$n="";
while(!$e){
  if($cr>500){$cr=0;$cl++;}
  $n=genRandomString($cl);
  $checker = mysql_query("select count(*) as haveit from table where thestring='".$n."'");
  $xa = mysql_fetch_array($checker);
  if($xa['haveit']==0){$e=1;}
  $cr++;
}

function genRandomString($len){
    $length = $len;
    $characters = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    $string = '';
    for ($p = 0; $p < $length; $p++) {
        $string .= $characters[mt_rand(0, strlen($characters))];
    }
    return $string;
}

This is just to give you idea how to do it! This have to be optimized a little! :D

how to generate shortest possible string in php?

1 Answers1