Generating confirmation code for an email confirmation

Question

Using PHP, what are some ways to generate a random confirmation code that can be stored in a DB and be used for email confirmation? I can\'t for the life of me think of a wa

Answer 1

Decided I need something a little more robust and added functionality. So this is what I came up with.

/**
 * Hash Gen 
 * @author Kyle Coots
 * @version    1.0
 * Allow you to create a unique hash with a maximum value of 32.
 * Hash Gen uses phps substr, md5, uniqid, and rand to generate a unique 
 * id or hash and allow you to have some added functionality.
 * 
 * @see subtr()
 * @see md5()
 * @see uniqid()
 * @see rand()
 *  
 * You can also supply a hash to be prefixed or appened
 * to the hash. hash[optional] is by default appened to the hash 
 * unless the param prefix[optional] is set to prefix[true].     
 * 
 * @param start[optional]
 * @param end[optional]
 * @param hash[optional]
 * @param prefix bool[optional]
 * 
 * @return string a unique string max[32] character
 */
function hash_gen($start = null, $end = 0, $hash = FALSE, $prefix = FALSE){

    // start IS set NO hash
    if( isset($start, $end) && ($hash == FALSE) ){

        $md_hash = substr(md5(uniqid(rand(), true)), $start, $end);
        $new_hash = $md_hash;

    }else //start IS set WITH hash NOT prefixing
    if( isset($start, $end) && ($hash != FALSE) && ($prefix == FALSE) ){

        $md_hash = substr(md5(uniqid(rand(), true)), $start, $end);
        $new_hash = $md_hash.$hash;

    }else //start NOT set WITH hash NOT prefixing 
    if( !isset($start, $end) && ($hash != FALSE) && ($prefix == FALSE) ){

        $md_hash = md5(uniqid(rand(), true));
        $new_hash = $md_hash.$hash;

    }else //start IS set WITH hash IS prefixing 
    if( isset($start, $end) && ($hash != FALSE) && ($prefix == TRUE) ){

        $md_hash = substr(md5(uniqid(rand(), true)), $start, $end);
        $new_hash = $hash.$md_hash;

    }else //start NOT set WITH hash IS prefixing
    if( !isset($start, $end) && ($hash != FALSE) && ($prefix == TRUE) ){

        $md_hash = md5(uniqid(rand(), true));
        $new_hash = $hash.$md_hash;

    }else{

        $new_hash = md5(uniqid(rand(), true));

    }

    return $new_hash;

 }