Create unique alpha numeric string for an input string/url?

I want to create a less than or equal to 10 character unique string for an input string which c开发者_如何学编程ould be a url

http://stackoverflow.com/questions/ask

OR an alpha numeric string

programming124

but the result should be unique for every input...Is their any function or class that you use for your projects in php... Thanks...

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If you want a unique and random string, you can use the following function to create a random string:

function randString($length) {
    $charset = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
    $str = '';
    while ($length-- > 0) {
        $str .= $charset[rand() % 62];
    }
    return $str;
}

After you have generated a new string, look up your database if that string already exists. If so, repeat that step until you’ve generated a unique string. Then store that new string in the database:

do {
    $randString = randString(10);
    // look up your database if $randString already exists and store the result in $exists
} while ($exists);
// store new random string in database

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The simplest function available in php is uniqid. It is a little longer that you had mentioned, and wont work well with load balancing, but if you are doing something super simple, it should work alright.