A GUID (globally unique identifier) is a bigger, badder version of this type of ID number. You may see the term UUID tossed about (universally unique identifier), a nitpicky word for those whose numbers are unique not only within the globe, but throughout the entire universe. - http://guid.us/GUID/PHP

git-graph.rb

PHP

Its easy to make GUIDs in PHP. Below is clean code using windows COM to get GUIDs. When the PHP creates GUIDs or UUIDs they are V4 guids.

$guid = com_create_guid();
echo $guid;

If you are not a on windows based platform you can roll this code for making GUIDs in PHP:

function getGUID(){
    if (function_exists('com_create_guid')){
        return com_create_guid();
    }else{
        mt_srand((double)microtime()*10000);//optional for php 4.2.0 and up.
        $charid = strtoupper(md5(uniqid(rand(), true)));
        $hyphen = chr(45);// "-"
        $uuid = chr(123)// "{"
            .substr($charid, 0, 8).$hyphen
            .substr($charid, 8, 4).$hyphen
            .substr($charid,12, 4).$hyphen
            .substr($charid,16, 4).$hyphen
            .substr($charid,20,12)
            .chr(125);// "}"
        return $uuid;
    }
}

To use the above functon:

$GUID = getGUID();
echo $GUID;