I adopted this instruction although not labored for me personally. I simply wanna install and config cakephp during my new Mac laptop Professional which explains why I am attempted to relabel my php.ini.default to php.ini. Before that, I'd not a problem in interacting between my MySQL and Mac pre-installed PHP.

Wrong with that instruction. ( specifically "Getting MySQL and PHP to speakInch part )

BTW it isn't permission problem or mysql.sock location I believe. I checked them.

Help me. Thanks

First let's wait and watch when we could possibly get a far more detailed error message than "Error hooking up to mysql".
What is the creation of:

error_reporting(E_ALL); ini_set('display_errors', 1);
echo 'mysql extension: ', extension_loaded('mysql') ? 'ok' : 'NOT ok', "<br />\n";
echo 'mysql_connect: ', function_exists('mysql_connect') ? 'ok' : 'NOT ok', "<br />\n";
mysql_connect('fill in', 'the right', 'values here') or die(mysql_error());