- explode: documentation ( source)
- in_array: documentation ( source)
- array_unique: documentation ( source)
<?php
$str = "cao isso pala só temp que pala vai temp aparecer temp aqui cao";
$match=array();
$return = array_unique(explode(' ', $str));
if( in_array( array('cao', 'pala', 'temp'), $return ) ){
echo 'Yes matched!';
}