The Redis PHP module gives access to the same commands as the Redis CLI client so it is quite straightforward to use.
The syntax is as follow:
// Creates two new keys:
$redis->set('mykey-1', 123);
$redis->set('mykey-2', 'abcd');
// Gets one key (prints '123')
var_dump($redis->get('mykey-1'));
// Gets all keys starting with 'my-key-'
// (prints '123', 'abcd')
var_dump($redis->keys('mykey-*'));