I only want the user name rather than the rest. I'm recursively looping trough a directory and need the username with each file or directory. I use stat to get file attributes that I need which gives me uid. Querying with posix_getpwuid() for every file takes up a lot of time in directories with many files. I came up with a caching mechanism (which I believe should be built-in). Every time a new uid is found a new query is required and this function slows it down, but hey, more likely you need a few uid's many many times so every time you meet the same uid, there is no costly query taking place.
Heres my code, feel free, etc., etc.
$arr_uname = Array();
$arr_uname[$uid] = posix_getpwuid($uid)['name'];
Works in PHP 5.3.19, under linux of course.. not tested on anything else.