<?php
function get_members($group=FALSE) {
    // Active Directory server
    $ldap_host = "ad.domain";
 
    // Active Directory DN
    $ldap_dn = "CN=Users,DC=ad,DC=domain";
 
    // domain, for purposes of constructing $user
    $ldap_usr_dom = "@".$ldap_host;
 
    // Active Directory user
    $user = "jdoe";
    $password = "password";
 
    // User attributes we want to keep
    // List of User Object properties: http://www.dotnetactivedirectory.com/Understanding_LDAP_Active_Directory_User_Object_Properties.html
    $keep = array(
        "samaccountname",
        "distinguishedname"
    );
 
    // Connect and search AD
    $ldap = ldap_connect($ldap_host) or die("Could not connect to LDAP");
    ldap_bind($ldap,$user.$ldap_usr_dom,$password) or die("Could not bind to LDAP");
 
    // filter by memberOf, if group is set
    if($group) $addtl = "(memberOf=CN=$group,$ldap_dn)"; else $addtl = "";
 
    $results = ldap_search($ldap,$ldap_dn,"(&(objectClass=User)$addtl)");
    $entries = ldap_get_entries($ldap, $results);
 
    // Remove first entry (it's always blank)
    array_shift($entries);
 
    $output = array(); // Declare the output array
 
    $i = 0; // Counter
    // Build output array
    foreach($entries as $u) {
        foreach($keep as $x) $output[$i][$x] = $u[$x][0];
        $i++;
    }
 
    return $output;
}
 
print_r(get_members()); // Gets all users in 'Users'
print_r(get_members("Test Group")); // Gets all members of 'Test Group'
?>