ls()

    boolean ls([string filter] [, string dn])
The ls() function will get a listing of the directories (DNs) under the current working directory. If filter is supplied, then the specified filter will be applied to the listing. If dn is supplied, the specified directory (DN) will be used instead of the current working directory. It will return TRUE if the search was successful, otherwise it will return FALSE. Keep in mind that a successful search does not neccessarily return any entries.

The ls() function only performs the search. You will need to use the fetch() function to retrieve the data.

For information on LDAP search filters, look at the ldap_search man page, or visit RFC 1558.

Example: 

$ldap = new LDAP();
$ldap->cd("ou=people, dc=ypass, dc=net");
$ldap->ls();
...
$attrs[$ldap->getDN()] = $ldap->fetch();
...
$ldap->ls("(objectclass=person)");
...
$attrs[$ldap->getDN()] = $ldap->fetch();
...