Returns the result entry identifier for the first entry on success and FALSE on error.
Entries in the LDAP result are read sequentially using the ldap_first_entry() and ldap_next_entry() functions. ldap_first_entry() returns the entry identifier for first entry in the result. This entry identifier is then supplied to ldap_next_entry() routine to get successive entries from the result.
See also ldap_get_entries().