รบกวนอธิบายการใช้งาน Function: ldap_search() 1. ผมไม่เข้าใจว่าต้องใส่ข้อมูลอะไรลงไปบ้างครับ

<?php
$dn_base = 'DC=company,DC=co,DC=th';
$dn_host = 'ldap://localhost/';
$ldapusers = '[email protected]';
$ldappasswd = '30fri53';
 
// basic sequence with LDAP is connect, bind, search, interpret search
// result, close connect.
echo "Connecting to LDAP Server.. <br/>";
$ldapconn = ldap_connect("localhost", 389)
          or die("Could not connect to LDAP Server.");
		  
echo "Connect status is ".$ldapconn."<br>";

// Set some Variables
ldap_set_option($ldapconn, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_set_option($ldapconn, LDAP_OPT_REFERRALS, 0);

// Bind to LDAP Server // Binding Anonymously

$ldapbind = ldap_bind($ldapconn ,$ldapusers, $ldappasswd) or die ("Users or Password Invalid.");
echo "Connect Authentication is: ".$ldapbind."<p>";

// Search
$filter = "(&(mail=*)(pager=*))"; // CN = Common Name, SN = Surname , OU = Organization Unit

// Search surname entry
$result = ldap_search($ldapconn,$dn_base,$filter);
echo "Search result is ".$result ."<br>";
$entries = ldap_count_entries($ldapconn,$result );
echo "Number of entires returned is:".$entries."<p>";
$info = ldap_get_entries($ldapconn, $result );

for ($i=0; $i<$info["count"]; $i++){
// Variable
$userNameID = $info[$i]["pager"][0];
$userAccount = $info[$i]["samaccountname"][0];
$firstName = $info[$i]["givenname"][0];
$sureName = $info[$i]["sn"][0];
$fullName = $info[$i]["displayname"][0];
$eMail = $info[$i]["mail"][0];
$position = $info[$i]["title"][0];
$location = $info[$i]["physicaldeliveryofficename"][0];
$tel = $info[$i]["telephonenumber"][0];
echo "<option value=\"". $info[$i]["displayname"][0] ."\">".$info[$i]["pager"][0]."&nbsp;&nbsp;".$info[$i]["displayname"][0]."</option>";
}

?>