3.2.1 Specifying Search Parameters

Searching is performed using the LdapConnection.Search function. When you perform an LDAPsearch, you need to specify the following basic parameters:

filter = " ( " filtercomp " ) "
filtercomp = and / or / not / item

and = "&" filterlist
   filterlist = 1*filter

or = "|" filterlist
   filterlist = 1*filter

not = "!" filterlist
   filterlist = 1*filter

item = simple / present / substring / extensible

simple = attr filtertype value
   attr =  name | name;binary
   filtertype = equal / approx / greater / less
   value = data valid for the attribute's syntax

equal = "="
approx = "~="
greater = ">="
less = "<="

present = attr "=*"
   attr =  name | name;binary

substing = attr "=" [initial] any [final]
   attr =  name | name;binary
   initial = value
   any = "*" *(value "*")
   final = value

extensible = attr [":dn"] [":" matchingrule] ":="value
            / [":dn] ":" matchingrule ":=" value
            / matchingrule = name | OID

3.2.2 Getting Search Results

Each result returned by the Search function is stored in a MessageQueue which can be retrieved either in a synchronous way using LdapSearchResults class or in an asynchronous way using LdapSearchQueue class.

The C# code snippet below shows how to do a synchronous and asynchronous search in a LDAP server:

string searchBase = "ou=development,o=acme";
int searchScope = LdapConnection.SCOPE_BASE; 
string searchFilter = "(title=engineer)";

Searching the Directory - Asynchronous

// C# Library namespace
using Novell.Directory.Ldap;

// Creating an LdapConnection instance 
LdapConnection ldapConn= new LdapConnection();

//Connect function will create a socket connection to the server
ldapConn.Connect(ldapHost,ldapPort);

//Bind function will Bind the user object Credentials to theServer
ldapConn.Bind(userDN,userPasswd);

// Searches in the Marketing container and return all child entries
just below this container i.e Single level search

LdapSearchQueue queue=ldapConn.Search (searchBase,
LdapConnection.SCOPE_ONE, searchFilter,null,false,(LdapSearchQueue)
null,(LdapSearchConstraints)null );
LdapMessage message;
while ((message = queue.getResponse()) !=null)
{ 
   if (message is LdapSearchResult)
   {
          LdapEntry entry = (LdapSearchResult) message.Entry;
          System.Console.Out.WriteLine("\n" + entry.DN);
          System.Console.Out.WriteLine("\tAttributes: ");

          // Get the attribute set of the entry
          LdapAttributeSet attributeSet = entry.getAttributeSet();
          System.Collections.IEnumerator ienum =
attributeSet.GetEnumerator();
       
         // Parse through the attribute set to get the attributes and
the corresponding values
          while(ienum.MoveNext())
          {
                 LdapAttribute attribute=(LdapAttribute)ienum.Current;
                 string attributeName =attribute.Name; 
                 string attributeVal = attribute.StringValue;
                 Console.WriteLine( attributeName + "value:" +
attributeVal);}}
          }

   //Procced 

   //While all the required entries are parsed, disconnect   
   ldapConn.Disconnect();

Searching the Directory - Synchronous

// C# Library namespace
using Novell.Directory.Ldap;

// Creating an LdapConnection instance 
LdapConnection ldapConn= new LdapConnection();

//Connect function will create a socket connection to the server
ldapConn.Connect(ldapHost,ldapPort);

//Bind function will bind the user object Credentials to the Server
ldapConn.Bind(userDN,userPasswd);

// Searches in the Marketing container and return all child entries
just below this container i.e. Single level search

LdapSearchResults
lsc=ldapConn.Search("ou=Marketing,o=Sales",LdapConnection.SCOPE_ONE,"
objectClass=*",null,false);
while (lsc.hasMore())
{
   LdapEntry nextEntry = null;
   try 
   {
       nextEntry = lsc.next(); 
   } catch(LdapException e) 
     { 
         Console.WriteLine("Error: " + e.LdapErrorMessage);
         //Exception is thrown, go for next entry
         continue; 
     } 

Console.WriteLine("\n" + nextEntry.DN);

// Get the attribute set of the entry
LdapAttributeSet attributeSet = nextEntry.getAttributeSet();
System.Collections.IEnumerator ienum = attributeSet.GetEnumerator();

// Parse through the attribute set to get the attributes and the
corresponding values
while(ienum.MoveNext())
{ 
   LdapAttribute attribute=(LdapAttribute)ienum.Current;
   string attributeName = attribute.Name; 
   string attributeVal = attribute.StringValue;
   Console.WriteLine( attributeName + "value:" + attributeVal);}
}

//Procced 

//While all the entries are parsed, disconnect   
ldapConn.Disconnect();