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<h2><a name="introduction"></a>Introduction</h2>

<p>LuaLDAP is a simple interface from Lua to an LDAP client, in
fact it is a bind to <a href="http://www.openldap.org">OpenLDAP</a>
client or <a href="http://msdn2.microsoft.com/en-us/library/aa772161.aspx">ADSI</a> client</p>

<p>LuaLDAP defines one single global variable: a table called
<code>lualdap</code>. This table holds the functions used to create an
LDAP connection object.</p>

<p>A connection object offers methods to perform any operation on
the directory such as comparing values, adding new entries,
modifying attributes on existing entries, removing entries, and the
most common of all: searching. Entries are represented as Lua
tables; attributes are its fields. The attribute values can be
strings or tables of strings (used to represent multiple

<p>LuaLDAP is a bind to the
<a href="http://www.openldap.org">OpenLDAP</a> library or to <a href="http://msdn2.microsoft.com/en-us/library/aa772161.aspx">ADSI</a> library and it
depends on a previous installation of any of this libraries. You can
download OpenLDAP from the
<a href="http://www.openldap.org/software/download">OpenLDAP download</a>
page. ADSI is included on Windows 2000 or newer. Windows NT/Me/98/95
requires an <a href="http://msdn2.microsoft.com/en-us/library/aa772161.aspx">Active Directory Client Extension</a></p>
<h2><a name="building"></a>Building</h2>

LuaLDAP could be built to Lua 5.0 or to Lua 5.1.
In both cases,
the language library and headers files for the target version
must be installed properly.
LuaLDAP offers a Makefile and a separate configuration file,
which should be edited to suit your installation before runnig
The file has some definitions like paths to the external libraries,
compiler options and the like.
One important definition is the version of Lua language,
which is not obtained from the installed software.

<h2><a name="installation"></a>Installation</h2>

<p>The LuaLDAP compiled binary should be copied to a directory in your
<a href="http://www.lua.org/manual/5.1/manual.html#pdf-package.cpath">C path</a>. 
Lua 5.0 users should install <a href="http://www.keplerproject.org/compat">Compat-5.1</a> also.</p>

<p>Windows users of ADSI can use the binary versions of LuaLDAP
(<code>lualdap.dll</code>) available at
<a href="http://luaforge.net/projects/lualdap/files">LuaForge</a>.</p>

<h2><a name="attributes"></a>Representing attributes</h2>

<p>Many LDAP operations manage sets of attributes and values.
LuaLDAP provides a uniform way of representing them by using Lua
tables. The table attributes can be Lua string, a binary string (a string of
bits), or table of <em>n</em> values indexed from 1 to <em>n</em>.
Some operations have different approaches that will be explained as necessary.</p>

<p>Here is a simple example:</p>

<pre class="example">
entry = {
    an_attribute = "a value",
    other_attribute = {
        "first value of other attribute",
        "another value of other attribute",

Attribute names cannot contain the <code>'\0'</code> character.

<h2><a name="dn"></a>Distinguished names</h2>

<p>The distinguished name (DN) is the term used to identify an
entry on the directory information tree. It is formed by the
relative distinguished name (RDN) of the entry and the
distinguished name of its parent. LuaLDAP will always use a string
to represent the DN of any entry.</p>

<p>A more precise definition can be found on the LDAP
documentation. A list of some of these files can be found in
<a href="#related_docs">Related documentation</a> section.</p>

<h2><a name="initialization"></a>Initialization functions</h2>

<p>LuaLDAP provides a single way to connect to an LDAP server:</p>

    <dt><strong><code>lualdap.open_simple (hostname, who, password,
    <dd>Initializes a session with an LDAP server. This function requires a
    hostname, accordingly to the <a href="#related_docs">C LDAP API</a>
    definition (<em>"hostname contains a space-separated list of
    hostnames or dotted strings representing the IP address of hosts
    running an LDAP server to connect to. Each hostname in the list MAY
    include a port number which is separated from the host itself with
    a colon (:) character."</em>). The argument <code>who</code> should be
    the <a href="#dn">distinguished name</a> of the entry that has the
    password to be checked against the third argument,
    <code>password</code>. The optional argument <code>usetls</code> is a
    Boolean flag indicating if Transport Layer Security (TLS) should be
    Returns a connection object if the operation was successful. In case of
	error it returns <code>nil</code> followed by an error string.</dd>

<h2><a name="connection"></a>Connection objects</h2>

<p>A connection object offers methods which implement LDAP
operations. Almost all of them need a
<a href="#dn">distinguished name</a> to identify the entry on which the
operation will be executed.</p>

<p>These methods execute asynchronous operations and return a
function that should be called to obtain the results. The called
functions will return <code>true</code> indicating the success of the
operation. The only exception is the <code>compare</code> function
which can return either <code>true</code> or <code>false</code>
(as the result of the comparison) on a successful operation.</p>

<p>There are two types of errors: <em>API errors</em>, such as
wrong parameters, absent connection etc.; and <em>LDAP errors</em>,
such as malformed DN, unknown attribute etc. API errors will raise
a Lua error, while LDAP errors will be reported by the
function/method returning <code>nil</code> plus the error
message provided by the OpenLDAP client.</p>

<p>A connection object can be created by calling the <a href=
"#initialization">Initialization function</a>.</p>


    <dt><strong><code>conn:add (distinguished_name,
    <dd>Adds a new entry to the directory with the given attributes and
    values. <a name="conn_close"></a></dd>
    <dd>Closes the connection <code>conn</code>.</dd>
    <dt><strong><code>conn:compare (distinguished_name, attribute,
    <dd>Compares a value to an entry.</dd>
    <dt><strong><code>conn:delete (distinguished_name)</code></strong></dt>
    <dd>Deletes an entry from the directory.</dd>
    <dt><strong><code>conn:modify (distinguished_name,
    <dd>Changes the values of attributes in the given entry. The tables of
    operations are <a href="#attributes">tables of attributes</a>
    with the value on index <code>1</code> indicating the operation to be
    performed. The valid operations are: 
        <li><strong><code>'+'</code></strong> to add the values to the attributes</li>
        <li><strong><code>'-'</code></strong> to delete the values of the attributes</li>
        <li><strong><code>'='</code></strong> to replace the values of the attributes</li>
    Any number of tables of operations will be used in a single LDAP modify

    <dt><strong><code>conn:rename (distinguished_name, new_relative_dn,
    <dd>Changes an entry name (i.e. change its <a href="#dn">distinguished name</a>).</dd>
    <dt><strong><code>conn:search (table_of_search_parameters)</code></strong></dt>
    <dd>Performs a search operation on the directory. The parameters are
    described below:<br/><br/>
		<dd>a string or a list of attribute names to
        be retrieved (default is to retrieve all attributes).</dd>
		<dd>a Boolean value that must be either
        <em>false</em> (default) if both attribute names and values are to be
        retrieved, or <em>true</em> if only names are wanted.</dd>
		<dd>The <a href="#dn">distinguished name</a>
        of the entry at which to start the search.</dd>
		<dd>A string representing the search filter
        as described in <a href="http://www.ietf.org/rfc/rfc2254.txt">The
        String Representation of LDAP Search Filters (RFC 2254)</a>.</dd>
		<dd>A string indicating the scope of the
        search. The valid strings are: "base", "onelevel" and "subtree".
        The empty string ("") and <code>nil</code> will be treated as the
        default scope.</dd>
		<dd>The maximum number of entries to
        return (default is no limit).</dd>
		<dd>The timeout in seconds (default is no
        timeout). The precision is microseconds.</dd>
    The search method will return a <em>search iterator</em> which is a
    function that requires no arguments. The search iterator is used to
    get the search result and will return a string representing the <a
    href="#dn">distinguished name</a> and a <a href="#attributes">table
    of attributes</a> as returned by the search request.</dd>

<h2><a name="examples"></a>Example</h2>

<p>here is a some sample code that demonstrate the basic use of the library.</p>

<pre class="example">
require "lualdap"

ld = assert (lualdap.open_simple ("ldap.server",

for dn, attribs in ld:search { base = "ou=people,dc=ldap,dc=world" } do
    io.write (string.format ("\t[%s]\n", dn))
    for name, values in pairs (attribs) do
        io.write ("["..name.."] : ")
        if type (values) == "string" then
            io.write (values)
        elseif type (values) == "table" then
            local n = table.getn(values)
            for i = 1, (n-1) do
                io.write (values[i]..",")
            io.write (values[n])
        io.write ("\n")

ld:add ("mydn=newuser,ou=people,dc=ldap,dc=world", {
    objectClass = { "", "", },
    mydn = "newuser",
    abc = "qwerty",
    tel = { "123456758", "98765432", },
    givenName = "New User",

ld:modify {"mydn=newuser,ou=people,dc=ldp,dc=world",
    { '=', givenName = "New", cn = "New", sn = "User", },
    { '+', o = { "University", "College", },
           mail = "newuser@university.edu", },
    { '-', abc = true, tel = "123456758", },
    { '+', tel = "13579113", },

ld:delete ("mydn=newuser,ou=people,dc=ldp,dc=world")()


<h2><a name="related_docs"></a>Related documentation</h2>

    <li><a href="http://www.ietf.org/rfc/rfc2251.txt">Lightweight
    Directory Access Protocol (v3)</a></li>
    <li><a href="http://www.ietf.org/rfc/rfc3377.txt">LDAPv3 Technical
    <li><a href="http://www.ietf.org/rfc/rfc2254.txt">The String
    Representation of LDAP Search Filters (RFC 2254)</a></li>
    <li><a href=
    The C LDAP Application Program Interface</a></li>

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