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<a href="ldap_open.3.html#NAME">NAME</a> | <a href="ldap_open.3.html#LIBRARY">LIBRARY</a> | <a href="ldap_open.3.html#SYNOPSIS">SYNOPSIS</a> | <a href="ldap_open.3.html#DESCRIPTION">DESCRIPTION</a> | <a href="ldap_open.3.html#ERRORS">ERRORS</a> | <a href="ldap_open.3.html#SEE_ALSO">SEE&nbsp;ALSO</a> | <a href="ldap_open.3.html#ACKNOWLEDGEMENTS">ACKNOWLEDGEMENTS</a> | <a href="ldap_open.3.html#COLOPHON">COLOPHON</a>
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<pre>
<span class="headline">LDAP_OPEN(3)              Library Functions Manual              LDAP_OPEN(3)</span>
</pre>
<h2><a id="NAME" href="ldap_open.3.html#NAME"></a>NAME  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       ldap_init,  ldap_initialize,  ldap_open - Initialize the LDAP library
       and open a connection to an LDAP server
</pre>
<h2><a id="LIBRARY" href="ldap_open.3.html#LIBRARY"></a>LIBRARY  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       OpenLDAP LDAP (libldap, -lldap)
</pre>
<h2><a id="SYNOPSIS" href="ldap_open.3.html#SYNOPSIS"></a>SYNOPSIS  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       <b>#include &lt;ldap.h&gt;</b>

       <b>LDAP *ldap_open(host, port)</b>
       char *host;
       int port;

       <b>LDAP *ldap_init(host, port)</b>
       char *host;
       int port;

       <b>int ldap_initialize(ldp, uri)</b>
       LDAP **ldp;
       char *uri;

       <b>int ldap_connect(ldp)</b>
       LDAP *ldp;

       <b>int ldap_set_urllist_proc(ld, proc, params)</b>
       LDAP *ld;
       LDAP_URLLIST_PROC *proc;
       void *params;

       <b>int (LDAP_URLLIST_PROC)(ld, urllist, url, params);</b>
       LDAP *ld;
       LDAPURLDesc **urllist;
       LDAPURLDesc **url;
       void *params;

       <b>#include &lt;ldap_pvt.h&gt;</b>

       <b>int ldap_init_fd(fd, proto, uri, ldp)</b>
       ber_socket_t fd;
       int proto;
       char *uri;
       LDAP **ldp;
</pre>
<h2><a id="DESCRIPTION" href="ldap_open.3.html#DESCRIPTION"></a>DESCRIPTION  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       <b>ldap_open() </b>opens a connection to an LDAP server and allocates an
       LDAP structure which is used to identify the connection and to
       maintain per-connection information.  <b>ldap_init() </b>allocates an LDAP
       structure but does not open an initial connection.  <b>ldap_initialize()</b>
       allocates an LDAP structure but does not open an initial connection.
       <b>ldap_init_fd() </b>allocates an LDAP structure using an existing
       connection on the provided socket.  One of these routines must be
       called before any operations are attempted.

       <b>ldap_open() </b>takes <i>host</i>, the hostname on which the LDAP server is
       running, and <i>port</i>, the port number to which to connect.  If the
       default IANA-assigned port of 389 is desired, LDAP_PORT should be
       specified for <i>port</i>.  The <i>host</i> parameter may contain a blank-separated
       list of hosts to try to connect to, and each host may optionally by
       of the form <i>host:port</i>.  If present, the <i>:port</i> overrides the <i>port</i>
       parameter to <b>ldap_open()</b>.  Upon successfully making a connection to
       an LDAP server, <b>ldap_open() </b>returns a pointer to an opaque LDAP
       structure, which should be passed to subsequent calls to <b>ldap_bind()</b>,
       <b>ldap_search()</b>, etc. Certain fields in the LDAP structure can be set
       to indicate size limit, time limit, and how aliases are handled
       during operations; read and write access to those fields must occur
       by calling <a href="ldap_get_option.3.html">ldap_get_option(3)</a> and <a href="ldap_set_option.3.html">ldap_set_option(3)</a> respectively,
       whenever possible.

       <b>ldap_init() </b>acts just like <b>ldap_open()</b>, but does not open a
       connection to the LDAP server.  The actual connection open will occur
       when the first operation is attempted.

       <b>ldap_initialize() </b>acts like <b>ldap_init()</b>, but it returns an integer
       indicating either success or the failure reason, and it allows to
       specify details for the connection in the schema portion of the URI.
       The <i>uri</i> parameter may be a comma- or whitespace-separated list of
       URIs containing only the <i>schema</i>, the <i>host</i>, and the <i>port</i> fields.
       Apart from <b>ldap</b>, other (non-standard) recognized values of the <i>schema</i>
       field are <b>ldaps </b>(LDAP over TLS), <b>ldapi </b>(LDAP over IPC), and <b>cldap</b>
       (connectionless LDAP).  If other fields are present, the behavior is
       undefined.

       At this time, <b>ldap_open() </b>and <b>ldap_init() </b>are deprecated in favor of
       <b>ldap_initialize()</b>, essentially because the latter allows to specify a
       schema in the URI and it explicitly returns an error code.

       <b>ldap_connect() </b>causes a handle created by <b>ldap_initialize() </b>to
       connect to the server. This is useful in situations where a file
       descriptor is required before a request is performed.

       <b>ldap_init_fd() </b>allows an LDAP structure to be initialized using an
       already-opened connection. The <i>proto</i> parameter should be one of
       LDAP_PROTO_TCP, LDAP_PROTO_UDP, or LDAP_PROTO_IPC for a connection
       using TCP, UDP, or IPC, respectively. The value LDAP_PROTO_EXT may
       also be specified if user-supplied sockbuf handlers are going to be
       used. Note that support for UDP is not implemented unless libldap was
       built with LDAP_CONNECTIONLESS defined.  The <i>uri</i> parameter may
       optionally be provided for informational purposes.

       <b>ldap_set_urllist_proc() </b>allows to set a function <i>proc</i> of type
       <i>LDAP_URLLIST_PROC</i> that is called when a successful connection can be
       established.  This function receives the list of URIs parsed from the
       <i>uri</i> string originally passed to <b>ldap_initialize()</b>, and the one that
       successfully connected.  The function may manipulate the URI list;
       the typical use consists in moving the successful URI to the head of
       the list, so that subsequent attempts to connect to one of the URIs
       using the same LDAP handle will try it first.  If <i>ld</i> is null, <i>proc</i> is
       set as a global parameter that is inherited by all handlers within
       the process that are created after the call to
       <b>ldap_set_urllist_proc()</b>.  By default, no <i>LDAP_URLLIST_PROC</i> is set.
       In a multithreaded environment, <b>ldap_set_urllist_proc() </b>must be
       called before any concurrent operation using the LDAP handle is
       started.

       Note: the first call into the LDAP library also initializes the
       global options for the library. As such the first call should be
       single-threaded or otherwise protected to insure that only one call
       is active. It is recommended that <b>ldap_get_option</b>() or
       <b>ldap_set_option</b>() be used in the program's main thread before any
       additional threads are created.  See <a href="ldap_get_option.3.html">ldap_get_option(3)</a>.
</pre>
<h2><a id="ERRORS" href="ldap_open.3.html#ERRORS"></a>ERRORS  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       If an error occurs, <b>ldap_open() </b>and <b>ldap_init() </b>will return NULL and
       <i><a href="errno.3.html">errno</a></i> should be set appropriately.  <b>ldap_initialize() </b>and
       <b>ldap_init_fd() </b>will directly return the LDAP code associated to the
       error (or <i>LDAP_SUCCESS</i> in case of success); <i><a href="errno.3.html">errno</a></i> should be set as
       well whenever appropriate.  <b>ldap_set_urllist_proc() </b>returns
       LDAP_OPT_ERROR on error, and LDAP_OPT_SUCCESS on success.
</pre>
<h2><a id="SEE_ALSO" href="ldap_open.3.html#SEE_ALSO"></a>SEE ALSO  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       <a href="ldap.3.html">ldap(3)</a>, <a href="ldap_bind.3.html">ldap_bind(3)</a>, <a href="ldap_get_option.3.html">ldap_get_option(3)</a>, <a href="ldap_set_option.3.html">ldap_set_option(3)</a>,
       <a href="lber-sockbuf.3.html">lber-sockbuf(3)</a>, <a href="errno.3.html">errno(3)</a>
</pre>
<h2><a id="ACKNOWLEDGEMENTS" href="ldap_open.3.html#ACKNOWLEDGEMENTS"></a>ACKNOWLEDGEMENTS  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       <b>OpenLDAP Software </b>is developed and maintained by The OpenLDAP Project
       &lt;<a href="http://www.openldap.org/">http://www.openldap.org/</a>&gt;.  <b>OpenLDAP Software </b>is derived from the
       University of Michigan LDAP 3.3 Release.
</pre>
<h2><a id="COLOPHON" href="ldap_open.3.html#COLOPHON"></a>COLOPHON  &nbsp; &nbsp; &nbsp; &nbsp; <a href="ldap_open.3.html#top_of_page"><span class="top-link">top</span></a></h2><pre>
       This page is part of the <i>OpenLDAP</i> (an open source implementation of
       the Lightweight Directory Access Protocol) project.  Information
       about the project can be found at ⟨<a href="http://www.openldap.org/">http://www.openldap.org/</a>⟩.  If you
       have a bug report for this manual page, see
       ⟨<a href="http://www.openldap.org/its/">http://www.openldap.org/its/</a>⟩.  This page was obtained from the
       project's upstream Git repository
       ⟨git://git.openldap.org/openldap.git⟩ on 2018-02-02.  (At that time,
       the date of the most recent commit that was found in the repository
       was 2018-01-30.)  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-to-
       date source for the page, or you have corrections or improvements to
       the information in this COLOPHON (which is <i>not</i> part of the original
       manual page), send a mail to man-pages@man7.org

<span class="footline">OpenLDAP LDVERSION               RELEASEDATE                    LDAP_OPEN(3)</span>
</pre>

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<p>Pages that refer to this page: 
    <a href="ldap.3.html">ldap(3)</a>,&nbsp; 
    <a href="ldap_bind.3.html">ldap_bind(3)</a>,&nbsp; 
    <a href="ldap_dup.3.html">ldap_dup(3)</a>,&nbsp; 
    <a href="../man5/slapd-meta.5.html">slapd-meta(5)</a>
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