ldap(3) — Linux manual page


LDAP(3)                   Library Functions Manual                   LDAP(3)

NAME         top

       ldap - OpenLDAP Lightweight Directory Access Protocol API

LIBRARY         top

       OpenLDAP LDAP (libldap, -lldap)

SYNOPSIS         top

       #include <ldap.h>

DESCRIPTION         top

       The Lightweight Directory Access Protocol (LDAP) (RFC 4510) provides
       access to X.500 directory services.  These services may be
       stand-alone or part of a distributed directory service.  This client
       API supports LDAP over TCP (RFC 4511), LDAP over TLS/SSL, and LDAP
       over IPC (UNIX domain sockets).  This API supports SASL (RFC 4513)
       and Start TLS (RFC 4513) as well as a number of protocol extensions.
       This API is loosely based upon IETF/LDAPEXT C LDAP API draft
       specification, a (orphaned) work in progress.

       The OpenLDAP Software package includes a stand-alone server in
       slapd(8), various LDAP clients, and an LDAP client library used to
       provide programmatic access to the LDAP protocol. This man page gives
       an overview of the LDAP library routines.

       Both synchronous and asynchronous APIs are provided.  Also included
       are various routines to parse the results returned from these
       routines.  These routines are found in the -lldap library.

       The basic interaction is as follows.  A session handle is created
       using ldap_initialize(3) and set the protocol version to 3 by calling
       ldap_set_option(3).  The underlying session is established first
       operation is issued.  This would generally be a Start TLS or Bind
       operation, or a Search operation to read attributes of the Root DSE.
       A Start TLS operation is performed by calling ldap_start_tls_s(3).  A
       LDAP bind operation is performed by calling ldap_sasl_bind(3) or one
       of its friends.  A Search operation is performed by calling
       ldap_search_ext_s(3) or one of its friends.

       Subsequently, additional operations are performed by calling one of
       the synchronous or asynchronous routines (e.g., ldap_compare_ext_s(3)
       or ldap_compare_ext(3) followed by ldap_result(3)).  Results returned
       from these routines are interpreted by calling the LDAP parsing
       routines such as ldap_parse_result(3).  The LDAP association and
       underlying connection is terminated by calling ldap_unbind_ext(3).
       Errors can be interpreted by calling ldap_err2string(3).

LDAP versions         top

       This library supports version 3 of the Lightweight Directory Access
       Protocol (LDAPv3) as defined in RFC 4510.  It also supports a variant
       of version 2 of LDAP as defined by U-Mich LDAP and, to some degree,
       RFC 1777.  Version 2 (all variants) are considered obsolete.  Version
       3 should be used instead.

       For backwards compatibility reasons, the library defaults to version
       2.  Hence, all new applications (and all actively maintained
       applications) should use ldap_set_option(3) to select version 3.  The
       library manual pages assume version 3 has been selected.


       All character string input/output is expected to be/is UTF-8 encoded
       Unicode (version 3.2).

       Distinguished names (DN) (and relative distinguished names (RDN) to
       be passed to the LDAP routines should conform to RFC 4514 UTF-8
       string representation.

       Search filters to be passed to the search routines are to be
       constructed by hand and should conform to RFC 4515 UTF-8 string

       LDAP URLs to be passed to routines are expected to conform to RFC
       4516 format.  The ldap_url(3) routines can be used to work with LDAP

       LDAP controls to be passed to routines can be manipulated using the
       ldap_controls(3) routines.


       Results obtained from the search routines can be output by hand, by
       calling ldap_first_entry(3) and ldap_next_entry(3) to step through
       the entries returned, ldap_first_attribute(3) and
       ldap_next_attribute(3) to step through an entry's attributes, and
       ldap_get_values(3) to retrieve a given attribute's values.  Attribute
       values may or may not be displayable.


       Also provided are various utility routines.  The ldap_sort(3)
       routines are used to sort the entries and values returned via the
       ldap search routines.


       A number of interfaces are now considered deprecated.  For instance,
       ldap_add(3) is deprecated in favor of ldap_add_ext(3).  Deprecated
       interfaces generally remain in the library.  The macro
       LDAP_DEPRECATED can be defined to a non-zero value (e.g.,
       -DLDAP_DEPRECATED=1) when compiling program designed to use
       deprecated interfaces.  It is recommended that developers writing new
       programs, or updating old programs, avoid use of deprecated
       interfaces.  Over time, it is expected that documentation (and,
       eventually, support) for deprecated interfaces to be eliminated.

BER LIBRARY         top

       Also included in the distribution is a set of lightweight Basic
       Encoding Rules routines.  These routines are used by the LDAP library
       routines to encode and decode LDAP protocol elements using the
       (slightly simplified) Basic Encoding Rules defined by LDAP.  They are
       not normally used directly by an LDAP application program except in
       the handling of controls and extended operations.  The routines
       provide a printf and scanf-like interface, as well as lower-level
       access.  These routines are discussed in lber-decode(3),
       lber-encode(3), lber-memory(3), and lber-types(3).

INDEX         top

       ldap_initialize(3)  initialize the LDAP library without opening a
                           connection to a server

       ldap_result(3)      wait for the result from an asynchronous

       ldap_abandon_ext(3) abandon (abort) an asynchronous operation

       ldap_add_ext(3)     asynchronously add an entry

       ldap_add_ext_s(3)   synchronously add an entry

       ldap_sasl_bind(3)   asynchronously bind to the directory

       ldap_sasl_bind_s(3) synchronously bind to the directory

       ldap_unbind_ext(3)  synchronously unbind from the LDAP server and
                           close the connection

       ldap_unbind(3) and ldap_unbind_s(3) are
                           equivalent to ldap_unbind_ext(3)

       ldap_memfree(3)     dispose of memory allocated by LDAP routines.

       ldap_compare_ext(3) asynchronously compare to a directory entry

                           synchronously compare to a directory entry

       ldap_delete_ext(3)  asynchronously delete an entry

                           synchronously delete an entry

       ld_errno(3)         LDAP error indication

       ldap_errlist(3)     list of LDAP errors and their meanings

       ldap_err2string(3)  convert LDAP error indication to a string

                           asynchronously perform an arbitrary extended

                           synchronously perform an arbitrary extended

                           return first attribute name in an entry

                           return next attribute name in an entry

       ldap_first_entry(3) return first entry in a chain of search results

       ldap_next_entry(3)  return next entry in a chain of search results

                           return number of entries in a search result

       ldap_get_dn(3)      extract the DN from an entry

                           return an attribute's values with lengths

                           free memory allocated by ldap_get_values_len(3)

                           return number of values

       ldap_modify_ext(3)  asynchronously modify an entry

                           synchronously modify an entry

       ldap_mods_free(3)   free array of pointers to mod structures used by

       ldap_rename(3)      asynchronously rename an entry

       ldap_rename_s(3)    synchronously rename an entry

       ldap_msgfree(3)     free results allocated by ldap_result(3)

       ldap_msgtype(3)     return the message type of a message from

       ldap_msgid(3)       return the message id of a message from

       ldap_search_ext(3)  asynchronously search the directory

                           synchronously search the directory

       ldap_is_ldap_url(3) check a URL string to see if it is an LDAP URL

       ldap_url_parse(3)   break up an LDAP URL string into its components

                           sort a list of search results

       ldap_sort_values(3) sort a list of attribute values

                           case insensitive string comparison

SEE ALSO         top

       ldap.conf(5), slapd(8), draft-ietf-ldapext-ldap-c-api-
       xx.txt <http://www.ietf.org>


       OpenLDAP Software is developed and maintained by The OpenLDAP Project
       <http://www.openldap.org/>.  OpenLDAP Software is derived from the
       University of Michigan LDAP 3.3 Release.

       These API manual pages are loosely based upon descriptions provided
       in the IETF/LDAPEXT C LDAP API Internet Draft, a (orphaned) work in

COLOPHON         top

       This page is part of the OpenLDAP (an open source implementation of
       the Lightweight Directory Access Protocol) project.  Information
       about the project can be found at ⟨http://www.openldap.org/⟩.  If you
       have a bug report for this manual page, see
       ⟨http://www.openldap.org/its/⟩.  This page was obtained from the
       project's upstream Git repository
       ⟨https://git.openldap.org/openldap/openldap.git⟩ on 2020-11-01.  (At
       that time, the date of the most recent commit that was found in the
       repository was 2020-10-30.)  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 im‐
       provements to the information in this COLOPHON (which is not part of
       the original manual page), send a mail to man-pages@man7.org

OpenLDAP LDVERSION               RELEASEDATE                         LDAP(3)

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