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       ldap - OpenLDAP Lightweight Directory Access Protocol API


       OpenLDAP LDAP (libldap, -lldap)


       #include <ldap.h>


       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

       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

       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 URLs.

       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


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


       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.


       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).


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

       ldap_result(3)      wait for the result from an asynchronous operation

       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


       ldap.conf(5),          slapd(8),         draft-ietf-ldapext-ldap-c-api-
       xx.txt <>


       OpenLDAP Software is developed and maintained by The  OpenLDAP  Project
       <>.    OpenLDAP   Software   is   derived  from
       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