|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ERRORS | SEE ALSO | ACKNOWLEDGEMENTS | COLOPHON |
|
|
|
LDAP_OPEN(3) Library Functions Manual LDAP_OPEN(3)
ldap_init, ldap_initialize, ldap_open - Initialize the LDAP
library and open a connection to an LDAP server
OpenLDAP LDAP (libldap, -lldap)
#include <ldap.h>
LDAP *ldap_open(host, port)
char *host;
int port;
LDAP *ldap_init(host, port)
char *host;
int port;
int ldap_initialize(ldp, uri)
LDAP **ldp;
char *uri;
int ldap_connect(ldp)
LDAP *ldp;
int ldap_set_urllist_proc(ld, proc, params)
LDAP *ld;
LDAP_URLLIST_PROC *proc;
void *params;
int (LDAP_URLLIST_PROC)(ld, urllist, url, params);
LDAP *ld;
LDAPURLDesc **urllist;
LDAPURLDesc **url;
void *params;
#include <openldap.h>
int ldap_init_fd(fd, proto, uri, ldp)
ber_socket_t fd;
int proto;
char *uri;
LDAP **ldp;
ldap_open() 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. ldap_init() allocates an
LDAP structure but does not open an initial connection.
ldap_initialize() allocates an LDAP structure but does not open an
initial connection. ldap_init_fd() allocates an LDAP structure
using an existing connection on the provided socket. One of these
routines must be called before any operations are attempted.
ldap_open() takes host, the hostname on which the LDAP server is
running, and port, the port number to which to connect. If the
default IANA-assigned port of 389 is desired, LDAP_PORT should be
specified for port. The host parameter may contain a blank-
separated list of hosts to try to connect to, and each host may
optionally by of the form host:port. If present, the :port
overrides the port parameter to ldap_open(). Upon successfully
making a connection to an LDAP server, ldap_open() returns a
pointer to an opaque LDAP structure, which should be passed to
subsequent calls to ldap_bind(), ldap_search(), 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
ldap_get_option(3) and ldap_set_option(3) respectively, whenever
possible.
ldap_init() acts just like ldap_open(), but does not open a
connection to the LDAP server. The actual connection open will
occur when the first operation is attempted.
ldap_initialize() acts like ldap_init(), 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 uri parameter may be a comma- or whitespace-separated
list of URIs containing only the schema, the host, and the port
fields. Apart from ldap, other (non-standard) recognized values
of the schema field are ldaps (LDAP over TLS), ldapi (LDAP over
IPC), and cldap (connectionless LDAP). If other fields are
present, the behavior is undefined.
At this time, ldap_open() and ldap_init() are deprecated in favor
of ldap_initialize(), essentially because the latter allows to
specify a schema in the URI and it explicitly returns an error
code.
ldap_connect() causes a handle created by ldap_initialize() to
connect to the server. This is useful in situations where a file
descriptor is required before a request is performed.
ldap_init_fd() allows an LDAP structure to be initialized using an
already-opened connection. The proto 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 uri
parameter may optionally be provided for informational purposes.
ldap_set_urllist_proc() allows to set a function proc of type
LDAP_URLLIST_PROC that is called when a successful connection can
be established. This function receives the list of URIs parsed
from the uri string originally passed to ldap_initialize(), 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 ld is null, proc is set as a global parameter that is
inherited by all handlers within the process that are created
after the call to ldap_set_urllist_proc(). By default, no
LDAP_URLLIST_PROC is set. In a multithreaded environment,
ldap_set_urllist_proc() 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 ldap_get_option() or
ldap_set_option() be used in the program's main thread before any
additional threads are created. See ldap_get_option(3).
If an error occurs, ldap_open() and ldap_init() will return NULL
and errno should be set appropriately. ldap_initialize() and
ldap_init_fd() will directly return the LDAP code associated to
the error (or LDAP_SUCCESS in case of success); errno should be
set as well whenever appropriate. ldap_set_urllist_proc() returns
LDAP_OPT_ERROR on error, and LDAP_OPT_SUCCESS on success.
ldap(3), ldap_bind(3), ldap_get_option(3), ldap_set_option(3),
lber-sockbuf(3), errno(3)
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.
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 2025-08-11.
(At that time, the date of the most recent commit that was found
in the repository was 2025-08-05.) 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 not part of the original manual page), send a mail to
man-pages@man7.org
OpenLDAP LDVERSION RELEASEDATE LDAP_OPEN(3)
Pages that refer to this page: ldap(3), ldap_bind(3), ldap_dup(3), slapd-meta(5)
|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|