LDAP_OPEN(3)						     Library Functions Manual						      LDAP_OPEN(3)

NAME

       ldap_init, ldap_initialize, ldap_open - Initialize the LDAP library and open a connection to an LDAP server

LIBRARY

       OpenLDAP LDAP (libldap, -lldap)

SYNOPSIS

       #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;

       #include <ldap_pvt.h>

       int ldap_init_fd(fd, proto, uri, ldp)
       ber_socket_t fd;
       int proto;
       char *uri;
       LDAP **ldp;

DESCRIPTION

       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 spec-
       ify 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_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.

       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).

ERRORS

       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.

SEE ALSO

       ldap(3), ldap_bind(3), ldap_get_option(3), ldap_set_option(3), lber-sockbuf(3), errno(3)

ACKNOWLEDGEMENTS

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

OpenLDAP 2.4.21 						    2009/12/20							      LDAP_OPEN(3)