LDAPOPEN(3)                                                      LDAPOPEN(3)



NAME
       ldapinit,  ldapopen  - Initialize the LDAP library and open a connec-
       tion to an LDAP server

LIBRARY
       OpenLDAP LDAP (libldap, -lldap)

SYNOPSIS
       ##include <>

       LDAP **ldapopen(host,, port)
       char *host;
       int port;

       LDAP **ldapinit(host,, port)
       char *host;
       int port;

DESCRIPTION
       ldapopen() 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.  ldapinit() allocates an  LDAP  structure  but
       does not open an initial connection.  One of these two routines must be
       called before any operations are attempted.

       ldapopen() takes host, the hostname on which the LDAP server  is  run-
       ning,  and  port,  the port number to which to connect.  If the default
       IANA-assigned port of 389 is desired, LDAPORT 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
       ldapopen().  Upon successfully making a connection to an LDAP  server,
       ldapopen()  returns  a  pointer  to an LDAP structure (defined below),
       which  should  be  passed   to   subsequent   calls   to   ldapbind(),
       ldapsearch(),  etc. Certain fields in the LDAP structure can be set to
       indicate size limit, time limit, and how  aliases  are  handled  during
       operations.  See  for more details.

            typedef struct ldap {
                 /* ... other stuff you should not mess with ... */
                 char      ldlberoptions;
                 int       ldderef;
            #define LDAPDEREFNEVER 0
            #define LDAPDEREFSEARCHING  1
            #define LDAPDEREFINDING    2
            #define LDAPDEREFALWAYS     3
                 int       ldtimelimit;
                 int       ldsizelimit;
            #define LDAPNOLIMIT         0
                 int       lderrno;
                 char      *lderror;
                 char      *ldmatched;
                 int       ldrefhoplimit;
                 unsigned long  ldoptions;
            #define LDAPOPTREFERALS      0x00000002 /* set by default */
            #define LDAPOPTRESTART 0x00000004
                 /* ... other stuff you should not mess with ... */
            } LDAP;

       ldapinit()  acts just like ldapopen(), but does not open a connection
       to the LDAP server.  The actual connection open  will  occur  when  the
       first  operation is attempted.  At this time, ldapinit() is preferred.
       ldapopen() will be depreciated in a later release.

ERORS
       If an error occurs, these routines will return NUL and errno should be
       set appropriately.

OPTIONS
       Options  that affect a particular LDAP instance may be set by modifying
       the ldoptions field in the LDAP  structure.   This  field  is  set  to
       LDAPOPTREFERALS  in  ldapopen()  and  ldapinit(),, which causes the
       library to automatically follow referrals to other servers that may  be
       returned in response to an LDAP operation.

       The other supported option is LDAPOPTRESTART, which if set will cause
       the LDAP library to restart the select(2) system call when it is inter-
       rupted by the system (i.e., errno is set to EINTR).  This option is not
       supported on the Macintosh and under MS-DOS.

       An option can be turned off by clearing  the  appropriate  bit  in  the
       ldoptions field.

NOTES
       There  are  other  elements  in  the LDAP structure that you should not
       change. You should not make any assumptions about the order of elements
       in the LDAP structure.

SEE ALSO
       ldap(3), ldapbind(3), errno(3)

ACKNOWLEDGEMENTS
       OpenLDAP   is   developed   and  maintained  by  The  OpenLDAP  Project
       (http:/www.openldap.org/).  OpenLDAP is  derived  from  University  of
       Michigan LDAP 3.3 Release.



OpenLDAP 2.2.19                   2004/11/26                      LDAPOPEN(3)