Directory Services


For a given directory entry, the ldap_first_attribute function returns the first attribute.

PCHAR ldap_first_attribute(
  LDAP* ld,
  LDAPMessage* entry,
  BerElement** ptr


[in] The session handle.
[in] The entry whose attributes are to be stepped through, as returned by ldap_first_entry or ldap_next_entry.
[out] The address of a pointer used internally to track the current position in the entry.

Return Values

A pointer to a null-terminated string. If the function succeeds, it returns a pointer to an allocated buffer that contains the current attribute name. When there are no more attributes to step through, it returns NULL. The session error parameter in the LDAP data structure is set to 0 in either case.

If the function fails, it returns NULL and sets the session error parameter in the LDAP data structure to the LDAP error code.


Use ldap_first_attribute in conjunction with ldap_next_attribute to step through the list of attribute types returned with an entry. You can then pass these attribute names in a call to ldap_get_values to retrieve their associated values.

A call to ldap_first_attribute allocates, and returns through the ptr parameter, a pointer to a BerElement structure. Pass this pointer to ldap_next_attribute to track the current position in the list of attributes. When you have finished stepping through a list of attributes and ptr is non-NULL, free the pointer by calling ber_free( ptr, 0 ). Be aware that you must pass the second parameter as 0 (zero) in this call.

Both ldap_first_attribute and ldap_next_attribute return a pointer to an allocated buffer containing the current attribute name. Free this buffer, when no longer required, by calling ldap_memfree. Because this buffer is overwritten on the next call to either ldap_first_attribute or ldap_next_attribute, the user should make a copy of the attribute name if it must be preserved for processing.


Client: Included in Windows XP and Windows 2000 Professional.
Server: Included in Windows Server 2003 and Windows 2000 Server.
Redistributable: Requires Active Directory Client Extension on Windows NT 4.0 SP6a and Windows 95/98/Me.
Unicode: Implemented as Unicode and ANSI versions on all platforms.
Header: Declared in Winldap.h.
Library: Use Wldap32.lib.

See Also

BerElement, Functions, ber_free, ldap_first_entry, ldap_get_values, ldap_memfree, ldap_next_attribute, ldap_next_entry, Searching a Directory