Manpages - ldap_first_attribute.3

ldap_first_attribute, ldap_next_attribute - step through LDAP entry attributes

OpenLDAP LDAP (libldap, -lldap)

  #include <ldap.h>
  char *ldap_first_attribute(
  	LDAP *ld, LDAPMessage *entry, BerElement **berptr )
  char *ldap_next_attribute(
  	LDAP *ld, LDAPMessage *entry, BerElement *ber )
  int ldap_get_attribute_ber(
  	LDAP *ld, LDAPMessage *entry, BerElement *ber,
  	BerValue *attr, BerVarray *vals )

The ldap_first_attribute(), ldap_next_attribute() and ldap_get_attribute_ber() routines are used to step through the attributes in an LDAP entry. ldap_first_attribute() takes an entry as returned by ldap_first_entry*(3) or *ldap_next_entry*(3) and returns a pointer to character string containing the first attribute description in the entry. *ldap_next_attribute() returns the next attribute description in the entry.

It also returns, in berptr, a pointer to a BerElement it has allocated to keep track of its current position. This pointer should be passed to subsequent calls to ldap_next_attribute() and is used to effectively step through the entry’s attributes. The caller is solely responsible for freeing the BerElement pointed to by berptr when it is no longer needed by calling *ber_free*(3). When calling *ber_free*(3) in this instance, be sure the second argument is 0.

The attribute names returned are suitable for inclusion in a call to *ldap_get_values*(3) to retrieve the attribute’s values.

The ldap_get_attribute_ber() routine allows one to iterate over all attributes in-place, without allocating memory to hold text for the attribute name or its values, if requested. The use case is similar to ldap_next_attribute() except that the attribute name is returned into attr and, if vals is non-NULL, the list of values is stored there. Both point into the LDAP message and remain valid only while the entry is valid. The caller is still responsible for freeing vals with *ldap_memfree*(3), if used.

If an error occurs, NULL is returned and the ld_errno field in the ld parameter is set to indicate the error. See *ldap_error*(3) for a description of possible error codes.

The ldap_first_attribute() and ldap_next_attribute() return dynamically allocated memory that must be freed by the caller via ldap_memfree*(3). For *ldap_get_attribute_ber(), only the actual vals pointer needs to be freed with *ldap_memfree*(3), other data is accounted for as part of ber.

*ldap*(3), *ldap_first_entry*(3), *ldap_get_values*(3), *ldap_error*(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.