ldap_first_attribute(3)

1LDAP_FIRST_ATTRIBUTE(3)    Library Functions Manual    LDAP_FIRST_ATTRIBUTE(3)
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NAME

6       ldap_first_attribute, ldap_next_attribute - step through LDAP entry at‐
7       tributes
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LIBRARY

10       OpenLDAP LDAP (libldap, -lldap)
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SYNOPSIS

13       #include <ldap.h>
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15       char *ldap_first_attribute(
16            LDAP *ld, LDAPMessage *entry, BerElement **berptr )
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18       char *ldap_next_attribute(
19            LDAP *ld, LDAPMessage *entry, BerElement *ber )
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21       int ldap_get_attribute_ber(
22            LDAP *ld, LDAPMessage *entry, BerElement *ber,
23            BerValue *attr, BerVarray *vals )
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DESCRIPTION

26       The ldap_first_attribute(), ldap_next_attribute()  and  ldap_get_attri‐
27       bute_ber()  routines are used to step through the attributes in an LDAP
28       entry.   ldap_first_attribute()  takes  an   entry   as   returned   by
29       ldap_first_entry(3)  or  ldap_next_entry(3)  and  returns  a pointer to
30       character string containing the first attribute description in the  en‐
31       try.   ldap_next_attribute()  returns the next attribute description in
32       the entry.
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34       It also returns, in berptr, a pointer to a BerElement it has  allocated
35       to  keep  track of its current position.  This pointer should be passed
36       to subsequent calls to ldap_next_attribute() and is used to effectively
37       step  through the entry's attributes.  The caller is solely responsible
38       for freeing the BerElement pointed to by berptr when it  is  no  longer
39       needed  by  calling  ber_free(3).  When calling ber_free(3) in this in‐
40       stance, be sure the second argument is 0.
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42       The attribute names returned are suitable for inclusion in  a  call  to
43       ldap_get_values(3) to retrieve the attribute's values.
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45       The ldap_get_attribute_ber() routine allows one to iterate over all at‐
46       tributes in-place, without allocating memory to hold text for  the  at‐
47       tribute  name  or  its values, if requested. The use case is similar to
48       ldap_next_attribute() except that the attribute name is  returned  into
49       attr and, if vals is non-NULL, the list of values is stored there. Both
50       point into the LDAP message and remain valid only while  the  entry  is
51       valid.  The caller is still responsible for freeing vals with ldap_mem‐
52       free(3), if used.
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ERRORS

55       If an error occurs, NULL is returned and the ld_errno field in  the  ld
56       parameter  is  set  to indicate the error.  See ldap_error(3) for a de‐
57       scription of possible error codes.
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NOTES

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

69       OpenLDAP  Software  is developed and maintained by The OpenLDAP Project
70       <http://www.openldap.org/>.  OpenLDAP Software is derived from the Uni‐
71       versity of Michigan LDAP 3.3 Release.
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75OpenLDAP 2.6.6                    2023/07/31           LDAP_FIRST_ATTRIBUTE(3)