LDAP_SORT(3)						     Library Functions Manual						      LDAP_SORT(3)

NAME

       ldap_sort_entries, ldap_sort_values, ldap_sort_strcasecmp - LDAP sorting routines

LIBRARY

       OpenLDAP LDAP (libldap, -lldap)

SYNOPSIS

       #include <ldap.h>

       ldap_sort_entries(ld, chain, attr, cmp)
       LDAP *ld;
       LDAPMessage **chain;
       char *attr;
       int (*cmp)();

       ldap_sort_values(ld, vals, cmp)
       LDAP *ld;
       char **vals;
       int (*cmp)();

       ldap_sort_strcasecmp(a, b)
       char *a;
       char *b;

DESCRIPTION

       These  routines are used to sort lists of entries and values retrieved from an LDAP server.  ldap_sort_entries() is used to sort a chain of
       entries retrieved from an LDAP search call either by DN or by some arbitrary attribute in the entries.  It takes ld,  the  LDAP	structure,
       which  is  only	used  for  error  reporting,  chain,  the  list of entries as returned by ldap_search_s(3) or ldap_result(3).  attr is the
       attribute to use as a key in the sort or NULL to sort by DN, and cmp is the comparison function to use when comparing values (or individual
       DN  components  if sorting by DN).  In this case, cmp should be a function taking two single values of the attr to sort by, and returning a
       value less than zero, equal to zero, or greater than zero, depending on whether the first argument is less than, equal to, or greater  than
       the second argument.  The convention is the same as used by qsort(3), which is called to do the actual sorting.

       ldap_sort_values()  is  used  to  sort  an  array of values from an entry, as returned by ldap_get_values(3).  It takes the LDAP connection
       structure ld, the array of values to sort vals, and cmp, the comparison function to use during the sort.  Note that cmp will  be  passed  a
       pointer to each element in the vals array, so if you pass the normal char ** for this parameter, cmp should take two char **'s as arguments
       (i.e., you cannot pass strcasecmp or its friends for cmp).  You can, however, pass the function ldap_sort_strcasecmp() for this purpose.

       For example:

	    LDAP *ld;
	    LDAPMessage *res;

	    /* ... call to ldap_search_s(), fill in res, retrieve sn attr ... */

	    /* now sort the entries on surname attribute */
	    if ( ldap_sort_entries( ld, &res, "sn", ldap_sort_strcasecmp ) != 0 )
		 ldap_perror( ld, "ldap_sort_entries" );

NOTES

       The ldap_sort_entries() routine applies the comparison function to each value of the attribute in the  array  as  returned  by  a  call	to
       ldap_get_values(3), until a mismatch is found.  This works fine for single-valued attributes, but may produce unexpected results for multi-
       valued attributes.  When sorting by DN, the comparison function is applied to an exploded version of the DN,  without  types.   The  return
       values  for  all  of these functions are declared in the <ldap.h> header file.  Some routines may dynamically allocate memory.  Callers are
       responsible for freeing such memory using the supplied deallocation routines.

SEE ALSO

       ldap(3), ldap_search(3), ldap_result(3), qsort(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 2.1.X							    RELEASEDATE 						      LDAP_SORT(3)