20.1.26 ead_get_group_first_key() (acquires the first key with group specification)
- Organization of this subsection
(1) Description
This function acquires the first key in ascending order based on its ASCII code value from among all the keys that belong to a specified group. The keys that belong to groups under the specified group's hierarchy are also subject to this acquisition processing.
(2) Format
#include <eads.h> char* ead_get_group_first_key ( const EAD_CACHE *cp, /* In */ const char *group_name, /* In */ int *error_code /* Out */ );
(3) Arguments
- cp
-
Specifies the handle (pointer) to the cache in which the key is to be acquired.
Specify the handle (pointer) obtained from ead_start_cache() when access to the cache was started.
- group_name
-
Specifies a group name.
For details about the data that can be specified, see 15.2.2(2) Data that can be specified as group names.
- error_code
-
Specifies the pointer from which to retrieve the error code.
For details about error codes, see 20.2 Error codes in the client library (C).
(4) Return value
This function returns the first key in ascending order based on its ASCII code value from among all the keys that belong to the specified group.
The function returns NULL in the following cases:
-
No keys belong to the specified group.
-
Acquisition of the key failed due to an error.
(5) Notes
If acquisition of the key is successful (the return value is not NULL), the memory area is not freed automatically. You must free it in the application program. For details, see 19.1.1(10) Freeing a memory area returned as a return value.