#include "btree.h"
int btsel(
BTA* btact, char* key, char* data, int dsize, int* rsize)
;
The btsel
function locates and returns
the data record of an existing key in the file associated with
the btact
context pointer. Both
key
and data
are
character pointers. The dsize
parameter must contain the maximum number of bytes to be
returned. The caller should ensure that the
data
pointer refers to an area of
memory of at least dsize
bytes. The
actual number of bytes returned is returned in
rsize
. Even if the data record
contains more than dsize
bytes, only
dsize
bytes will be returned. If the
data record is successfully retrieved (even partially),
btsel
returns zero.
An application program can determine the number of bytes
occupied by a data record through the btrecs
function.
A non-zero return from btsel
indicates an
error occurred.