#include "btree.h"
int btseln(BTA* btact, char* key, char* data, int dsize, int* rsize);
The btseln function locates and returns
the next key and data record in the file associated with the
btact context pointer. Before using
btseln, a call to btsel or btpos must be made
to initialise the position within the B Tree. Calls to btselp may be
freely intermingled with calls to btseln.
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),
btseln returns zero.
If no next key exists, btseln will return
the error code QNOKEY.
An application program can determine the number of bytes
occupied by a data record through the btrecs function.
A non-zero return from btseln indicates
an error occurred.
