#include "btree.h"
BTA* btopn(char* fid, int mode, int shared);
The btopn function will open an existing
B Tree file. The parameter fid must be
set to the name of the file to open. The
mode parameter determines if the B Tree
file can be updated. A value of zero indicates that updates
are allowed, a non-zero value will prohibit updates. The
parameter shared should be set to zero
to disallow shared access to the B Tree file, or non-zero to
allow shared access.
btopn will return a pointer to the BT
activation context for the newly opened file (BTA*), or NULL
in the case of an error. To determine the cause of an error,
invoke the btcerr
function.
If the B Tree index file has been successfully opened, the default root is selected, and the file is ready for further operations.