#include <db.h>

int
db_env_set_func_exists(int (*func_exists)(const char *path, int *isdirp));

The Berkeley DB library requires the ability to determine whether a file exists and whether it is a file of type directory.

The db_env_set_func_exists method configures all operations performed by a process and all of its threads of control, not operations confined to a single database environment.

Although the db_env_set_func_exists method may be called at any time during the life of the application, it should normally be called before making calls to the db_env_create or db_create methods.

The db_env_set_func_exists method returns a non-zero error value on failure and 0 on success.

• The func_exists parameter is the function which returns if a file exists and if it is a file of type directory.

  The path parameter to this function is the pathname of the file to be checked.

  If the isdirp parameter is non-NULL, it must be set to non-0 if path is a directory, and 0 if path is not a directory.

  The func_exists function must return the value of errno on failure and 0 on success.