#include <db.h>

int
db_env_set_func_dirfree(void (*func_dirfree)(char **namesp, int cnt));  

The Berkeley DB library requires the ability to return any memory allocated as part of the routine which reads through a directory and creates a list of files that the directory contains (see db_env_set_func_dirlist).

The db_env_set_func_dirfree() function 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_dirfree() function 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_dirfree() function returns a non-zero error value on failure and 0 on success.