int
db_env_set_func_exists(int (*func_exists)(const char *path, int *isdirp));
Description
The Berkeley DB library requires the ability to determine if a file exists, and
optionally, if it is a file of type directory. The func argument
must conform to the following interface:
int exists(const char *path, int *isdirp);
The path argument is the pathname of the file to be checked.
If the isdirp argument 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.
The db_env_set_func_exists interface affects the entire application, not a single
database or database environment.
While the db_env_set_func_exists interface may be used to configure Berkeley DB at any time
during the life of the application, it should normally be called before
making any calls to the db_env_create or db_create functions.
The db_env_set_func_exists interface may only be used to configure Berkeley DB before
the DBENV->open interface is called.
The db_env_set_func_exists function returns a non-zero error value on failure and 0 on success.