#include <db.h>

int
DB_ENV->remove(DB_ENV *dbenv, char *db_home, u_int32_t flags);  

The DB_ENV->remove() method destroys a Berkeley DB environment if it is not currently in use. The environment regions, including any backing files, are removed. Any log or database files and the environment directory are not removed.

If there are processes that have called DB_ENV->open() without calling DB_ENV->close() (that is, there are processes currently using the environment), DB_ENV->remove() will fail without further action unless the DB_FORCE flag is set, in which case DB_ENV->remove() will attempt to remove the environment, regardless of any processes still using it.

The result of attempting to forcibly destroy the environment when it is in use is unspecified. Processes using an environment often maintain open file descriptors for shared regions within it. On UNIX systems, the environment removal will usually succeed, and processes that have already joined the region will continue to run in that region without change. However, processes attempting to join the environment will either fail or create new regions. On other systems in which the unlink(2) system call will fail if any process has an open file descriptor for the file (for example Windows/NT), the region removal will fail.

Calling DB_ENV->remove() should not be necessary for most applications because the Berkeley DB environment is cleaned up as part of normal database recovery procedures. However, applications may want to call DB_ENV->remove() as part of application shut down to free up system resources. For example, if the DB_SYSTEM_MEM flag was specified to DB_ENV->open(), it may be useful to call DB_ENV->remove() in order to release system shared memory segments that have been allocated. Or, on architectures in which mutexes require allocation of underlying system resources, it may be useful to call DB_ENV->remove() in order to release those resources. Alternatively, if recovery is not required because no database state is maintained across failures, and no system resources need to be released, it is possible to clean up an environment by simply removing all the Berkeley DB files in the database environment's directories.

In multithreaded applications, only a single thread may call the DB_ENV->remove() method.

A DB_ENV handle that has already been used to open an environment should not be used to call the DB_ENV->remove() method; a new DB_ENV handle should be created for that purpose.

After DB_ENV->remove() has been called, regardless of its return, the Berkeley DB environment handle may not be accessed again.

The DB_ENV->remove() method returns a non-zero error value on failure and 0 on success.