)I"Berkeley DB: DB->fd[P

DB->fd





#include <db.h>

intDB->fd(DB *db, int *fdp);





Description



The DB->fd functionGcopies a file descriptor representative of the underlying database intoGthe memory referenced by fdp. A file descriptor referencing theisame file will be returned to all processes that call db_open withGthe same file argument. This file descriptor may be safely usedAas an argument to the fcntl(2) and flock(2) lockingIfunctions. The file descriptor is not necessarily associated with any of8the underlying files actually used by the access method.

IThe Db_fd function only supports a coarse-grained form of locking.8Applications should use the lock manager where possible.

The DB->fdHfunction returns the value of errno on failure, and 0 on success.



Errors

OIf a fatal error occurs in Berkeley DB, the DB->fd function may fail and returnFDB_RUNRECOVERY, at which point all subsequent database calls will alsoreturn DB_RUNRECOVERY.

The DB->fd)function may fail and return errnoKfor any of the errors specified for the following Berkeley DB and C library functions:DBmemp->pgin(3),DBmemp->pgout(3), abort(3), close(3),dbenv->db_paniccall(3), fcntl(3), fflush(3), fprintf(3),free(3), fsync(3), getenv(3), getpid(3), getuid(3), isdigit(3),9log_compare,5log_flush, lseek(3), malloc(3), memcpy(3), memset(3),open(3), pread(3), pwrite(3), qsort(3),read(3), realloc(3),sigfillset(3),sigprocmask(3),stat(3), strerror(3), strlen(3), unlink(3), vfprintf(3), vsnprintf(3),and write(3).



See Also

8db_appexit,8db_appinit,8db_version,2DB->close,4DB->cursor,.DB->del,DB->fd,.DB->get,0DB->join,/db_open,.DB->put,0DB->stat,0DB->sync,;DBcursor->c_close,7DBcursor->c_del,6DBcursor->c_getand7DBcursor->c_put.
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