db_env_set_func_read

#include <db.h> int db_env_set_func_read(ssize_t (*func_read)(int fd, void *buf, size_t nbytes)); Description Replace Berkeley DB calls to the IEEE/ANSI Std 1003.1 (POSIX) read function with func_read, which must conform to the standard interface. The db_env_set_func_read interface affects the entire application, not a single database or database environment. Although the db_env_set_func_read 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_read function returns a non-zero error value on failure and 0 on success. Errors The db_env_set_func_read function may fail and return a non-zero error for the following conditions: EINVAL An invalid flag value or parameter was specified. The db_env_set_func_read function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions. If a catastrophic error has occurred, the db_env_set_func_read function may fail and return DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way. See Also db_env_set_func_close, db_env_set_func_dirfree, db_env_set_func_dirlist, db_env_set_func_exists, db_env_set_func_free, db_env_set_func_fsync, db_env_set_func_ioinfo, db_env_set_func_malloc, db_env_set_func_map, db_env_set_func_open, db_env_set_func_read, db_env_set_func_realloc, db_env_set_func_seek, db_env_set_func_sleep, db_env_set_func_unlink, db_env_set_func_unmap, db_env_set_func_write, and db_env_set_func_yield.