Change the properties of the open file fid. The following values may be passed as request:
F_DUPFD
- Return a duplicate file descriptor.
F_GETFD
- Return the file descriptor flags for fid.
F_SETFD
- Set the file descriptor flags for fid.
F_GETFL
- Return the file status flags for fid. The following codes may be returned (some of the flags may be undefined on some systems).
O_RDONLY
- Open for reading only.
O_WRONLY
- Open for writing only.
O_RDWR
- Open for reading and writing.
O_APPEND
- Append on each write.
O_CREAT
- Create the file if it does not exist.
O_NONBLOCK
- Nonblocking mode.
O_SYNC
- Wait for writes to complete.
O_ASYNC
- Asynchronous I/O.
F_SETFL
- Set the file status flags for fid to the value specified by arg. The only flags that can be changed are
O_APPEND
andO_NONBLOCK
.If successful, err is 0 and msg is an empty string. Otherwise, err is nonzero and msg contains a system-dependent error message.