129     pub fn open(path: &str, mode: FileMode) -> Result<usize, SystemError> {  in open()
194     pub fn close(fd: usize) -> Result<usize, SystemError> {  in close()
206     pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> {  in read()
224     pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> {  in write()
242     pub fn lseek(fd: i32, seek: SeekFrom) -> Result<usize, SystemError> {  in lseek()
274     pub fn chdir(dest_path: &str) -> Result<usize, SystemError> {  in chdir()
308     pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> {  in getdents()
333     pub fn mkdir(path: &str, mode: usize) -> Result<usize, SystemError> {  in mkdir()
346     pub fn unlinkat(_dirfd: i32, pathname: &str, flags: u32) -> Result<usize, SystemError> {  in unlinkat()
377     pub fn dup(oldfd: i32) -> Result<usize, SystemError> {  in dup()
412     pub fn dup2(oldfd: i32, newfd: i32) -> Result<usize, SystemError> {  in dup2()
459     pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> {  in fcntl()
562     pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> {  in ftruncate()
620     pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> {  in fstat()
662         iovcnt: usize,  in from_user()