13 pub type ssize_t = isize;  typedef
499     pub fn read(fd: c_int, ptr: *mut c_void, size: size_t) -> ssize_t;  in read()
504     pub fn write(fd: c_int, ptr: *const c_void, size: size_t) -> ssize_t;  in write()
662     ) -> ssize_t;  in readlinkat()
683     pub fn pread(fd: c_int, buf: *mut c_void, count: size_t, offset: off_t) -> ssize_t;  in pread()
684     pub fn pwrite(fd: c_int, buf: *const c_void, count: size_t, offset: off_t) -> ssize_t;  in pwrite()
704     pub fn send(socket: c_int, buf: *const c_void, len: size_t, flags: c_int) -> ssize_t;  in send()
705     pub fn recv(socket: c_int, buf: *mut c_void, len: size_t, flags: c_int) -> ssize_t;  in recv()
710     pub fn readlink(path: *const c_char, buf: *mut c_char, bufsz: size_t) -> ssize_t;  in readlink()
723     pub fn getline(lineptr: *mut *mut c_char, n: *mut size_t, stream: *mut FILE) -> ssize_t;  in getline()
726     pub fn writev(fd: c_int, iov: *const crate::iovec, iovcnt: c_int) -> ssize_t;  in writev()
727     pub fn readv(fd: c_int, iov: *const crate::iovec, iovcnt: c_int) -> ssize_t;  in readv()
728     pub fn pwritev(fd: c_int, iov: *const crate::iovec, iovcnt: c_int, offset: off_t) -> ssize_t;  in pwritev()
729     pub fn preadv(fd: c_int, iov: *const crate::iovec, iovcnt: c_int, offset: off_t) -> ssize_t;  in preadv()