/// Get file handle.
pub unsafe fn getfh<P: AsRef<Path>>(path: P, fh: &mut fhandle_t) -> Result<(), Errno> {
    let path = CString::new(path.as_ref());
    let path_ptr = path.as_ptr() as usize;
    let fh_ptr = core::ptr::from_mut(fh) as usize;
    unsafe { syscall2(SYS_GETFH, path_ptr, fh_ptr).map(drop) }
}
