/// Make a new name for a file.
///
/// # Examples
///
/// ```
/// let oldname = "/etc/passwd";
/// let newname = "/tmp/nc-symlinkat";
/// let ret = unsafe { nc::symlinkat(oldname, nc::AT_FDCWD, newname) };
/// assert!(ret.is_ok());
/// let ret = unsafe { nc::unlinkat(nc::AT_FDCWD, newname, 0) };
/// assert!(ret.is_ok());
/// ```
pub unsafe fn symlinkat<P: AsRef<Path>>(
    old_name: P,
    new_dirfd: i32,
    new_name: P,
) -> Result<(), Errno> {
    let old_name = CString::new(old_name.as_ref());
    let old_name_ptr = old_name.as_ptr() as usize;
    let new_dirfd = new_dirfd as usize;
    let new_name = CString::new(new_name.as_ref());
    let new_name_ptr = new_name.as_ptr() as usize;
    unsafe { syscall3(SYS_SYMLINKAT, old_name_ptr, new_dirfd, new_name_ptr).map(drop) }
}
