Function if_indextoname 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn if_indextoname(
    idx: c_uint,
    buf: *mut c_char,
) -> *const c_char

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/if_indextoname.html.

Safety

Returns only static lifetime references to const names, does not reuse the buf pointer. Returns NULL in case of not found + ERRNO being set to ENXIO. Currently only checks against inteface index 1.