Function getservbyport

crates/stdlib/src/socket.rs:2693–2712

(
        port: i32,
        protocolname: OptionalArg<PyStrRef>,
        vm: &VirtualMachine,
    )

    #[pyfunction]
    fn getservbyport(
        port: i32,
        protocolname: OptionalArg<PyStrRef>,
        vm: &VirtualMachine,
    ) -> PyResult<String> {
        let port = port
            .to_u16()
            .ok_or_else(|| vm.new_overflow_error("getservbyport: port must be 0-65535."))?;
        let cstr_proto = protocolname
            .as_ref()
            .map(|s| s.to_cstring(vm))
            .transpose()?;
        let cstr_proto = cstr_opt_as_ptr(&cstr_proto);
        let serv = unsafe { c::getservbyport(port.to_be() as _, cstr_proto as _) };
        if serv.is_null() {
            return Err(vm.new_os_error("port/proto not found".to_owned()));
        }
        let s = unsafe { ffi::CStr::from_ptr((*serv).s_name as _) };
        Ok(s.to_string_lossy().into_owned())
    }

    unsafe fn slice_as_uninit<T>(v: &mut [T]) -> &mut [MaybeUninit<T>] {
        unsafe { &mut *(v as *mut [T] as *mut [MaybeUninit<T>]) }