ntpdate-like functionality in ntpd

[Denys Vlasenko]

On Tue, Jan 27, 2015 at 11:01 PM, Guillermo Rodriguez Garcia
<guille.rodriguez at gmail.com> wrote:
> Hello Denys,
>
> El martes, 27 de enero de 2015, Denys Vlasenko <vda.linux at googlemail.com>
> escribió:
>
>> On Tue, Jan 27, 2015 at 7:27 PM, Guillermo Rodriguez Garcia
>> <guille.rodriguez at gmail.com> wrote:
>> > Hello all,
>> >
>> > Is there a way to make ntpd work just like ntpdate (just use the first
>> > response received to set the time)? This is to set the approximate
>> > time at boot as quickly as possible before starting other time sensitive
>> > services.
>> >
>> > The closest I can get is ntpd -nqp <server> but this seems to need
>> > 5 valid samples in order to set the time.
>>
>> Would it work for you if you simply background it
>> and let it do its work in parallel with the rest of the boot?
>
>
> Not in this particular case; I don't need time to be extremely accurate but
> I need "approximate" time to be set as quickly as possible before starting
> other services. That is (was) the typical use case of ntpdate: set the time
> quickly to an approximate value, then let ntpd do it's job.

I think the best way to achieve this is to implement a sntp applet

http://linux.die.net/man/8/sntp

It can reuse ntpd's code.

-- 
vda