[systemd-devel] Testing if timesyncd is synced

[Mantas Mikulėnas]

On Wed, Feb 20, 2019 at 3:01 PM Aurelian Melinte <ame01 at gmx.net> wrote:

> On 20/02/2019 4:18 a.m., Mantas Mikulėnas wrote:
>
> On Wed, Feb 20, 2019 at 10:55 AM Paul D. DeRocco <pderocco at ix.netcom.com>
> wrote:
>
>> What's the simplest way to test if systemd-timesyncd is currently synced
>> to the network, from within an embedded application (running with root
>> privileges)? Is there some single dbus transaction that will give me this
>> answer?
>>
>
> Call adjtimex(2) and check whether buf.status has STA_UNSYNC (should be
> unset when clock is synchronized).
>
> The systemd-timedated helper service (org.freedesktop.timedate1) exposes
> the same flag as the org.freedesktop.timedate1.NTPSynchronized property on
> /org/freedesktop/timedate1.
>
> (That said, this deliberately won't work if you've configured timesyncd to
> use "local time" instead of UTC, as timesyncd doesn't want to activate RTC
> updates in that mode.)
>
> timesyncd itself exposes several properties including the actual received
> NTPMessage, but I'm not sure if it's as good as an explicit indication. It
> does emit update signals however.
>
> --
> Mantas Mikulėnas
>
>
> Some (old?) systems do not have adjtimex:
>
> $ adjtimex
>
> -bash: adjtimex: command not found
>
>
I wasn't talking about the command-line tool, but about the Linux kernel
syscall. <http://man7.org/linux/man-pages/man2/adjtimex.2.html>

-- 
Mantas Mikulėnas
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