Call function periodically (i.e. daily)

mcosta

You can Use QTimer with a small Interval (1 minute, 1 hour) and when it expires you can check if you need to execute the function. (you can store the last execution time)

void MyClass::slotTimerExpired()
{
    QDateTime nowUtc = QDateTime::currentDateTimeUtc();
    if (m_lastExecutionTime.secsTo(nowUtc) >= 86400) // 1day = 86400 seconds
    {
        myfunction();
        m_lastExecutionTime = nowUtc;
    }
}

McLion

Thanks.
Is the int used in QTimer 32 bit wide?
I thought it is 16 bit only. If it is 32 bit wide it would be even possible to set the timer interval to a whole day as well.

mcosta

QTimer interval in a int 32bit but is in msec; so you cannot use a day interval.

McLion

... of course not ... that was some "miscalculation in my head" ... sorry

.. on second thought ... works perfectly for a whole day

SGaist

Hi,

Since you're running Linux, why not setup a cron job for that ?

mcosta

To use cron he should provide an external interface (executable to be run)

McLion

Correct.
I just need to execute a single function in my Code periodically.
btw: works perfect with the timer with an interval of a day

SGaist

@mcosta I agree, but depending on what that function should do, having a little helper program that can run without the need of the complete application might also be interesting. A cron job doesn't need to be built program, it can be written in e.g. python

mcosta

@SGaist Agree, a cron job IMO is the best solution. I'm only answering to the original question "calling a function"

McLion

Actually, the cron job would have been perfect for most of the periodic task, yes.
The periodic task is:

Download a file (SSL CA cert-bundle) from TFTP server (perfect for cron)
Compare to current local copy (perfect for cron)
If changed, replace local copy (perfect for cron)
and then update QSsl with QSslSocket::addDefaultCaCertificates

Anyhow, I finished it in Qt and it works just perfect.
Thank you guys!

..@SGaist : Grüess is Wallis us de Zentralschwiiz

SGaist

Nice !

@McLion Schöni Platz ! :)