[Kamailio-Users] avpops OR sqlops

[Henning Westerholt]

On Mon, December 21, 2009 9:51 pm, Alex Balashov wrote:
>> also possible is to use it: if (! $avp(s:lnp_prefix)) which is shorter
>> and don't rely on the avpops module to test for null. (In sr the
>> "defined" operator can be used for the same purpose.
>
> I thought that would evaluate the numerical expression value of the AVP,
not whether it is null?

If you use the ' ! ' operator, it will evaluate the integer expression,
which of course fail if you have a string avp content:

        $avp(s:test) = "foobar";
        if (! $avp(s:test)) {
                xlog(" ! ");
        }
        if (! defined $avp(s:test)) {
                xlog("! defined");
        }
        if (strlen($avp(s:test)) == 0) {
                xlog(" strlen ");
        }

Dec 21 23:01:45 laptop ../../ser[18709]: WARNING: <core> [rvalue.c:987]:
automatic string to int conversion for "foobar" failed
Dec 21 23:01:45 laptop ../../ser[18709]: WARNING: <core> [rvalue.c:1839]:
rval expression conversion to int failed (54,8-54,19)
Dec 21 23:01:45 laptop ../../ser[18709]: ERROR: <script>:  !

If the AVP is not defined, i get this output:

Dec 21 23:14:30 laptop ../../ser[20028]: ERROR: <script>:  !
Dec 21 23:14:30 laptop ../../ser[20028]: ERROR: <script>: ! defined
Dec 21 23:14:30 laptop ../../ser[20028]: ERROR: <script>:  strlen

If I set the AVP to the empty string, i get this output:

Dec 21 23:15:54 laptop ../../ser[20152]: ERROR: <script>:  !
Dec 21 23:15:54 laptop ../../ser[20152]: ERROR: <script>:  strlen

I did also a test on kamailio, it seems that the 'defined' operator is not
equivalent to the ' ! ' operator here, as the latter evaluate to true also
if the $avp is the empty string. If also tried with to test for a not
existing header with $hdr() on sip-router, this is equivalent to the not
defined AVP.

Regards,

Henning