[SR-Users] Evaluate Perl Return Value in Routing Logic

[Henning Westerholt]

On Tuesday 17 August 2010, Nicolas Rüger wrote:
> thanks for the help. Your idea kept me trying as the C-code shows that it
>  should return the result from the PERL subroutine as you already mentioned
>  in your answer.
> 
> Two points I want to name here:
> 
> 1)
> 
> I'm still confused that the methods in perl/perlfunc.c are called
>  "perl_exec1()" and "perl_exec2()" instead of "perl_exec" because that's
>  the one for use in kamailio.cfg.

Hey Nicolas,

this is not defined in the C, but in the module interface. Take a look to the 
perl.c:static cmd_export_t cmds[] variable.

> 2) More Important...
> 
> 
> I finally solved my issue by using a variable in kamailio.cfg:
> 
> 
> if (is_method("INVITE")) {
>         $var(a) = perl_exec("my_perl_subroutine");
>         if ($var(a) == -1){
>  	 	xlog("PERL returns -1 \n");
>  	}
> }
> 
> That works!
> 
> So is this behavior of kamailio.cfg a bug?
> It should at least be listed in the documentation cause it's really tricky.
> 
> 
> PLEASE NOTE:
> 
>  perl_exec("my_perl_subroutine") == -1    --> returns FALSE
> 
> BUT
> 
>  $var(a) = perl_exec("my_perl_subroutine");
>  $var(a) == -1                              --> returns TRUE

This is indeed strange. I'd say that evaluating the return value of a function 
is nothing that new, its has been a pretty long time there. Maybe the 
comparison went somehow mad because of some typing issue? Another idea, have 
you tried using the $rc PV, which also return the result of the last called 
function?

Regards,

Henning