[asterisk-users] AEL question: testing channel variables

[Allann Jones]

http://www.voip-info.org/wiki-Asterisk+variables
http://www.voip-info.org/wiki-Asterisk+Dialplan+Globals

Beware with the variable scope, if its scope is local the values can
be lost, so declare the variable as global when its value must persist
between calls.

[globals]

   FOOBAR => NO

[some_context]

if (${FOOBAR}=YES) {
   ...
}


On Sat, Jan 10, 2009 at 2:53 PM, Philipp Kempgen
<philipp.kempgen at amooma.de> wrote:
> Klaus Darilion schrieb:
>> I use the following condition:
>>
>> if (${FOOBAR}=YES) {
>>    ...
>> }
>>
>> The problem is, that if FOOBAR is not defined at all Asterisk generates
>> a warning:
>>
>> WARNING[11982]: ast_expr2.fl:407 ast_yyerror: ast_yyerror():  syntax
>> error: syntax error, unexpected '=', expecting $end; Input:
>> =YES
>>
>>
>> Of course I could use the following code, but this bloats up the code:
>>
>>
>> if (${EXISTS(${FOOBAR})}) {
>>    if (${FOOBAR}=YES) {
>>      ...
>>    }
>> }
>>
>>
>> Is there another syntax to have nice looking code but avoid the warning?
>
> if ("${FOOBAR}"="YES") {
>   ...
> }
>
> or
>
> if (x${FOOBAR}=xYES) {
>   ...
> }
>
>
>   Philipp Kempgen
>
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-- 
_______________________________
Allann J. O. Silva

"I received the fundamentals of my education in school, but that was
not enough. My real education, the superstructure, the details, the
true architecture, I got out of the public library. For an
impoverished child whose family could not afford to buy books, the
library was the open door to wonder and achievement, and I can never
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