asterisk users - Nov 2015 - How to encode plus sign in REGEX function in dialplan?

Dear all,

I have made a fairly complex dialplan where I am using the REGEX function in
many places. This works so far, but I wasn't able to solve the following
problem. What I would like to do is the following (please note that this is
normal regex syntax and obviously not what the REGEX function expects, but I
hope it shows the idea):

  same => n(A1), GotoIf($[${REGEX("^\+49.*" ${EXTEN})}]?:A2)

This line should make Asterisk jump to label A2 if the extension begins with
+49. Since the plus sign is a special char in regexes, I have escaped it with \
as usual. But that does not work; the pattern is not matched and the goto is not
executed when the extension begins with +49.

What I already have tried:

1) same => n(A1), GotoIf($[${REGEX("^\\+49.*" ${EXTEN})}]?:A2)

2) same => n(A1), GotoIf($[${REGEX("^\\\+49.*" ${EXTEN})}]?:A2)

3) same => n(A1), GotoIf($[${REGEX("^\\\\+49.*" ${EXTEN})}]?:A2)

4) same => n,     Set(REPAT=^+49.*) 
   same => n(A1), GotoIf($[${REGEX(${REPAT} ${EXTEN})}]?:A2)

5) same => n, Set(REPAT="^+49.*")
   same => n(A1), GotoIf($[${REGEX(${REPAT} ${EXTEN})}]?:A2)

6) same => n, Set(REPAT=^+49.*)
   same => n(A1), GotoIf($[${REGEX("${REPAT}" ${EXTEN})}]?:A2)

7) same => n, Set(REPAT="^+49.*")
   same => n(A1), GotoIf($[${REGEX("${REPAT}" ${EXTEN})}]?:A2)

Neither of these worked.

Actually, the REGEX function is not able to handle normal regular expressions.
To make things worse, there doesn't seem to be any documentation. Could
anybody please point me to documentation or tell me how write that very simple
pattern?

Thank you very much,

Recursive

P.S. This happens in Asterisk 13.6.0 - I haven't tested with other versions.

On Thu, Nov 5, 2015 at 12:49 AM, Recursive <lists at binarus.de>
wrote:
> Dear all,
>
> I have made a fairly complex dialplan where I am using the REGEX function
in many places. This works so far, but I wasn't able to solve the following
problem. What I would like to do is the following (please note that this is
normal regex syntax and obviously not what the REGEX function expects, but I
hope it shows the idea):
>
>   same => n(A1), GotoIf($[${REGEX("^\+49.*" ${EXTEN})}]?:A2)
>
> This line should make Asterisk jump to label A2 if the extension begins
with +49. Since the plus sign is a special char in regexes, I have escaped it
with \ as usual. But that does not work; the pattern is not matched and the goto
is not executed when the extension begins with +49.
>
> What I already have tried:
>
> 1) same => n(A1), GotoIf($[${REGEX("^\\+49.*" ${EXTEN})}]?:A2)
>
> 2) same => n(A1), GotoIf($[${REGEX("^\\\+49.*"
${EXTEN})}]?:A2)
>
> 3) same => n(A1), GotoIf($[${REGEX("^\\\\+49.*"
${EXTEN})}]?:A2)
>
> 4) same => n,     Set(REPAT=^+49.*)
>    same => n(A1), GotoIf($[${REGEX(${REPAT} ${EXTEN})}]?:A2)
>
> 5) same => n, Set(REPAT="^+49.*")
>    same => n(A1), GotoIf($[${REGEX(${REPAT} ${EXTEN})}]?:A2)
>
> 6) same => n, Set(REPAT=^+49.*)
>    same => n(A1), GotoIf($[${REGEX("${REPAT}" ${EXTEN})}]?:A2)
>
> 7) same => n, Set(REPAT="^+49.*")
>    same => n(A1), GotoIf($[${REGEX("${REPAT}" ${EXTEN})}]?:A2)
>
> Neither of these worked.
>
> Actually, the REGEX function is not able to handle normal regular
expressions. To make things worse, there doesn't seem to be any
documentation. Could anybody please point me to documentation or tell me how
write that very simple pattern?
>
> Thank you very much,
>
> Recursive
>
> P.S. This happens in Asterisk 13.6.0 - I haven't tested with other
versions.
The documentation for that function is available at the CLI "core show
function REGEX" and is available on the wiki at
https://wiki.asterisk.org/wiki/display/AST/Asterisk+13+Function_REGEX

It should be able to handle typical regular expression. I don't see
anything wrong with what you are doing. Please file a bug at
issues.asterisk.org/jira.  Do include a debug log on the issue
captured when Asterisk attempts to execute these extensions.

https://wiki.asterisk.org/wiki/display/AST/Collecting+Debug+Information

Thanks,

-- 
Rusty Newton
Digium, Inc. | Community Support Manager
445 Jan Davis Drive NW - Huntsville, AL 35806 - US
direct: +1 256 428 6200

Check us out at: http://digium.com & http://asterisk.org

On 06.11.2015 14:06, Rusty Newton wrote:
> On Thu, Nov 5, 2015 at 12:49 AM, Recursive <lists at binarus.de>
wrote:
>>
>>   same => n(A1), GotoIf($[${REGEX("^\+49.*"
${EXTEN})}]?:A2)
>> [..]
>> Actually, the REGEX function is not able to handle normal regular
expressions. To make things worse, there doesn't seem to be any
documentation. Could anybody please point me to documentation or tell me how
write that very simple pattern?
>>
> 
> The documentation for that function is available at the CLI "core show
> function REGEX" and is available on the wiki at
> https://wiki.asterisk.org/wiki/display/AST/Asterisk+13+Function_REGEX
At first, thank you very much for your reply.

Of course, I had found and read that part of the documentation before posting
here. But in this documentation (and any other I came across), I couldn't
find any hint about if and how to encode special characters, about what sort of
regular expressions are allowed (Perl, extended, Sed etc.), or about what RE
engine is used internally. This is what I meant by claiming "no
documentation".
> It should be able to handle typical regular expression. I don't see
> anything wrong with what you are doing. Please file a bug at
> issues.asterisk.org/jira.  Do include a debug log on the issue
> captured when Asterisk attempts to execute these extensions.
> 
> https://wiki.asterisk.org/wiki/display/AST/Collecting+Debug+Information
 
I really was hoping to do something wrong. I'll try to file a bug and enable
others to reproduce by giving a simple example with standard configuration so
that I don't need to upload mine.

Regards,

Recursive

On 06.11.2015 14:06, Rusty Newton wrote:
> 
> It should be able to handle typical regular expression. I don't see
> anything wrong with what you are doing. Please file a bug at
> issues.asterisk.org/jira.  Do include a debug log on the issue
> captured when Asterisk attempts to execute these extensions.
> 
> https://wiki.asterisk.org/wiki/display/AST/Collecting+Debug+Information
> 
Thanks to your above hint, I have reviewed my dialplan again and have found a
bug in it. After correcting my dialplan, it turned out that you are right (of
course): REGEX now behaves like expected.

The reason why I even have thought of REGEX not behaving like expected: The
other day I have read some tutorials / articles about variables and strings in
Asterisk dialplans. One of them (I really can't remember which one) claimed
that there were problems with special characters in strings, for example with
the dollar character ($). They recommended to do something like the following
*if* such problems would show:

Set(DOLLAR=$)
... head_of_string${DOLLAR}tail_of_string

They also claimed that there were other problematic characters which could be
handled the same way. That seemed logic to me and lead me into thinking that the
pattern string in the REGEX call could be affected by this; hence my initial
post.

I am apologizing that I haven't found the bug in my dialplan at an earlier
time.

Best regards,

Recursive