Have you tried with kamctl, which uses jsonrpc and theoretically you can pass empty values for parameters?

The binrpc was designed by SER devs during 2005-2008, not sure if there is any specs for the packet format and whether empty values are supported or not.

Cheers,
Daniel

Then I don’t think it is possible as kamcmd uses kamailio binrpc protocol which in turn accepts string or int as an arguments and string should be 0 terminated.

I’ve tried to reproduce your use case and execute  kamcmd “cfg.reset group” - it should set the value to the default..  but it crushes my 5.5.0 

On Fri, 11 Jun 2021 at 8:53 PM, Sergey Safarov <s.safarov@gmail.com> wrote:

yes, Arsen, you are correct.

On Fri, Jun 11, 2021 at 5:20 PM Arsen Semenov <arsperger@gmail.com> wrote:

Hello Sergey,

Am I understanding you right, that you've defined a custom global variable with an empty value in the kamailio.cfg
and then want to set a string value to it and then by executing cfg.sets global var_name "" want to clear that value to be blank again? 

On Fri, Jun 11, 2021 at 4:31 PM Sergey Safarov <s.safarov@gmail.com> wrote:

In Kamailio config I use empty global string variable

local.trace_troubleshooting_net = "" descr "trace all SIP messages from given network"

When I check variable value I get blank string

kamcmd cfg.get local trace_troubleshooting_net

I can set new value

[root@host]# kamcmd cfg.sets local trace_troubleshooting_net "2600::/48"
[root@host]# kamcmd cfg.get local trace_troubleshooting_net

2600::/48

Now I want to set the empty custom  global variable using a command

kamcmd cfg.sets group trace_troubleshooting_net ""

But get error

error: 400 - error at parameter 2: expected string type but record doesn't match type

How to properly set empty values?

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