Re: [ns] On-the-fly ns2 interpreter

Hi all,

I fixed this problem by creating a shared library of ns (similar to the
cygwin approach), i.e. libns.so, and linking it to my code.

Upon closer inspection, ~ns/lib/ns-lib.tcl:128 has "class Simulator"
commented. It is instead provided by an OTcl class in
~ns/common/simulator.[h/cc]. Dynamically linking libns.so provided the
missing class definition and solved the error that I reported earlier.

I guess this falls under the "grey area" mentioned in the documentation:
http://isi.edu/nsnam/ns/doc/node6.html

On to greener pastures.

Best,
Nikhil

On Tue, Dec 13, 2011 at 3:30 PM, Nikhil Karnad <nikhil.karnad@gmail.com>wrote:

> Hi everyone,
>
> Firstly, great job to the team on the wiki, forums, and mailing lists. It
> really helped me to get to speed with ns2.
>
> I'd like to use ns2 along with external packet data sources in real-time,
> e.g. a message received on a socket on my linux PC should be sent over the
> network currently being simulated in ns2. My current understanding is that
> the events have to be specified in a Tcl script before the simulation is
> run (via the Simulator class/command). Once the simulation is running, and
> a packet arrives on my socket, I would like to "inject" an event into the
> simulator.
>
> The rest of my code is in C++. My approach: I extracted some of the code
> from the ns source (~ns/common/tclAppInit.cc) and tried to create an
> instance of the interpreter myself, and then plan to use Tcl::eval() and
> its variants to interface with the simulator in real-time...similar to what
> ns does on an input script file. I'm having trouble with the EmbeddedTcl
> codes from "~ns/gen/ns_tcl.cc" and "~ns/gen/ptypes.cc". After calling
> et_ns_ptypes.load() and et_ns_lib.load(), I was assuming that the ns2 OTcl
> classes would be available, but when I run 'tcl.evalc("set ns [new
> Simulator]");', I get the following run-time error:
>
> mytest:
>> [code omitted because of length]
>> : invalid command name "Simulator"
>> while executing
>> "Simulator proc address-format {} {
>> return [Simulator set AddressFormat_]
>> }"
>>
>
> What am I missing from the ns2 source that imported the class definitions
> into the Tcl interpreter? Is there a scoping difference between
> Tcl::evalc() and Tcl_Eval()?
>
> Any help is greatly appreciated. For those interested, the simple code I
> have is available here:
> http://pastebin.com/LXmsgiya
>
> Thanks,
> Nikhil