Exec

This sample pertains to launching an external shell script from your ns-3 program.

> > Can I run a batch file which extracts trace parameters from the main
> > trace file for plotting purposes in NS3. I.e. can i add a line under
> > the finish proc to run my trace.sh?
> > 
> > proc finish {} {
> >         global ns
> >         $ns flush-trace
> >         *bash trace.sh*
> >         exec nam out.nam &
> >         exit 0
> > }

Yes, in C++ you can do this with execl(). You can read the man page on execl but here is a brief example usage:

diff -r 5209cecd2ade samples/main-simulator.cc
--- a/samples/main-simulator.cc Thu Sep 04 13:29:13 2008 -0700
+++ b/samples/main-simulator.cc Thu Sep 04 21:17:50 2008 -0700
@@ -2,6 +2,7 @@
  #include "ns3/simulator.h"
  #include "ns3/nstime.h"
  #include <iostream>
+#include <unistd.h>

  using namespace ns3;

@@ -43,5 +44,6 @@ int main (int argc, char *argv[])

    Simulator::Run ();
+  execl("/bin/bash", "/home/user/ns-3-dev/trace.sh", "trace.sh", NULL);
    Simulator::Destroy ();
 }