suppress output

Hello,
I am using GLPK through the C API.  I am using it on the Mac, installed by MacPorts, version: GLPK Simplex Optimizer, v4.65.  I am using it to solve an integer linear programming problem.  The function I call is glp_intopt.

It works, but I cannot figure out how to suppress output from this routine.  I have tried this: 

  glp_iocp parm;
  glp_init_iocp(&parm);
...
  parm.presolve = GLP_ON;
  parm.msg_lev = GLP_MSG_OFF;
...
  glp_intopt(prob, &parm)


Setting the level to GLP_MSG_OFF helps —— it gets rid of some of the output —— but does not get rid of all the output.  For example, I still get this:

...
Long-step dual simplex will be used
Applying PROXY heuristic...
Proxy's time limit set to 10 seconds.
Proxy's relative improvement set to 1.00 %.
Searching for a feasible solution...
>>>>> first solution = 3.000000e+00;
Time used: 0.7 secs.  Memory used: 0.2 Mb
Starting proximity search...
Bound exceeded = -6.000000. Proxy heuristic terminated.
Time used: 0.7.  Memory used: 0.2 Mb
Objective value: 3.000000
...

Any idea how to suppress this, or at least direct it to a file, using the API?

Thanks,
Steve