CommandLineProcessor/cxx_main.cpp

This is an example of how to use the Teuchos::CommandLineProcessor class.

#include "Teuchos_CommandLineProcessor.hpp"
#include "Teuchos_Version.hpp"

#ifdef HAVE_MPI
#include "mpi.h"
#endif

int main(int argc, char* argv[])
{
#ifdef HAVE_MPI
  /* initialize MPI if we are running in parallel */
  MPI_Init(&argc, &argv);
  int procRank = -1;
  MPI_Comm_rank( MPI_COMM_WORLD, &procRank );
  if ( procRank == 0 )
    cout << Teuchos::Teuchos_Version() << endl << endl;
#else
  cout << Teuchos::Teuchos_Version() << endl << endl;
#endif

  // Creating an empty command line processor looks like:
  Teuchos::CommandLineProcessor My_CLP;

  /* To set and option, it must be given a name and default value.  Additionally,
     each option can be given a help string.  Although it is not necessary, a help
     string aids a users comprehension of the acceptable command line arguments.
     Some examples of setting command line options are:
  */
  // Set an integer command line option.
  int NumIters = 1550;
  My_CLP.setOption("iterations", &NumIters, "Number of iterations");
  // Set a double-precision command line option.
  double Tolerance = 1e-10;    
  My_CLP.setOption("tolerance", &Tolerance, "Tolerance");
  // Set a string command line option.
  string Solver = "GMRES";
  My_CLP.setOption("solver", &Solver, "Linear solver");
  // Set a boolean command line option.    
  bool Precondition;
  My_CLP.setOption("precondition","no-precondition",
       &Precondition,"Preconditioning flag");

  /* There are also two methods that control the strictness of the command line processor.
     For a command line processor to be sensitive to any bad command line option that it 
     does not recognize use:
  */
  My_CLP.recogniseAllOptions(true);
  
  /* Then, if the parser finds a command line option it doesn't recognize, it will
     throw an exception.  To prevent a command line processor from throwing an exception 
     when it encounters a unrecognized option or help is printed, use:
  */
  My_CLP.throwExceptions(false);
  
  //Finally, to parse the command line, argc and argv are passed to the parse method:
  My_CLP.parse( argc, argv );

#ifdef HAVE_MPI
  /* finalize MPI if we are running in parallel */
  MPI_Finalize();
#endif

  return 0;
}

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