static char help[] = "Demonstrates PetscOptionsGetViewer().\n\n";

#include <petscviewer.h>

int main(int argc, char **args)
{
  PetscViewer       viewer;
  PetscViewerFormat format;

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
  PetscCall(PetscOptionsGetViewer(PETSC_COMM_WORLD, NULL, NULL, "-myviewer", &viewer, &format, NULL));
  PetscCall(PetscViewerPushFormat(viewer, format));
  PetscCall(PetscViewerView(viewer, PETSC_VIEWER_STDOUT_WORLD));
  PetscCall(PetscViewerPopFormat(viewer));
  PetscCall(PetscViewerDestroy(&viewer));
  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:
      args: -myviewer ascii

   testset:
      args: -myviewer hdf5:my.hdf5:hdf5_xdmf
      requires: hdf5
      test:
        suffix: 2a
        args: -viewer_hdf5_base_dimension2 false -viewer_hdf5_sp_output true  -viewer_hdf5_collective false
      test:
        suffix: 2b
        args: -viewer_hdf5_base_dimension2 true  -viewer_hdf5_sp_output false -viewer_hdf5_collective true

TEST*/