static char help[] = "Tests PetscOptionsGetViewer() via checking output of PetscViewerASCIIPrintf().\n\n";

#include <petscviewer.h>

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

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
  PetscCall(PetscOptionsGetViewer(PETSC_COMM_WORLD, NULL, NULL, "-myviewer", &viewer, &format, NULL));
  PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
  if (iascii) {
    PetscCall(PetscViewerPushFormat(viewer, format));
    PetscCall(PetscViewerASCIIPrintf(viewer, "Testing PetscViewerASCIIPrintf %d\n", 0));
    PetscCall(PetscViewerPopFormat(viewer));
    PetscCall(PetscOptionsRestoreViewer(&viewer));
    PetscCall(PetscOptionsGetViewer(PETSC_COMM_WORLD, NULL, NULL, "-myviewer", &viewer, &format, NULL));
    PetscCall(PetscViewerPushFormat(viewer, format));
    PetscCall(PetscViewerASCIIPrintf(viewer, "Testing PetscViewerASCIIPrintf %d\n", 1));
    PetscCall(PetscViewerPopFormat(viewer));
  }
  PetscCall(PetscOptionsRestoreViewer(&viewer));
  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:
      args: -myviewer ascii:ex4w1.tmp
      filter: cat ex4w1.tmp
      output_file: output/ex4w.out

   test:
      suffix: 2
      args: -myviewer ascii:ex4w2.tmp::
      filter: cat ex4w2.tmp
      output_file: output/ex4w.out

   test:
      suffix: 3
      args: -myviewer ascii:ex4w3.tmp::write
      filter: cat ex4w3.tmp
      output_file: output/ex4w.out

   test:
      suffix: 4
      args: -myviewer ascii:ex4a1.tmp::append
      filter: cat ex4a1.tmp
      output_file: output/ex4a.out

TEST*/