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

#include <petscsys.h>
int main(int argc, char **argv)
{
  PetscBool  found;
  char       localname[PETSC_MAX_PATH_LEN];
  const char url[] = "https://web.cels.anl.gov/projects/petsc/download/datafiles/matrices/tiny";

  /*
    Every PETSc routine should begin with the PetscInitialize() routine.
    argc, argv - These command line arguments are taken to extract the options
                 supplied to PETSc and options supplied to MPI.
    help       - When PETSc executable is invoked with the option -help,
                 it prints the various options that can be applied at
                 runtime.  The user can use the "help" variable place
                 additional help messages in this printout.
  */
  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &argv, NULL, help));
  PetscCall(PetscFileRetrieve(PETSC_COMM_WORLD, url, localname, PETSC_MAX_PATH_LEN, &found));
  if (found) {
    PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Successfully download file %s\n", localname));
  } else SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "Unable to download url %s", url);

  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:
     requires: defined(PETSC_HAVE_POPEN)

TEST*/