introduction_ex1.C File Reference

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Functions
int	main (int argc, char **argv)

Function Documentation

main()

int main	(	int	argc,
		char **	argv
	)

Definition at line 39 of file introduction_ex1.C.

{
  // Initialize the library.  This is necessary because the library
  // may depend on a number of other libraries (i.e. MPI and PETSc)
  // that require initialization before use.  When the LibMeshInit
  // object goes out of scope, other libraries and resources are
  // finalized.
  LibMeshInit init (argc, argv);
 
  // Check for proper usage. The program is designed to be run
  // as follows:
  // ./ex1 -d DIM input_mesh_name [-o output_mesh_name]
  // where [output_mesh_name] is an optional parameter giving
  // a filename to write the mesh into.
  if (argc < 4)
    {
      // This handy function will print the file name, line number,
      // specified message, and then throw an exception.
      libmesh_error_msg("Usage: " << argv[0] << " -d 2 in.mesh [-o out.mesh]");
    }
 
  // Get the dimensionality of the mesh from argv[2]
  const unsigned int dim = std::atoi(argv[2]);
 
  // Skip higher-dimensional examples on a lower-dimensional libMesh build
  libmesh_example_requires(dim <= LIBMESH_DIM, "2D/3D support");
 
  // Create a mesh, with dimension to be overridden later, on the
  // default MPI communicator.
  Mesh mesh(init.comm());
 
  // We may need XDR support compiled in to read binary .xdr files
  std::string input_filename = argv[3];
#ifndef LIBMESH_HAVE_XDR
  libmesh_example_requires(input_filename.rfind(".xdr") >=
                           input_filename.size(), "XDR support");
#endif
 
  // Read the input mesh.
  mesh.read (argv[3]);
 
  // Print information about the mesh to the screen.
  mesh.print_info();
 
  // Write the output mesh if the user specified an
  // output file name.
  if (argc >= 6 && std::string("-o") == argv[4])
    {
      // We may need XDR support compiled in to read binary .xdr files
      std::string output_filename = argv[5];
#ifndef LIBMESH_HAVE_XDR
      libmesh_example_requires(output_filename.rfind(".xdr") >=
                               output_filename.size(), "XDR support");
#endif
 
      mesh.write (argv[5]);
    }
 
  // All done.  libMesh objects are destroyed here.  Because the
  // LibMeshInit object was created first, its destruction occurs
  // last, and it's destructor finalizes any external libraries and
  // checks for leaked memory.
  return 0;
}

References dim, libMesh::TriangleWrapper::init(), mesh, libMesh::MeshBase::print_info(), libMesh::MeshBase::read(), and libMesh::MeshBase::write().