mdlInput inp(fp);

while (inp.NumRemain() > 0) {

   mdlKey k = inp.BeginChunk();

   // Do something that depends on k
      
   inp.EndChunk();
   }

This demonstrates the use of NumRemain at the file scope to test for end of file.

Here is some partial code for reading polygon meshes:

void ReadMesh(mdlInput &inp, Mesh &mesh) {

   // We have already started a msh chunk

   mesh.name = strdup(inp.ReadString());
   ReadMaterial(inp, mesh.material);

   while (inp.NumRemain() > 0) {
      mdlKey k = inp.BeginChunk();
      if (k == mdlKey("vrtxPstn")) {
         mesh.numVertices = inp.NumRemain() / 3;
         int n = inp.ReadFloats(mesh.vp, mesh.numVertices * 3);
         assert(n == mesh.numVertices * 3);
         }
      inp.EndChunk();
      }
   }

This demonstrates using NumRemain and ReadFloats to quickly read in a large list of numbers.