foam-extend4.1-coherent-io/applications/solvers/solidMechanics/elasticPlasticSolidFoam/createHistory.H

OFstream * forceFilePtr(NULL);
OFstream * stressFilePtr(NULL);
word historyPatchName(mesh.solutionDict().subDict("solidMechanics").lookup("historyPatch"));
label historyPatchID = mesh.boundaryMesh().findPatchID(historyPatchName);
if(historyPatchID == -1)
  {
    Warning << "history patch " << historyPatchName
	    << " not found. Force-displacement will not be written"
	    << endl;
  }
 else if(Pstream::master())
  {
    fileName historyDir = "history";
    mkDir(historyDir);

    {
      fileName forceFileName(historyDir/"forceDisp_"+historyPatchName+".dat");
      Info << "\nForce-displacement for patch " << historyPatchName
	   << " will be written to " << forceFileName
	   << endl;
      forceFilePtr = new OFstream(forceFileName);
      OFstream& forceDispFile = *forceFilePtr;
      forceDispFile << "#Disp(mm)\tForce(N)" << endl;
    }

    {
      fileName stressFileName(historyDir/"stressStrain_"+historyPatchName+".dat");
      Info << "\nStress(Engineering Small Stress)-strain(Engineering Small Strain) for patch "
	   << historyPatchName
	   << " will be written to " << stressFileName
	   << endl;
      stressFilePtr = new OFstream(stressFileName);
      OFstream& stressStrainFile = *stressFilePtr;
      stressStrainFile << "#Strain(-)\tStress(Pa)" << endl;
    }
  }