1  char a[] = "12345";
       2  char b[] = "12345";
       3  
       4  void loop (char * pz, char * pzDta)
       5  {
       6      for (;;) {
       7          switch (*(pz++) = *(pzDta++)) {
       8          case 0:
       9    	    goto loopDone2;
      10  
      11  	case '"':
      12  	case '\\':
      13  	    pz[-1]  = '\\';
      14              *(pz++) = pzDta[-1];
      15  	}
      16      } loopDone2:;
      17  
      18    if (a - pz != b - pzDta)
      19      abort ();
      20  }
      21  
      22  main()
      23  {
      24    loop (a, b);
      25    exit (0);
      26  }