gistfile1.txt

example.dot:

    graph graphname {
      a -> b -> c;
      b -> d;
    }

$ graph-easy example.dot example.txt
$ cat example.txt 
          +---+
          | a |
          +---+
            |
            |
            v
+---+     +---+
| d | <-- | b |
+---+     +---+
            |
            |
            v
          +---+
          | c |
          +---+