$ apt install graphviz
  

  
$ dnf install graphviz
  

  
$ dot -Tpng hello.dot -o hello.png
  

  
digraph G {
    A -> B
    B -> C
}
  

  
graph G {
    A -- B
    B -- C
}
  

  
digraph G {
    subgraph cluster_0 {
        style=filled;
        color=lightgrey;
        label = "cluster 1";
        
        a0 -> a1 -> a2 -> a3;
        
    }

    subgraph cluster_1 {
        label = "cluster 2";
        
        b0 -> b1 -> b2 -> b3;
    }

    a1 -> b3;
    b2 -> a3;
    a3 -> a0;

}