dot命令生成流程图

    dot命令是graphviz的一部分，通过编写一些类似脚本的语言，可以容易地生成流程图。下面在新建一个文件tmp.dot，内容如下：

digraph G {
# 定义全局属性
    fontname = "Courier New"
    fontsize = 8
    # 从下往上
    rankdir = BT
# 定义节点属性
    node [
            shape = "record" # 矩形，默认是椭圆
            color = "blue" # 边框蓝色
    ]

# 定义边的属性
    edge [
            fontsize = 9
    ]
# 换行符是\l，而要新建一个新的单元格，则需要是用|。{}里面的是内容
    Reportable [
	    label = "{Reportable | + getSummary() : Map\<String, Integer\> | + getDetail() : Map\<String, Integer\> | + isDetailVisible() : boolean}"
    ]
# 特殊字符要转义
    LineCounter [
	    label = "{LineCounter | + count(String line) : boolean | + getType() : String}"
    ]

    CharCounter [
	    label = "{CharCounter | + count(Character c) : boolean | + getType() : String}"
    ]

   AbstractCharCounter [
	    label = "{AbstractCharCounter | characterMap : Map\<Character, Integer\> | + count(Character c) : boolean | + getSummary() : Map\<String, Integer\> | +getDetail() : Map\<String, Integer\> }"
    ]
   
   AbstractLineCounter [
	    label = "{AbstractLineCounter |  + count(String line) : boolean | + getSummary() : Map\<String, Integer\> | +getDetail() : Map\<String, Integer\> }"
    ]

   PredicateCharacter[label = "{Predicate\<Character\> | + apply(Character c) : boolean}"]
   PredicateString[label = "{Predicate\<String\> | + apply(String line) : boolean}"]

   BlankCharCounter[label = "{BlankCharCounter | + apply(Character c) : boolean | + getType() : String | + isDetailVisible() : boolean }"]
   ChineseCharCounter[label = "{ChineseCharCounter | - chinesePattern : Pattern | + apply(Character c) : boolean | + getType() : String | + isDetailVisible() : boolean }"]
   LetterCharCounter[label = "{LetterCharCounter | - chinesePattern : Pattern | + apply(Character c) : boolean | + getType() : String | + isDetailVisible() : boolean }"]
    NumberCharCounter[label = "{NumberCharCounter | + apply(Character c) : boolean | + getType() : String | + isDetailVisible() : boolean }"]
    LineNumberCounter[label = "{LineNumberCounter | + apply(Character c) : boolean | + getType() : String | + isDetailVisible() : boolean }"]
   

    parentInterface [label = "parent interface" color = "green" style=filled]
    childInterface [label = "child interface" color = "green" style=filled]
    abstractClass [ label = "abstract class : implement some methods using the abstract methods" color = "green" style=filled]
    specificClass [ label = "specific class : implement all unimplemented methods" color = "green" style=filled]

    LineProcessor [label = "{LineProcessor\<List\<Reportable\>\>}" ]
    ReportableLineProcessor [ label = "{ReportableLineProcessor | + ReportableLineProcessor() | + processsLine(String line) : boolean | + getResult() : List\<Reportable\>}"]

    # 定义在同一层
    {rank = same; parentInterface; Reportable; LineProcessor}
    {rank = same; childInterface; LineCounter; CharCounter; PredicateCharacter; PredicateString}
    {rank = same; abstractClass; AbstractLineCounter; AbstractCharCounter;}
    {rank = same; specificClass; LineNumberCounter; BlankCharCounter; ChineseCharCounter; LetterCharCounter; NumberCharCounter; ReportableLineProcessor}
    
   # 箭头为空心，接口之间的继承
   LineCounter -> Reportable[arrowhead="empty"]
   CharCounter -> Reportable[arrowhead="empty"]
   AbstractCharCounter -> CharCounter[arrowhead="empty"]
   AbstractLineCounter -> LineCounter[arrowhead="empty"]

   AbstractCharCounter -> PredicateCharacter[arrowhead="empty"]
   AbstractLineCounter -> PredicateString[arrowhead="empty"]

   # 实现类的UML
   BlankCharCounter -> AbstractCharCounter[arrowhead="empty", style="dashed"]
   ChineseCharCounter -> AbstractCharCounter[arrowhead="empty", style="dashed"]
   LetterCharCounter -> AbstractCharCounter[arrowhead="empty", style="dashed"]
   NumberCharCounter -> AbstractCharCounter[arrowhead="empty", style="dashed"]
   LineNumberCounter -> AbstractLineCounter[arrowhead="empty", style="dashed"]

   ReportableLineProcessor -> LineProcessor[arrowhead="empty", style="dashed"]
  
}

    首先安装graphviz

sudo apt-get install graphviz

    然后生成运行如下命令，生成流程图：

dot -Tpng -o hello.png tmp.dot

    打开图片：

xdg-open hello.png

    结果如下：

实例2:

digraph otherOp{
        node [
            shape = "record"
            color = "blue"
    	]
	edge[
	    arrowhead = "empty"
	]
	
	// 子图，必须以cluster开头
	subgraph cluster0{
		// 子图用浅灰色填充
		style = filled
		color = lightgray
		// 子图名字
		label = "web server"
		// 制定整个client_socket填充，且填充的颜色为red，这时边缘是蓝色。不指定颜色，则会用上面的边缘颜色blue填充，导致无法看到边缘。
        	// 这里使用s0,s1...占位符号
		client_socket [label = "{<s0>|<s1>head|<s2>|<s3>...|<s4>|<s5>tail|<s6>}" style = "filled" fillcolor = "red"]

       		// 指定边上的文字
		master_thread -> client_socket : s1[label = "produce socket"]

		worker_thread [label = "{<w0> worker_thread 1| <w1> worker_thread 2 | <w2>worker_thread 3}"]
		client_socket : s5 -> worker_thread : w0
        	client_socket : s4 -> worker_thread : w1 [ label = "consume socket"]
        	client_socket : s3 -> worker_thread : w2
  	
		producer[ label = "producer" style = filled fillcolor = "green"]
		consumer[ label = "comsumer" style = filled fillcolor = "green"]
		Queue[ label = "Queue" style = filled fillcolor = "green"]
		{rank = same; producer; master_thread}
		{rank = same; consumer; worker_thread}
		{rank = same; Queue; client_socket}
	}

	request1 -> master_thread[color = "red"]
	request2 -> master_thread[color = "red"]
	request3 -> master_thread[color = "red"]
	// 边是虚线，且是橙色
	request1 -> worker_thread : w0 [ style = "dashed" color = "orange", label = "process request"]
	request2 -> worker_thread : w1 [ style = "dashed" color = "orange" label = "process request"]
	request3 -> worker_thread : w2 [ style = "dashed" color = "orange" label = "process request"]

        Browser[ label = "Browser" style = filled fillcolor = "green"]
	{rank = same; Browser; request1; request2; request3}

}

    结果：

    多个点相互连接的简便写法是
{a; b} -> {c; d}

双向边：https://blog.youkuaiyun.com/csfreebird/article/details/50991993

参考
http://gashero.iteye.com/blog/1748795