URI: 

       Title: Port of the week: entr
       Author: Solène
       Date: 07 January 2017
       Tags: unix
       Description: 
       
       **entr** is a command line tool that let you run arbitrary command on
       file change. This is useful when you are doing something that requires
       some processing when you modify it. 
       
       Recently, I have used it to edit a man page. At first, I had to run
       mandoc each time I modified to file to check the render. This was the
       first time I edited a man page so I had to modify it a lot to get what
       I wanted. I remembered about **entr** and this is how you use it:
       
           $ ls stagit.1 | entr mandoc /_
dataswamp.org:70 /~solene/article-entr:17: port field too long