Title : Port of the week: entr
Author: Solène
Date  : 07 January 2017
Tags  : unix

**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 /_
	
This simple command will run "mandoc stagit.1" each time stagit.1 is
modified. The file names must be given by stdin to entr, and then use
the characters sequence **/_** to replace the names (like {} in find).

The man page of entr is very well documented if you need more
examples.