Port of the week: entr

• Author: Solène
• Date: 07 January 2017
• Tags: unix

NILentr 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.