This is a loose translation of my post from 2017
Recently, I was looking for a one-liner to start a web-server in the current directory. Stack Overflow gave me this command:
So what is this mysterious
-run option an why is it not in the ruby manual?
-run is not an option. More precisely, it’s an option, but not
“run”. Notice that there’s one dash instead of two.
Turns out, it’s just an option
-r with an argument
un is a file in
ruby standard library (2023 edit: now available on Github). It defines a few
useful methods to use in one-liners as standalone programs.
One of the methods is
httpd which just start
WebBrick with parameters from
ARGV (in the case above, it’s just port and directory).
Apparently, it’s a really old file beceause I found its documentation for ruby
1.8.6. So you can use it freely.
What else is in there?
Here’s a copypaste from the docs:
I think there’s not much point in using
un outside of one-liners since its
every method uses
ARGV but it’s useful to remember that ruby has it. I imagine
it’ll work in Windows too bringing a way to use Unix-tools in it.
BTW, I added this alias to my bash config: