How can Homebrew print a beer mug in Terminal?

Question

Homebrew has a neat trick of printing out little icons next to its output. Like this:

If I copy paste the icon it on its own and hit enter I get the result:

-bash: $'?\237\215?': command not found

And if I try it with echo or printf I just get ????. Same if I escape all the quotes and $s etc.

editron:~ stib$ echo $'?\237\215?'
????

So how do they do that? What do the magic characters $'?\237\215?' mean?

Answer 1

Homebrew is open source, so you can read its code to find out how it shows the icon. The line they're using is in the file formula_installer.rb:

print "🍺  " if MacOS.version >= :lion

The first character in the print command is a "🍺", or unicode #1f37a 'BEER MUG'.

So it's not an icon but an funny unicode beer mug :)

Answer 2

BTW, try another variants in terminal:

echo $'\360\237\215\270'
echo $'\360\237\215\271'
echo $'\360\237\215\273'
echo $'\360\237\215\274'