Last week, We Wish You a Merry Christmas was playing somewhere, an idea came to me, what if your computer sings one note on every key you press? That would be fun, wouldn’t it?

And here is the merryxmas.sh and a video to demonstrate.

https://i.ytimg.com/vi/D1gXN7wZ7IM/maxresdefault.jpg

1   About the code

I decided to write it entirely in Bash with some tools, such as xinput and play from Sox.

I could have forked the xinput to modify and strip it for this purpose, it would be cleaner since I really don’t have any idea how to handle the buffer issue1. But with shell scripting, it’s easier to modify if there are suitable tools.

Originally, I was going for only keyboard presses, but then I added mouse clicks, and then the movements. It turned out pretty nice.

As for xinput and its test, unfortunately, it can only monitor one device and you also need to specify the device name. I needed to get both keyboard and mouse events in altogether at the same time, I tried to use mkfifo, but that didn’t work, so I resolved with regular files and those would increase in file size.

Its test-xi2 works for all input devices, but it pops up a window like xev and that wouldn’t be a good surprise for your family and friends, right?

The choice of sound playing is play from Sox, which I don’t believe many computer would have it, but at least it’s included in almost all distributions’ package managers. I could go with wave, but you would have to download and compile it. But it might be a better option, because I doubt anyone would have your target’s computer’s password to gain root access for using package manager to install Sox

[1]As you are required to run with stdbuf, without it, due to the buffer size, you will have to press a lot to get the song singing.

2   Some ideas

This script is just a basic one. I could think of a few more that you can wish your family and friends:

  1. Run Xsnow while or after playing.
  2. Pop up a message box or using xdotool2 to type in the message.
  3. Only play a note when hitting one of “xmas” or “christmas” keys.
  4. Play the whole song at once if “xmas” or “christmas” is exactly spelled.

I personally, like 1 and 4, especially 4, because during this holiday season, you can be sure the chance that a user would type the word in is very high, almost unavoidable. They can be writing an email to family and friends, just as typing in the subject line, the computer sings. Wouldn’t that be fun?

[2]I use xdotool to enter timestamp.