Make your terminal snow

snowjob.sh

#!/bin/bash

LINES=$(tput lines)
COLUMNS=$(tput cols)

declare -A snowflakes
declare -A lastflakes

clear

function move_flake() {
    i="$1"

    if [ "${snowflakes[$i]}" = "" ] || [ "${snowflakes[$i]}" = "$LINES" ]; then
        snowflakes[$i]=0
    else
        if [ "${lastflakes[$i]}" != "" ]; then
            printf "\033[%s;%sH \033[1;1H " ${lastflakes[$i]} $i
        fi
    fi

    printf "\033[%s;%sH*\033[1;1H" ${snowflakes[$i]} $i

    lastflakes[$i]=${snowflakes[$i]}
    snowflakes[$i]=$((${snowflakes[$i]}+1))
}

while :
do
    i=$(($RANDOM % $COLUMNS))

    move_flake $i

    for x in "${!lastflakes[@]}"
    do
        move_flake "$x"
    done

    sleep 0.1
done

If your terminal font supports it you can replace * at line 22 with ❄ to make it more festive

Can you make it appear on top of something that's already running?

awesome!

I named the script as snowjob, and this is the output?
snowjob: 11: Syntax error: "(" unexpected

Like it!

@allaun What shell are you using? You can replace function move_flake() with function move_flake (removing the parens) and it'll work for you

Nice. Also you can rotate different flake glyphs if you replace * with \u274"$[($RANDOM%6)+3]"

@EmbeddedLinuxGuy That is awesome, thanks!

cool!

Thanks for the script it is very cool, but could you provides us with some additional info about how to make it more functional ... for example how to make the snow appear on a functional terminal screen as @amstan stated in his comment. I am new with bash scripting and want to use your code to decorate a script I am creating but I can not deduce where to put my code... thanks

@amstan @blottis
I've also been trying to get the snow effect as a background on my running terminal. I don't think this is possible without some major refactoring in the bash script as the print out to stdout would collide with normal terminal function use.

In case you are like me and found this post years later, many modern terminals now have built in functionality for effects. I've been using Windows Terminal to get the desired snow effect I want.

Yeah, the only way to get the effect during usage is built-in features of the terminal like shaders and stuff like what you did for the windows terminal. This is a generic / cross platform way of getting effects that doesn't depend on the shell at all

snowflakes are not coming for me

hmmm unclear what the expected effect is meant to be 🤔

Same issue

@heyarviind @alaz-aura @sandippingle the previous revision works: https://gist.github.com/sontek/1505483/ed3449161c88f3ca5f96c1286009fc68d326d4e8

Yea new revision doesnt work for me either but old revision works great

Wow, interesting that others are finding this today. I've done a lot of work on this over the years and its currently packaged over here:

https://github.com/sontek/snowmachine

I think people are finding it through a python implementation that got to hackernews front page https://news.ycombinator.com/item?id=38652339

Oh thats also yours hahaha @sontek

For people on MacOS that the new version isn't working on, it's due to the bash version shipping with macOS being too old to support unicode escape.

If you have a newer version of bash installed in homebrew you can change the bang at the top e.g. #!/opt/homebrew/bin/bash (or use the author's python version)

snowflakes are not coming for me

You cut too much in your snowflake paste. Change line 22 to printf "\033[%s;%sH❄\033[1;1H" ${snowflakes[$i]} $i

This is what I get on MacOS iTerm2. Is this supposed to be it! I was expecting SNOW flakes xD.

With ❄

Thanks the updates everyone, snow has been fixed!