Simple bash loading animation

#bash #terminal #devops #development

I was looking for a simple way to achieve a basic load icon that ticks after a piece of text in bash, but there was noting I could just easily copy paste. Now I'll provide one for you, no shenanigans, no messing around.

Short story

I've found this one, Silejonu's solution on Github but this is rather a module than something you can copy paste, and sometimes you don't want to add whole dependencies, just a piece of logic.

So here it is:



function loading_icon() {

    local load_interval="${1}"

    local loading_message="${2}"

    local elapsed=0

    local loading_animation=( '—' "\" '|' '/' )

<span class="nb">echo</span> <span class="nt">-n</span> <span class="s2">"</span><span class="k">${</span><span class="nv">loading_message</span><span class="k">}</span><span class="s2"> "</span>

<span class="c"># This part is to make the cursor not blink</span>
<span class="c"># on top of the animation while it lasts</span>
tput civis
<span class="nb">trap</span> <span class="s2">"tput cnorm"</span> EXIT
<span class="k">while</span> <span class="o">[</span> <span class="s2">"</span><span class="k">${</span><span class="nv">load_interval</span><span class="k">}</span><span class="s2">"</span> <span class="nt">-ne</span> <span class="s2">"</span><span class="k">${</span><span class="nv">elapsed</span><span class="k">}</span><span class="s2">"</span> <span class="o">]</span><span class="p">;</span> <span class="k">do
    for </span>frame <span class="k">in</span> <span class="s2">"</span><span class="k">${</span><span class="nv">loading_animation</span><span class="p">[@]</span><span class="k">}</span><span class="s2">"</span> <span class="p">;</span> <span class="k">do
        </span><span class="nb">printf</span> <span class="s2">"%s</span><span class="se">\b</span><span class="s2">"</span> <span class="s2">"</span><span class="k">${</span><span class="nv">frame</span><span class="k">}</span><span class="s2">"</span>
        <span class="nb">sleep </span>0.25
    <span class="k">done
    </span><span class="nv">elapsed</span><span class="o">=</span><span class="k">$((</span> elapsed <span class="o">+</span> <span class="m">1</span> <span class="k">))</span>
<span class="k">done
</span><span class="nb">printf</span> <span class="s2">" </span><span class="se">\b\n</span><span class="s2">"</span>



    

    




}

loading_icon 60 "I'm loading!"

And here's what it looks like:

Limitations

Shows a given loading_message and after it a small loading icon for the provided load_interval seconds.
After the provided time elapsed the last character of the loading icon is erased and a new line is started (this can be changed by updating printf " \b\n").

You can get more animation ideas from Silejonu, bash_loading_animations file, all you have to do is to replace the loading_animation variable in the script (don't forget to remove the first element, the interval number).

Enjoy! ^^