A simple script to show a spinner during long tasks in bash

bashSpinner.sh

#!/bin/bash

###
# Author:       github.com/Pandry
# Version:      v1.0
# Description:  A simple function to create a spinner while executing a long command
#                  You can easily add your spinner by putting every "frame" into the spinarr array :)
###

spinner()
{
    local -a spinarr=('⊶ ' '⊷ ')
    local delay=0.25
    
    #Some other spinners from the awesome sindresorhus' cli-spinners (https://github.com/sindresorhus/cli-spinners)
    #local -a spinarr=('⣾' '⣽' '⣻' '⢿' '⡿' '⣟' '⣯' '⣷')
    #local -a spinarr=('⢀⠀' '⡀⠀' '⠄⠀' '⢂⠀' '⡂⠀' '⠅⠀' '⢃⠀' '⡃⠀' '⠍⠀' '⢋⠀' '⡋⠀' '⠍⠁' '⢋⠁' '⡋⠁' '⠍⠉' '⠋⠉' '⠋⠉' '⠉⠙' '⠉⠙' '⠉⠩' '⠈⢙' '⠈⡙' '⢈⠩' '⡀⢙' '⠄⡙' '⢂⠩' '⡂⢘' '⠅⡘' '⢃⠨' '⡃⢐' '⠍⡐' '⢋⠠' '⡋⢀' '⠍⡁' '⢋⠁' '⡋⠁' '⠍⠉' '⠋⠉' '⠋⠉' '⠉⠙' '⠉⠙' '⠉⠩' '⠈⢙' '⠈⡙' '⠈⠩' '⠀⢙' '⠀⡙' '⠀⠩' '⠀⢘' '⠀⡘' '⠀⠨' '⠀⢐' '⠀⡐' '⠀⠠' '⠀⢀' '⠀⡀')
    #local -a spinarr=('⠁' '⠉' '⠙' '⠚' '⠒' '⠂' '⠂' '⠒' '⠲' '⠴' '⠤' '⠄' '⠄' '⠤' '⠴' '⠲' '⠒' '⠂' '⠂' '⠒' '⠚' '⠙' '⠉' '⠁')
    #local -a spinarr=('◢' '◣' '◤' '◥')
    #local -a spinarr=('▹▹▹▹▹' '▸▹▹▹▹' '▹▸▹▹▹' '▹▹▸▹▹' '▹▹▹▸▹' '▹▹▹▹▸')
    #local delay=0.1
    
    
    local i=0
    while [ "$(ps a | awk '{print $1}' | grep $1)" ]; do
        local str=" ${spinarr[$(( $i % ${#spinarr[@]} ))]} $2"
        printf "%s" "$str"
        i=$(($i+1))
        sleep $delay
        for (( j=0; $j < ${#str}; j++ )); do printf "\b"; done;
    done
    for (( j=0; $j < ${#str}; j++ )); do printf "\b"; done;echo;
}

# Usage example (just copy&paste into a file, then chmod +x and execute):
sleep 10 && echo 'Hello world!' &
spinner $! "Calculating the string..."