POSIX Spin Function

spin() {
    sp="/-\|"
    printf " "
    sleep 0.2
    while true; do
        printf "\b%.1s" "$sp"
        sp=${sp#?}${sp%???}
        sleep 0.2
    done
}

#!/bin/sh

spin() {
    .
    .
    .
}

printf "Hacking NASA    "
spin &
spinpid=$!
trap 'kill $spinpid' SIGTERM SIGKILL
{
    # You can run all the command you want here. I will only run sleep command.
    sleep 5
} >/dev/null 2>&1
kill $spinpid
printf "\b \t[done]\n"
printf "NASA has been successfully hacked!!!\n"

exit 0