Real bash loader. Result : https://www.youtube.com/watch?v=ff7SQ0y-Sng

bash-loader.sh

#
#  From Antonin Hérault
#  https://github.com/antoninhrlt
#

function bash-loader()
{
    if [[ -z $1 ]]
    then
        local text="undefined text"
    else
        local text=$1
    fi

    if [[ -z $2 ]]
    then
        local sp=". "
    else
        local sp=$2
    fi

    PID=$!
    local i=1
    echo -n " "

    while [ -d /proc/$PID ]
    do
        printf "\r${text} ${sp:i--%${#sp}:1} ${sp:i++%${#sp}:1} ${sp:i--%${#sp}:1}\t"
        sleep .3 # Does not affect the execution time in any way!
    done
}

# _____________________________________________________________________________________

# Usage :

    # your command here &
    bash-loader "My text"

# or (to change symbol)

    # your command here &
    bash-loader "My text" " # "

# Example :

    echo "Start compile"
    g++ src/main.cpp -o bin/prog & # Don't forget "&" symbol !
    bash-loader "Compilation"
    echo -e "\nFinish !"