demo_script.sh

#!/bin/bash

PROMPT="\n$ "
DELAY_COMMENT_CHAR="0.1s"
DELAY_COMMENT="1s"
DELAY_RUN="3s"

GRAY="\033[1;30m"
LIGHT_GRAY="\033[0;37m"
CYAN="\033[0;36m"
LIGHT_CYAN="\033[1;36m"
NO_COLOR="\033[0m"

function prepare {
    for i in {3..1}; do
        printf "%c..." $i
        sleep 1s
    done
    clear
    printf "${PROMPT}"
    sleep 1s
}

function comment {
    local msg="$1"

    printf "${LIGHT_CYAN}"
    for i in $(seq 0 ${#msg}); do
        printf "%c" "${msg:$i:1}"
        sleep "${DELAY_COMMENT_CHAR}"
    done
    printf "${NO_COLOR}\n${PROMPT}"
    sleep "${DELAY_COMMENT}"
}

function run {
    local cmd="$1"

    printf "%s\n" "${cmd}"
    sleep "${DELAY_RUN}"
    eval "${cmd}"
    printf "${PROMPT}"
}

prepare
comment '# JSONTest.com is a testing platform for services utilizing JavaScript Object Notation (JSON)'
run 'curl --silent http://headers.jsontest.com | jq -C'