function 函数

#!/bin/bsh

function echo_color() {
    if [ $1 == "green" ]; then
        echo -e "033[32;40m$2033[0m"
    elif [ $1 == "red" ]; then
        echo -e "033[31;40m$2033[0m"
    fi
}

echo_color green "test_green"
echo_color red "test_red"

#!/bin/bash

log() { # classic logger
    local prefix="[$(date +%Y/%m/%d %H:%M:%S)]: "
    echo "${prefix} [email protected]" >&2
}

log "INFO" "a message"

>>>
[2019/06/18 13:35:30]:  INFO a message