shell判断文件后缀是否为zip

function IsSuffix() {
    filename=$1
    fileSuffix=${filename##*.}
    if [ ${fileSuffix} != "zip" ]; then
        echo -e "\033[36mSecond parameter error, must be xxx.zip. \033[0m"
        show_help
        exit
    fi
}
IsSuffix $filename