linux - 解析而不解析标志和参数时回显信息

#function:      usage
#description:   1. parse command line arguments
#               2. for illegal usages, print usage message and exit 1
#               3. otherwise, communicate to main() what flags are set

function usage {
while getopts ":gn:" OPT; do
    case $OPT in
            g) ;;
            n) name=$OPTARG;;
            :) echo "$USAGE"
               exit 1
            ;;
            \?) echo "$USAGE"
                exit 1
            ;;
            *) echo "$USAGE"
               exit 1
        esac
done


shift $(($OPTIND + 1))
}

#function:      main
#description:   For Part 1:
#               1. use usage() to parse command line arguments
#               2. echo corresponding messages for each flag that is set
#
#               For Part 2:
#               Kill processes based on the case return by `usage`


function main {

# TODO change the condition so that this line prints when '-g' is set
    usage()
if [ ! -z "g" ]; then
    echo graceful kill is present
fi

# TODO change the condition so that this line prints when '-n' is set
if [ ! -z "n" ]; then
    echo process name is present
fi
main $@

这就是我写的，我想
./KillByName-g 24601
优雅的杀戮
或
./KillByName-g
用法：KillByName[-g]-n或KillByName[-g]
或
./KillByName-g-n巴什
优雅的杀戮
存在进程名
从本质上讲，如果存在-g，则表明它被优雅地杀死了，并且有一个名字。如果有-n，那么它表示名称退出并以名称命名。
我发现我的脚本可以打印优雅的kill present或name present的消息，但不能打印$USAGE的错误。
顺便说一句：这只是为了提供使用信息，而不是真正的程序终止程序

最佳答案

首先，

usage()

不是你调用函数的方式，应该是

usage

但是有一个问题，您没有将任何参数从usage传递给函数main，所以它应该

usage "$@" # Double quotes to prevent word splitting

虽然“优雅的杀戮”这个词本身就是一个悖论，但是你可以做一些类似的事情

while getopts ":gn:" OPT; do
gracekill=0; //s
case $OPT in
        g) gracekill=1;;
        n) name=$OPTARG;;
        :) echo "$USAGE"
           exit 1
        ;;
        \?) echo "$USAGE"
            exit 1
        ;;
        *) echo "$USAGE"
           exit 1
    esac
    done
    echo "$gracekill $name" # Mind double quotes

然后执行以下操作：

result=$(usage "$@")
if [ ${result:0:1} -eq '1' ]
then
#gracefully kill the application
kill -9  $( pgrep "${result:1}" )
else
#ruthlessly terminate it
kill -15 $( pgrep "${result:1}" )
fi

有关${var:offset:length}表单的更多信息，请参见[ param expansion ]
注意：我假设您将进程名传递给函数，如果传递的是进程号，则不需要
pgpepiekill -15 $( pgrep "${result:1}" )将变成kill -15 "${result:1}"等等。祝你好运！