linux - "No Output"返回代码 Shell 脚本

Question

我正在尝试创建一个脚本来终止进程并在发出 kill -9 命令之前确认进程正在运行，但我遇到了一个错误，它总是假设有输出。

#!/bin/sh
rc=$?

#Ask to check for a process to kill
clear
echo "Please enter a process number you would like to kill"
echo ""
read proc
ps -ef | awk '{print $2}' | grep *$proc*
if [[ $rc != 0 ]]; then
        echo "Process not running or already killed"
        sleep 2
        exit $rc
else
        clear
        echo "Killing process..."
        sleep 2
#       kill -9 $proc
fi

Answer 1

使用 grep $proc 是错误的。如果你想杀死PID 22，它将匹配122，220等

测试 PID 是否存在的最简单方法是尝试向其发送信号 0:

if kill -0 "$proc" 2>/dev/null
then
    clear
    echo "Killing process..."
    sleep 2
    kill -9 "$proc"
else
    clear
    echo "Process not running or already killed"
    sleep 2
    exit 1
fi

Signal 0 不执行任何操作，它只是测试您是否能够向该进程发送信号。