nohup java -jar app.jar > /dev/null 2>&1 & 解释一下这个命令

&1 &

This command runs a Java application in the background using the nohup command. The output of the application is redirected to /dev/null, which discards it. The 2> redirects any error messages to the same location as the output. The &1 & at the end of the command puts the process in the background and detaches it from the terminal, allowing it to continue running even if the terminal is closed.

相关问题

nohup java -jar app.jar > /dev/null 2>&1 &

&1 &

This command starts a Java application in the background, redirects standard output to /dev/null (which discards it), redirects standard error to standard output, and detaches the process from the terminal by using nohup and &. This allows the application to continue running even if the terminal is closed, and prevents it from being terminated by the HANGUP (SIGHUP) signal.

写一个shell脚本判断curl -o /dev/null -s -w %{http_code} http://192.168.0.173/riskWeb/secureBaseApp/tenant/tenantByUser的返回值是否等于200，等于的话，输出$(date "+%Y-%m-%d_%H:%M:%S"), cyb-secureBase" is running"，如果不等于去判断pid=`ps -ef | grep /app/service/cyb-secureBase/app.jar | grep -v grep | awk '{print $2}'是否有值输出，有的话echo $(date "+%Y-%m-%d_%H:%M:%S"), cyb-secureBase" is running"，没有执行nohup java -Xms256m -Xmx1024m -Xmn256m -Dfile.encoding=utf-8 -jar /app/service/cyb-secureBase/app.jar > app.log 2>&1 &

可以参考下面的Shell脚本来实现你的需求：

#!/bin/bash

# 发送GET请求，并获取返回状态码
response_code=$(curl -o /dev/null -s -w "%{http_code}" http://192.168.0.173/riskWeb/secureBaseApp/tenant/tenantByUser)

# 判断返回状态码是否等于200
if [ $response_code -eq 200 ]; then
    echo "$(date "+%Y-%m-%d_%H:%M:%S"), cyb-secureBase is running"
else
    # 判断进程是否存在
    pid=$(ps -ef | grep /app/service/cyb-secureBase/app.jar | grep -v grep | awk '{print $2}')
    if [ -n "$pid" ]; then
        echo "$(date "+%Y-%m-%d_%H:%M:%S"), cyb-secureBase is running"
    else
        nohup java -Xms256m -Xmx1024m -Xmn256m -Dfile.encoding=utf-8 -jar /app/service/cyb-secureBase/app.jar > app.log 2>&1 &
    fi
fi

将以上代码保存为脚本文件（比如`check_service.sh`），然后通过`chmod +x check_service.sh`添加执行权限。运行脚本`./check_service.sh`即可完成判断和执行操作。