识别CentOS和Ubuntu的系统版本

识别CentOS和Ubuntu的系统版本

1、用 lsb-release

#!/bin/bash
Install_LSB()
{
        if [ "$PM" = "yum" ]; then
                yum install -y redhat-lsb centos-release
        elif [ "$PM" = "apt" ]; then
                apt-get update
                apt-get install -y lsb-release
        fi
}
Install_LSB
lsb_release -d

2、从定义好的配置文件中读取

CentOS 中相关的文件
cat /etc/centos-release
cat /etc/redhat-release (/etc/redhat-release -> centos-release)
cat /etc/system-release (/etc/system-release -> centos-release)
rpm -q centos-release
# rpm -q redhat-release
如果是CentOS7，支持 cat /etc/os-release

Ubuntu 中相关的文件
cat /etc/os-release  (/etc/os-release -> ../usr/lib/os-release)
cat /etc/lsb-release

在CentOS和Ubuntu中也可以这样读系统版本，不过 /etc/issue (登录欢迎信息)有时候是空的
cat /etc/issue
#cat /etc/*elease
for i in $(ls /etc/*release); do echo ===$i===; cat $i; done

3、hostnamectl

在CentOS7和Ubuntu中，通过 hostnamectl 读系统版本
hostnamectl

Ubuntu中这样安装 hostnamectl
apt install -y systemd systemd-services apt-file
apt-file update
apt-file search hostnamectl
/usr/bin/hostnamectl