练习_(if、case)多系统配置yum源

#!/usr/bash/bin
yum_server=192.168.201.130
os_version=`cat /etc/redhat-release | awk '{print $4}' | awk -F"." '{print $1"."$2}'`

[ -d /etc/yum.repos.d] || mkdir /etc/yum.repos.d/bak
mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak


if [ "$os_version"="7.3" ];then
        cat > /etc/yum.repos.d/centos7u3.repo <<-EOF
        [centos7u3]
        name=centos7u3
        baseurl=ftp://$yum_server/centos7u3
        gpgcheck=0
        EOF
        echo "7.3 yum configure.."
elif [ "$os_version"="6.8" ];then
        curl -o /etc/yum.repos.d/centos6u8.repo ftp://$yum_server/centos6u8
else
        echoo "error"
fi

case格式：
	case 变量 in 
	模式1)
		命令序列1
		;;
	模式2)
		命令序列2
		;;
	*)
		无匹配后命令序列
	esac

#!/usr/bash/bin
yum_server=192.168.201.130
os_version=`cat /etc/redhat-release | awk '{print $4}' | awk -F"." '{print $1"."$2}'`

[ -d /etc/yum.repos.d] || mkdir /etc/yum.repos.d/bak
mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak

case $os_version in
7.3)
	cat > /etc/yum.repos.d/centos7u3.repo << EOF
			[centos7u3]
			name=centos7u3
			baseurl=ftp://$yum_server/centos7u3
			gpgcheck=0
	EOF
	echo "7.3 yum configure.."
	;;
6.8)
	curl -o /etc/yum.repos.d/centos6u8.repo ftp://$yum_server/centos6u8
	;;
*)
esac