shell中case语句练习

示例2：

[root@linux-server script]# vim system_tools.sh
#!/usr/bin/env bash
cat <<-EOF 
+-------------------------------------------------------------------------+ 
|                             System_tools V1.0                           | 
+-------------------------------------------------------------------------+
|                     a. Stop And Disabled Firewalld.                     |
|                     b. Disabled SELinux Secure System.                  |
|                     c. Install Apache Service.                          |
|                     d. Quit                                             | 
+-------------------------------------------------------------------------+ 
EOF
echo "Please input your select: " && read var
case "$var" in
    "a")
        systemctl stop firewalld && systemctl disable firewalld
                ;; 
        "b")
                setenforce 0
                ;; 
        "c")
                yum -y install httpd httpd-tools
                ;; 
        "d")
                exit
                ;; 
            *)
                printf "请按照上方提供的选项输入!!!\n"
                ;; 
esac
[root@linux-server script]# chmod +x system_tools.sh
[root@linux-server script]# ./system_tools.sh

练习:
1.建立脚本service.sh,当执行的时候要求输入(1、2、3、4、5)时安装对应的httpd、vim、wget、更换aliyum等功能，当输入错误 时会提示你，应该输入正确的值。