shell示例（二）

简介

shell示例总结。

shell脚本示例

示例1：编写一个操作文件的脚本，如下所示：

---

***1.backup **
***2.copy **
***3.quit **

---

input a choice:

代码：

#!/bin/bash
cat<<eof

*******************

***1.backup **
***2.copy   **
***3.quit   **

*******************

eof
read -p "input a choice:" ot
 case $ot in
  1|backup)
        echo "backup....."
        ;;
  2|copy)
        echo "copy....."
        ;;
  3|quit)
        exit
        ;;
  *)
        echo "please input 1-3|backup|copy|quit"
 esac

示例2 ：编写一个启动 apache 服务脚本

代码：

#!/bin/bash
case $1 in
 start)
        /usr/bin/systemctl $1 httpd
        /usr/bin/ps aux |grep httpd >/dev/null 2>&1
        echo "httpd start"
        ;;
 stop)
        /usr/bin/systemctl $1 httpd
        /usr/bin/ps aux |grep httpd >/dev/null 2>&1
        echo "httpd stop"
        ;;
 restart)
        echo "httpd stop"
        /usr/bin/systemctl stop httpd
        /usr/bin/ps aux |grep httpd >/dev/null 2>&1
        echo "httpd start"
        /usr/bin/systemctl start httpd
        /usr/bin/ps aux |grep httpd >/dev/null 2>&1
        ;;
 status)
        /usr/bin/systemctl $1 httpd
        /usr/bin/ps aux |grep httpd >/dev/null 2>&1
        echo "httpd status"
        ;;
 *)
        echo "please input start|stop|restart|status"
esac

示例3：#指定以\n 回车作为分隔符输出/etc/hosts

代码：

#!/bin/bash
IFS=$'\n'
list=`cat /etc/hosts`
for i in $list
do
 echo "$i"
done

示例4：降序输出 10 到 1 的数字

代码:

#!/bin/bash
var=10
while [ $var -gt 0 ]
do
 echo "$var"
 var=$[$var-1]

done

示例5：实现以下效果

1 * 1 = 1
2 * 2 = 4
3 * 3 = 9
4 * 4 = 16
5 * 5 = 25
6 * 6 = 36
7 * 7 = 49
8 * 8 = 64
9 * 9 = 81

代码：

#!/bin/bash
num=1
while [ $num -lt 10 ]
do
 sum=$[ $num * $num ]
 echo "$num * $num = $sum"
 num=$[ $num + 1]
done

示例6：批量添加 a.txt 文件 5 个用户

代码：

#!/bin/bash
list=`cat /root/test/a.txt`
for i in $list
do
 id $i &>/dev/null
 if [ $? -ne 0 ];then
        useradd -M $i
        echo "12345"|passwd --sdin $i &>/dev/null
        echo "$i is created"
 else
        echo "$i is exist"
 fi
done

示例7：批量创建帐号并生成随机密码

代码：

#!/bin/bash
[ -f /tmp/passwd.txt ]||touch /tmp/passwd.txt
for i in a{1..10}
do
 useradd $i
 pass=$(date +%s | md5sum |cut -c 1-8)
 sleep 1
 echo $i:$pass >>/tmp/passwd.txt
 echo $pass|passwd --stdin $i
 if [ $? -eq 0 ];then
        echo "user $i create successfully"
 else
        echo "user $i create failly" 
 fi
done

示例8：打印九九乘法表

代码：

#!/bin/bash
for i in `seq 9`
do
 for j in `seq $i`
 do
        echo -n "$i*$j=`echo $[$i * $j]` "

 done
 echo " "
done

示例9：监控httpd服务自动启动并记录

代码：

#!/bin/bash
while true
do
 port=$(nmap -sT 192.168.130.63| grep tcp | grep -w http |awk '{print $2}')
 if [ $port == "open" ];then

        echo "$(date) httpd service is opening!">>/tmp/autostart-acc.txt
 else
        /usr/bin/systemctl start httpd &>/dev/null
        echo "$(date) httpd service restart!">>/tmp/autostart-err.txt
 fi
 sleep 60
done

注：

nmap -sT TCP connect()扫描,这种方式会在目标主机的日志中记录大批的连接请求以及错误信息

grep -w 精确匹配

示例10：将/opt 目录下所有的日志文件全自动打包

代码：

#!/bin/bash
DEC_DIR=/opt/`date +%Y-%m-%d`
SRC_DIR=/opt
logname=$(find $SRC_DIR -name *.log)
if [ ! -d $DEC_DIR ];then
        mkdir -p $DEC_DIR
fi
cd $SRC_DIR
for i in $logname
do
tar -zcf opt.tar.gz $i
done
mv $SRC_DIR/*.tar.gz $DEC_DIR
ls $DEC_DIR>/dev/null 2>&1
echo "the scripts exec end,file back successfully!"  

示例11：找出 192.168.130.1-10 网段中，服务器已经关机的 IP 地址

#!/bin/bash
for i in `seq 10`
do
 ping -c 192.168.130.$i>/dev/null 2>&1
 if [ $? -ne 0 ];then
        echo "192.168.130.$i is shutdown"
 fi
done