Shell脚本实用案例-优快云博客

作业的处理

1 用户录信息显示用户登录次数登录四次就提醒不到四次就睡眠5s

#!/bin/bash

14 cut -d: -f1 /etc/passwd | grep "^$1" &>/dev/null || exit 3
15   let conut=`who | grep "^$1" | wc -l`
16    if [ $conut -le 4 ] ;then
17        sleep 3
18   else
19         echo "$1 login 4 times"
20    fi

另一种方法：

5 cut -d: -f1 /etc/passwd | grep "^$1" &>/dev/null || exit3

6 let count=`who | grep "^$1" | wc -l `

  7 until [ $count -ge 4 ] ; do
8     sleep 2
9 let count=`who| grep "^$1" | wc -l`
10 done
11    echo "$1 have been login 4 times"

2 用户登录显示所使用的shell类型

3 三个数的大小比较

4 100的偶数的和

5 判断文件是否存在并显示文件行数

6 ping C类网络

#!/bin/bash

ping() {

20       read -p "ip:" mip
21 PINGNET=`echo $mip | sed 's/$[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}$.*/\1/g'`
22
23     let I=1
24     while [ $I -le 20 ]; do
25       ping -c1 -W1 $PINGNET.$I &> /dev/null
26    [ $? -eq 0 ] && echo -e "\033[32m$PINGNET.$I online.\033[0m" || echo -e "\033[        31m$PINGNET.$I offline.\033[0m"
27       let I++
28     done
29 }
31   ping

显示结果加上颜色可以echo -e "\033[31(代表颜色值)PINGNET.$I on line.\033[0m"

7 eth0网卡的编辑和替换

1 #!/bin/bash
2 #auther:jing
3 #date: 11:56:26 2011-01-13
4 #dese:
5 read -p "iput ip:" myip
6 read -p "iput mask:" mask
7 file=/root/jing/ifcfg-eth0
8 if grep -E "^BOOTPROTO=(dhcp)|(bootp)$" $file &>/dev/null ;then
9          sed -i " s/^BOOTPROTO=.*/BOOTPROTO=staic/g" $file
10         grep "^IPADDR=.*" $file &>/dev/null && sed -i "s/IPADDR=.*/IPADDR=$myip/g" $file || sed -i  "/BOOTPROTO=.*/a\IPADDR=$myip" $file
11         grep "^NETMASK=.*" $file &>/dev/null && sed -i "s/NETMASK=.*/NETMASK=$mask/g" $file || sed -i "/IPADDR=.*/a\NETMASK=$mask" $file
12 fi

要求用户输入ip和子网掩码判段/root/ifcfg-eth0 的bootproto值并将其值替换成static 然后查找文件中是否有IPADDR和NETMASK字段如果有就将其改为自己设的$MY、$MYMASK 没有的话就添加自己的设置的$MY、$MYMASK

扩展

   1 #!/bin/bash
2 #auther:jing
3 #date: 11:56:26 2011-01-13
4 #dese:
5 read -p "iput ip:" myip
6 [ -z $myip ] && myip='192.168.0.50'
7 read -p "iput mask:" mask
8 [ -z $mask ] && mask='255.255.255.0'
9 file=/root/jing/ifcfg-eth0
10 if grep -E "^BOOTPROTO=(dhcp)|(bootp)$" $file &>/dev/null ;then
11     sed -i " s/^BOOTPROTO=.*/BOOTPROTO=staic/g" $file
12      grep "^IPADDR=.*" $file &>/dev/null && sed -i "s/IPADDR=.*/IPADDR=$myip/g" $file || sed -i "/BOOTPROTO=.*/a\IPADDR=$myip" $file
13    grep "^NETMASK=.*" $file &>/dev/null && sed -i "s/NETMASK=.*/NETMASK=$mask/g" $file || sed -i "/IPADDR=.*/a\NETMASK=$mask" $file
14 fi

在作业7的基础上扩展判断用户输入的ip和子网掩码是否合法并在用户不输入的情况下系统给出默认的ip和掩码

扩展二

4 #!/bin/bash
5 file=/root/jing/ifcfg-eth0
6 read -p "iput ip:" myip
7     [ -z $myip ] && myip='192.168.0.50'
8      echo "choice a netmask: [1 2 3]"
9      cat <<EOF
10    1   255.255.255.0
11     2   255.255.0.0
12    3   255.0.0.0
13 EOF
14 read choice
15     case $choice in
16   1) mask= 255.255.255.0 ;;
17   2) mask=255.255.0.0 ;;
18   3) mask=255.0.0.0 ;;
19   *)
20   [ -z $choice ] && read -p "input your mask:" mask || mask='255.255.255.0'
21   ;;
22 esac
23 if grep -E "^BOOTPROTO=(dhcp)|(bootp)$" $file &>/dev/null ;then
24       sed -i " s/^BOOTPROTO=.*/BOOTPROTO=static/g" $file
25      grep "^IPADDR=.*" $file &>/dev/null && sed -i "s/IPADDR=.*/IPADDR=$myip/g" $file || sed -i "/BOOTPROTO=.*/a\IPADDR=$myip" $file
26      grep "^NETMASK=.*" $file &>/dev/null && sed -i "s/NETMASK=.*/NETMASK=$mask/g" $file || sed -i "/IPADDR=.*/a\NETMASK=$mask" $file
27 fi