bash脚本编程之八 until及脚本完成磁盘分区格式化

until condition; do

statement

...

done

进入循环：条件不满足

退出循环：条件满足

#!/bin/bash

#

read -p "Input something:" STRING

until [ $STRING == 'quit' ]; do

        echo $STRING | tr 'a-z' 'A-Z'

read -p "Input something:" STRING

done

#!/bin/bash

#

who | greo "hadoop" &> /dev/null

RETVAL=$?

until [ $RETVAL -eq 0 ]; do

        echo "hadoop hasn't come"

        sleep 5

        who | greo "hadoop" &> /dev/null

        RETVAL=$?

done

echo "hadoop logged in."

对比上下2个

#!/bin/bash

#

until who | greo "hadoop" &> /dev/null; do

echo "hadoop hasn't come"

        sleep 5

done

echo "hadoop logged in."

for 变量 in 列表; do

循环体

done

for (( expr1 ; expr2 ; expr3 ));do

循环体

done

#!/bin/bash

#

declare -i SUM=0

for I in {1..100}; do

  let SUM+=$I

done

echo $SUM

declare -i SUM2=0

for ((J=1;J<=100;J++)); do

  let SUM2+=$J

done

echo $SUM2

写一个脚本：

1、通过ping命令测试192.168.0.151到192.168.0.254之间所有主机是否在线

如果在线，就显示“ip is up”,其中的IP要换为真正的IP地址，且以绿色显示

如果不在线，就显示“ip is down”，其中的IP要换为真正的IP地址，且以红色显示

要求：分别使用while,until和for（两种形式）循环实现

ping 

-c 

-w

awk “pattern{action}” file

需要复习 包括11_01前半部分