1.利用while循環計算1到100的和：

示例代碼1：

#!/bin/bashi=1sum=0while [ $i -le 100 ]do let sum=sum+$i let i++doneecho $sum

示例代碼2：利用while循環計算1到100之間所有奇數之和

#!/bin/bashi=1sum=0while [ $i -le 100 ]do let sum=sum+$i let i+=2doneecho $sum

示例代碼3：利用while循環計算1到100之間所有偶數之和

#!/bin/bashi=2sum=0while [ $i -le 100 ]do let sum=sum+$i let i+=2doneecho $sum

2.利用while循環打印**

示例代碼：利用while循環打印一個5x5的*

#!/bin/bashi=1j=1while [ $i -le 5 ]do while [ $j -le 5 ] do   echo -n "* "   let j++ done echo let i++ let j=1done

3.使用read結合while循環讀取文本文件：

示例代碼1：

#!/bin/bashfile=$1         #將位置參數1的文件名復制給fileif [ $# -lt 1 ];then   #判斷用戶是否輸入了位置參數 echo "Usage:$0 filepath" exitfiwhile read -r line  #從file文件中讀取文件內容賦值給line（使用參數r會屏蔽文本中的特殊符號，只做輸出不做轉譯）do echo $line    #輸出文件內容done  < $file

示例2：按列讀取文件內容

#!/bin/bashfile=$1if [[ $# -lt 1 ]]then echo "Usage: $0 please enter you filepath" exitfiwhile read -r f1 f2 f3  #將文件內容分為三列do echo "file 1:$f1 ===> file 2:$f2 ===> file 3:$f3"  #按列輸出文件內容done < "$file"

4.while循環中的死循環：

示例：利用死循環，讓用戶做選擇，根據客戶的選擇打印相應結果

#!/bin/bash#打印菜單while :do echo "********************" echo "    menu    " echo "1.tima and date" echo "2.system info" echo "3.uesrs are doing" echo "4.exit" echo "********************" read -p "enter you choice [1-4]:" choice#根據客戶的選擇做相應的操作 case $choice in  1)  echo "today is `date +%Y-%m-%d`"  echo "time is `date +%H:%M:%S`"  read -p "press [enter] key to continue..." Key  #暫停循環，提示客戶按enter鍵繼續  ;;  2)  uname -r  read -p "press [enter] key to continue..." Key  ;;  3)  w  read -p "press [enter] key to continue..." Key  ;;  4)  echo "Bye!"  exit 0  ;;  *)  echo "error"  read -p "press [enter] key to continue..." Key  ;; esacdone