原文：http://bash.cyberciti.biz/academic/reverse-the-number-script/
例子1
读取输入数字：
Enter number :582
输出结果：
582 in a reverse order 285
以下是该shell脚本的源代码：
#!/bin/bash
# Shell program to read a number and reverse the number
# for example 123 should output as 321
# -----------------------------------------------
# Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
echo -n "Enter number : "
read n
# store single digit
sd=0
# store number in reverse order
rev=""
# store original number
on=$n
# use while loop to caclulate the sum of all digits
while [ $n -gt 0 ]
do
sd=$(( $n % 10 )) # get Remainder
n=$(( $n / 10 )) # get next digit
# store previoues number and current digit in rev
rev=$( echo ${rev}${sd} )
done
echo "$on in a reverse order $rev" |