* Author : Samson
* Date : 11/06/2013
* Test platform:
* 3.6.10-4.fc18.i686.PAE
* GNU bash, version 4.2.39
* *******************************************************************/
for 实现：
#!/bin/bash
set i=0
set j=0
for((i=0;i<10;))
do
let "j=j+1"
echo "-------------j is $j -------------------"
done
while实现：
#!/bin/bash
set j=2
while true
do
let "j=j+1"
echo "----------j is $j--------------"
done