for循环无参数取值列表的使用

 1 [root@localhost array]# cat for.sh 
 2 #!/bin/bash
 3 for i 
 4 do
 5     #echo abc
 6     let sum+=$i
 7 done
 8     echo $sum
 9 [root@localhost array]# sh for.sh  1 2 3 4 5
10 15
11 [root@localhost array]# 

等价与

 1 [root@localhost array]# cat for.sh
 2 #!/bin/bash
 3 for i in $*
 4 do
 5     #echo abc
 6     let sum+=$i
 7 done
 8     echo $sum
 9 [root@localhost array]# sh for.sh  1 2 3 4 5
10 15
11 [root@localhost array]#