shell 之for循环几种写法

第一类：数字性循环
-----------------------------
for1-1.sh

#!/bin/bash
 
for((i=1;i<=10;i++));
do 
echo $(expr $i \* 3 + 1);
done

 

-----------------------------
for1-2.sh

 

#!/bin/bash
 
for i in $(seq 1 10)
do 
echo $(expr $i \* 3 + 1);
done

 

-----------------------------
for1-3.sh

#!/bin/bash
 
for i in {1..10}
do
echo $(expr $i \* 3 + 1);
done

 

-----------------------------

 

for1-4.sh 

#!/bin/bash
 
awk 'BEGIN{for(i=1; i<=10; i++) print i}'

 

第二类：字符性循环
-----------------------------
for2-1.sh

 

#!/bin/bash
 
for i in `ls`;
do 
echo $i is file name\! ;
done

 

 

-----------------------------
for2-2.sh

 

#!/bin/bash
 
for i in $* ;
do
echo $i is input chart\! ;
done

 

-----------------------------
for2-3.sh

#!/bin/bash
 
for i in f1 f2 f3 ;
do
echo $i is appoint ;
done

 

-----------------------------
for2-4.sh

#!/bin/bash
 
list="rootfs usr data data2"
for i in $list;
do
echo $i is appoint ;
done

 

第三类：路径查找
-----------------------------
for3-1.sh

#!/bin/bash
 
for file in /proc/*;
do
echo $file is file path \! ;
done

 

-----------------------------

 

for3-2.sh

#!/bin/bash
 
for file in $(ls *.sh)
do
echo $file is file path \! ;
done

 

 

参见博客 http://blog.csdn.net/babyfish13/article/details/52981110 。