Shell中for循环的几个常用写法

第一类：数字性循环
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for1-1.sh

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

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for1-2.sh

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

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for1-3.sh

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

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for1-4.sh

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

第二类：字符性循环
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for2-1.sh

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

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for2-2.sh

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

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for2-3.sh

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

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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
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for3-1.sh

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

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for3-2.sh

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