1、数字循环

[root@zabbix ~]# for i in {1..10};do echo $(expr $i \* 3);done;

3

6

9

12

15

18

21

24

27

30

[root@zabbix ~]# for i in `seq 1 10`;do echo $(expr $i \* 3);done;

3

6

9

12

15

18

21

24

27

30

[root@zabbix ~]# for((i=1;i<=10;i++));do echo $(expr $i \* 3);done

3

6

9

12

15

18

21

24

27

30

[root@zabbix ~]# awk 'BEGIN{for(i=1; i<=10; i++) print i*3}' 

 

2、字符型循环

[root@zabbix ~]# for i in f1 f2 f3;do echo $i is appoint ;done

f1 is appoint

f2 is appoint

f3 is appoint

[root@zabbix ~]# list="rootfs usr data data2"

[root@zabbix ~]# for i in $list;do echo $i is appoint;done

rootfs is appoint

usr is appoint

data is appoint

data2 is appoint

3、路径查找

[root@zabbix ~]# for file in /media/*;do echo $file \!;done

/media/CentOS_BuildTag !

/media/EFI !

/media/EULA !

/media/GPL !

/media/images !

/media/isolinux !

/media/LiveOS !

/media/Packages !

/media/repodata !

/media/RPM-GPG-KEY-CentOS-7 !

/media/RPM-GPG-KEY-CentOS-Testing-7 !

/media/TRANS.TBL !

[root@zabbix ~]# for file in $(ls *.sh); do echo $file;done

a.sh

key.sh

li.sh

long.sh

test.sh

 

4、for循环嵌套if...then....else语句

[root@zabbix ~]# cat li.sh

#!/bin/bash

for i in {1..100}

do

if (( $i \* 5 == 100 ));then

echo $i

fi

done

###打印1到100内的数字，如果这个数字乘以5等于100，那么打印该数字

[root@zabbix ~]# cat li.sh

#!/bin/bash

for i in {1..10}

do

if (( $i/5 == 0 ));then

echo $i

fi

done

###打印1到10内的数字，如果这个数字除以5的余数等与0，那么打印出所有数字