linux的for循环怎么写,Linux命令：for循环写法总结

for循环写法总结

关于shell中的for循环用法很多，感觉很全面，所以就转过来研究研究，嘿嘿...

1、 for((i=1;i<=10;i++))

[[email protected] ~]# for ((i=1;i<3;i++ )); do echo $(($i*4)); done

4

8

2、在shell中常用的是for i in $(seq 10)

[[email protected] ~]# for i in $(seq 2); do echo $(($i*4)); done

4

8

3、for i in {1..10}

[[email protected] ~]# for i in {1..2}; do echo $(($i*4)); done

4

8

4、for i in stringchar {1..10}

[[email protected] ~]# for i in user{1..2}; do echo $i; done

user1

user2

5、for i in `ls`

[[email protected] ~]# for i in `ls`; do echo $i; done

6、for i inf1 f2 f3 ;do

[[email protected] ~]# for i in 2 8 20; do echo $(($i*4)); done

8

32

80

7、for i in *.txt

[[email protected] ~]# for i in *.txt ;do echo $i ; done    #相当于ls *.txt

second.txt

userinfo.txt

8、for i in $(ls *.txt)#利用` `或$( )的将多行合为一行，实际是合为一个字符串数组

[[email protected] ~]# for i in $(ls *.txt) ;  do echo $i ;   done

second.txt

userinfo.txt

9、for i in $* ; do      #  $*表示脚本输入的所有参数

10、for i in ${arr[@]}

11、for File in /proc/sys/net/ipv4/conf/*/accept_redirects; do

13、awk ‘BEGIN{for(i=1; i<=10; i++) print i}‘  #AWK中的for循环写法和C语言一样的

12、用for in语句自动对字符串按空格遍历的特性，对多个目录遍历

LIST="rootfs usr data data2"

for d in $LIST; do

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