shell变量子串应用技术

[[email protected] zhouyu]# a="i am zhouyu"

[[email protected] zhouyu]# echo ${#a}

11

[[email protected] zhouyu]# echo $a | wc -m

12

[[email protected] zhouyu]# echo ${a:2}

am zhouyu

[[email protected] zhouyu]# echo ${a:2:3}

am

[[email protected] zhouyu]# echo $a | cut -b 3-4

am

[[email protected] zhouyu]# echo ${a#i am}

zhouyu

[[email protected] zhouyu]# echo ${a##i am}

zhouyu

[[email protected] zhouyu]# echo ${a%zhouyu}

i am

[[email protected] zhouyu]# echo ${a%%zhouyu}

i am

[[email protected] zhouyu]# echo ${a/i am/you are}

you are zhouyu

[[email protected] zhouyu]#

下面我们写一个脚本让1_zhouyu.txt 2_zhouyu.txt 3_zhouyu.txt这三个文件的名字改名为1.txt 2.txt 3.txt文件，怎么更改呢。可以参考我写的下面文件

有什么更好的方法还请大牛给点意见

vim /root/zhouyu/1.sh内容为

cd /root/zhouyu

for i in `ls *.zhouyu.txt`;

do

mv $i ${i/_zhouyu.txt/.txt}

done

这样就去执行就成功了

下面说一下专门用于更改文件名的命令rename，其用法如下：

rename 想改的部分 改成什么 改变的源文件,下面是例子

[[email protected] zhouyu]# ls

1.txt  2.txt  3.txt  zhouyu.sh

[[email protected] zhouyu]# rename .txt .TXT /root/zhouyu/*

[[email protected] zhouyu]# ls

1.TXT  2.TXT  3.TXT  zhouyu.sh

[[email protected] zhouyu]#