shell编程学习之tr

tr

tr可以对标准输入的字符进行替换、删除、压缩

 

 

1、替换

-bash-3.2# cat 1.txt
a b c
-bash-3.2# cat 1.txt |tr 'a-c' 'A-C'
A B C

 

 

2、删除某个字符

-bash-3.2# cat 1.txt |tr -d 'c'
a b

 

 

3、过虑字符

-bash-3.2# cat 2.txt
hello2 shell3
-bash-3.2# cat 2.txt |tr -d -c 'a-z \n'
hello shell

 

 

4、压缩

-bash-3.2# echo "linux      and       windows"|tr -s  '      '#三个空格
linux and windows

 

 

5、简单计算

-bash-3.2# cat 1.txt
1 2 3 4 5 6
-bash-3.2# cat 1.txt |echo $[ $( tr ' ' '+' ) ]
21