Sed

 

1. 全词替换
   

   echo bar embarassment | sed 's/\bbar\b/BAR/g'
   echo bar embarassment | sed 's/\<bar\>/BAR/g'

    

2. -i.bak 替换的同时备份原文件
   

    

    

   1 Unix unix unix 23
   2 linux Linux 34
   3 linuxunix UnixLinux
   linux /bin/bash CentOS Linux OS
   Linux is free and opensource operating system

    

3. sed 's/search_string/replacement_string/2' sample
   替换第二个

   
   
   简单用法示例:https://linux.cn/article-11367-1.html

    

4.  行首或行尾添加内容

   sed -i.bak '/^[[:lower:]]/ s#^#HEAD&#g' sample
   sed -i.bak '/^[[:digit:]]/ s#^#&TAIL#g' sample
   sed -i.bak '/./ s#^#HEAD&#;s#$#&TAIL#' sample

    

5. 删除'\r'
   

   sed -i 's/\r//g' sample

    

6.  分组提取

    echo "background-image: url(/media/images/index/im2.jpg);"|sed -nr 's|^.*url\((.+)\).*$|\1|p'

   

    

7. IGNORECASE