new features: 1: Add a dongle detection method. 2: Increase the detection of a series of dongle models. Currently there are more than 50 types of dongles that can be detected. The specific types that can be detected are as follows: Flying faithful,
Linux最强三剑客 sed grep awk 写的很不错，值得收藏。20192/19
不看绝对后悔的Lnux二剑客之aw实战精讲-飞得更高-51CTO博客
mail x mail var spool mail sbin nologin
uucp x uucp var spool uucp sbin nologin
思路
让所有单词排成一列,这样每个单词都是单独的一行
1)设置RS值为空格
2)将文件里面的所有空格替换为回奂行符n
3)grep所有连续的字母,grep-0参数让他们排成一
