cat -n查看内容为前面添加行号，nl查看内容为非空行前面添加行号
[root@fwq test]# cat -n regular_express.txt
1 "Open Source" is a good mechanism to develop programs.
2 apple is my favorite food.
3 Football game is not use feet only.
4 this dress doesn't fit me.
5 However, this dress is about $ 3183 dollars.
6 GNU is free air not free beer.
7 Her hair is very beauty.
8 I can't finish the test.
9 Oh! The soup taste good.
10 motorcycle is cheap than car.
11 This window is clear.
12 the symbol '*' is represented as start.
13 Oh! My god!
14 The gd software is a library for drafting programs.
15 You are the best is mean you are the no. 1.
16 The world <Happy> is the same with "glad".
17 I like dog.
18 google is the best tools for search keyword.
19 goooooogle yes!
20 go! go! Let's go.
21 # I am VBird
22
[root@fwq test]# nl regular_express.txt
1 "Open Source" is a good mechanism to develop programs.
2 apple is my favorite food.
3 Football game is not use feet only.
4 this dress doesn't fit me.
5 However, this dress is about $ 3183 dollars.
6 GNU is free air not free beer.
7 Her hair is very beauty.
8 I can't finish the test.
9 Oh! The soup taste good.
10 motorcycle is cheap than car.
11 This window is clear.
12 the symbol '*' is represented as start.
13 Oh! My god!
14 The gd software is a library for drafting programs.
15 You are the best is mean you are the no. 1.
16 The world <Happy> is the same with "glad".
17 I like dog.
18 google is the best tools for search keyword.
19 goooooogle yes!
20 go! go! Let's go.
21 # I am VBird