I'm using the built-in grep command to display the Table Of Content of my own bash cheatsheet.
Titles looks like this: [3.1] - REMOTE LOGIN TO A HOST OR INSTANCE
这是命令：
grep -E '\[[0-9][0-9]?\.?[0-9]?[0-9]?\] - [A-Z]+' $FILE | less
The pattern is supposed to match all my titles, as you can see here
但是，由于我忽略的原因，模式不匹配：
[2.10]
[2.11]
[2.12]
但匹配：
[2.1]
...
[2.9]
[2.13]
[2.14]
任何人 ？
