Server Command Options
When you start the mysqld server, you can specify program options
using any of the methods described in Section 4.2.3, “Specifying Program
Options”. The most comm...
man grep的时候有一个-P，文档上的英文：
-P, --perl-regexp
Interpret PATTERN as a Perl regular expression. This is highly experimental and grep -P may warn of nimplemented feat...
