Two small problems, not even a problem, but still remember it, and I will definitely forget it in the future. . .
1. When apt-get installs software, there is a source that keeps reporting 403; so I plan to delete this source from /etc/apt/sources.list, but it turns out that there is no such source, and finally /etc/apt/sources.list .d/ found below.
2. I used to think that PHP installed by apt-get cannot install extensions by compiling. . . In fact, it is possible, mainly to find the phpize executable file;