/ Usr / share / man directory
When we use the man command(command represents instructions) can obtain the usage instructions, detailed descriptions.
Then these details come from it, it can not come out of thin air! In fact, by reading the documentation to achieve this effect, these documents will be stored in / usr / share / man directory
empathy as well as / usr / share / info directory, the directory is stored using the infouse command description file
/usr/share/doc
When you install the software, usually installed some of the documentation to / usr / share under the / doc directory, such as installing mysql, then in / usr / share / doc directory will appear mysql-community-common-5.7.21 directory to store some
mysql description, usage, etc.
/ Etc / passwd file
All user information is stored in a location
/ Etc / shadow file
All user passwords stored position
/ Etc / group file
All group information storage location
Reproduced in: https: //www.cnblogs.com/liu-shijun/p/11065808.html