Newbie School: System Service owner, group, and permission Overview

System Service

Each running level has different functions, mainly because the running system services are different. One way to view a running level of System services is to switch to the running level, Run "setup" on the terminal, and find "System services. You can also directly execute "ntsysv" on the terminal.

In general, "network", "smb" (Window network neighbor), and "smbupdate" are required in runtime Level 3 and 5.

Owner, group, and permission

UNIX systems are both public and private systems. They are clear and unambiguous about which resources can be accessed. Take a closer look at the file attributes of Linux. It divides all users on the machine into three categories: file owners, users in the same group as file owners, and other users, each type has three tags: "readable", "writable", and "executable. For a directory, "executable" means access.

In Linux, the executable file is not marked with a suffix. As long as the file attribute is executable to the user, Linux considers it executable, whether it is a binary code or a text file. As for the execution result, you can view the file yourself.