As the saying goes: "It is better to teach a man to fish than to give him a fish", here we will discuss how to use an important tool in Linux - help documentation.
There are several commands related to the help documentation, but the most commonly used command is the man command, which is the abbreviation of manual. It is used to view various reference manuals that come with the system (note that it is not just commands). For example, we are now going to look at the help documentation for the who command. The simplest usage is as follows:
[stu@localhost ~]$ man who
Of course, the document format of different commands (programs) may be slightly different, and the
items are:
COMMANDS When this command (program) is running, the internal commands can be executed in this command (program);
FILES Some files used by or related to the command (program) or data;
EXAMPLES Some reference examples of the execution of this command (program).
在 man 界面中，可以使用如下快捷键来进行操作：
上/下箭头 向上/下滚动一行
[Space] 向下翻一页
[Page Down] 向下翻一页
[Page Up] 向上翻一页
[Home] 回退到第一页
[End] 前进到最后一页
/string 向下搜寻 string 这个字符串
?string 向上搜寻 string 这个字符串
n, N 利用 / 或 ? 来搜寻字符串时，可以用 n 来跳转至下一个匹配 处 ，可以利用 N 来跳转至上一个匹配处 。
[q] 退出The man command can be followed by a number to indicate the user manual to consult. If no number is added, the man command will look for the relevant content from the manual with a smaller number by default:
1. Instructions or executable files that can be operated in the shell
2. Functions and tools that can be used by the system core
3. Some commonly used functions ( function) and library (library), most of which are C libraries (libc)
4. Description of device files, usually files under /dev
5. Configuration files or the format of some files
6. Games
7. Conventions and protocols etc., such as the description of the Linux file system system, network protocols, ASCII codes, etc.
8. Administration commands available to system administrators 9. Files related to the system core