DESCRIPTION man is the system's manual pager. Each page argument given to man is normally the name of a program, utility or function. The manual page associated with each of these arguments is then found and displayed. A section, if provided, will direct man to look only in that section of the manual. The default action is to search in all of the available sections, following a pre-defined order and to show only the first page found, even if page exists in several sections. The table below shows the section numbers of the manual followed by the types of pages they contain. 1 Executable programs or shell commands # 可执行程序，或 shell 命令 2 System calls (functions provided by the kernel) # 系统调用(内核提供的函数) 3 Library calls (functions within program libraries) # 库调用(程序库中的函数) 4 Special files (usually found in /dev) # 特殊文件(通常在/dev中找到) 5 File formats and conventions eg /etc/passwd # 文件格式和约定(如/etc/passwd) 6 Games # 游戏 7 Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7) # 其他(包括宏包和约定)，例如man(7)， groff(7) 8 System administration commands (usually only for root) # 系统管理命令(通常仅适用于 root 用户) 9 Kernel routines [Non standard] # 内核例程[非标准] A manual page consists of several sections. Conventional section names include NAME, SYNOPSIS, CONFIGURATION, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT, FILES, VERSIONS, CONFORMING TO, NOTES, BUGS, EXAMPLE, AUTHORS, and SEE ALSO. The following conventions apply to the SYNOPSIS section and can be used as a guide in other sections.