man page中命令后的数字释义

# manpage中命令后的数字释义
[linux manpage](https://www.kernel.org/doc/man-pages/#:~:text=The%20%EE%80%80Linux%EE%80%81%20%EE%80%80man-pages%20project%EE%80%81.%20The%20%EE%80%80Linux%EE%80%81%20%EE%80%80man-pages%20project%EE%80%81,C%20libraries%20available%20for%20%EE%80%80Linux%EE%80%81%20is%20also%20included. "linux manpage")
Linux下最通用的领域及其名称及说明如下：

| 领域 | 名称 | 说明 |
|-----| -----------| ----------------|
| 1 | 用户命令 | 可由任何人启动的。|
| 2 | 系统调用 | 即由内核提供的函数。 |
| 3 | 例程 | 即库函数。|
| 4 | 设备 | 即/dev目录下的特殊文件。 |
| 5 | 文件格式描述 | 例如/etc/passwd。 |
| 6 | 游戏 | 有什么好玩的游戏推荐吗？ |
| 7 | 杂项 | 例如宏命令包、惯例等。|
| 8 | 系统管理员工具 | 只能由root启动。|
| 9 | 其他（Linux特定的）| 用来存放内核例行程序的文档。 |
| n | 新文档 | 可能要移到更适合的领域。|
| o | 老文档 | 可能会在一段期限内保留。|
| l | 本地文档 | 与本特定系统有关的。 |

1: User commands; man-pages includes a small number of Section 1 pages that document programs supplied by the GNU C library.
2: System calls documents the system calls provided by the Linux kernel.
3: Library functions documents the functions provided by the standard C library.
4: Devices documents details of various devices, most of which reside in /dev.
5: Files describes various file formats and filesystems, and includes proc(5), which documents the /proc file system.
7: Overviews, conventions, and miscellaneous.
8: Superuser and system administration commands; man-pages includes a small number of Section 8 pages that document programs supplied by the GNU C library.