Linux中whatis命令的解释

Question

[疑问] 关于whatis显示的问题
比如：
[root@server1 ~]# whatis ls
ls

(1) - list directory contents
ls

(1p) - list directory contents
[root@server1 ~]# whatis cat
cat

(1) - concatenate files and print on the standard output
cat

(1p) - concatenate and print files
其中（）里的l和lp分别代表什么意思啊？问什么后面有的一样，有的不一样？

Answer 1

　　whatis命令在用catman -w命令创建的数据库中查找command参数指定的命令、系统调用、库函数或特殊文件名。whatis命令显示手册部分的页眉行。然后可以发出man命令以获取附加的信息。whatis命令等同于使用man -f命令。

　　实例

Answer 2

里面的1和1p是section
常见的包括

Sections of the Manual Pages
The manual Sections are traditionally defined as follows:
1 Commands (Programs)
Those commands that can be executed by the user from within a shell.
2 System calls
Those functions which must be performed by the kernel.
3 Library calls
Most of the libc functions.
4 Special files (devices)
Files found in /dev.
5 File formats and conventions
The format for /etc/passwd and other human-readable files.
6 Games
7 Conventions and miscellaneous
Overviews of various topics, conventions and protocols, character set standards, and miscellaneous other things.
8 System management commands
Commands like mount(8), many of which only root can execute.

此外：
man-pages currently includes pages from the POSIX.1 standard in Section 0p (Header Files), 1p (Commands), and 3p (Functions).本回答被网友采纳