Display one-line manual page descriptions
The whatis command searches the manual page names and descriptions for the given command and prints the result to the terminal.
The command searches a database created by mandb (or catman -w on older systems) for the command name, system call, library function, or special filename. It displays the header line of the manual page, which typically contains a one-line description. This is equivalent to running man -f.
whatis [command]
[root@localhost ~]# whatis ls
ls (1) - list directory contents
ls (1p) - list directory contents
[root@localhost ~]# whatis cp
cp (1) - copy files and directories
cp (1p) - copy files
[root@localhost ~]# whatis chown
chown (1) - change file owner and group
chown (1p) - change the file ownership
chown (2) - change ownership of a file
chown (3p) - change owner and group of a file
[root@localhost ~]# whatis man
man (1) - format and display the on-line manual pages
man (1p) - display system documentation
man (7) - macros to format man pages
man (rpm) - A set of documentation tools: man, apropos and whatis.
man-pages (rpm) - Man (manual) pages from the Linux Documentation Project.
man.config [man] (5) - configuration data for man