To get information about a command (here ps), type:
# man ps
Sometimes several man pages exist for a command, to know them, type:
# whatis ps ps (1) - report a snapshot of the current processes ps (1p) - report process status
If you are not sure about the command name and want to search for a string (here ps), type:
# apropos ps capsh (1) - capability shell wrapper ... getpt (3) - open the pseudo-terminal master (PTM)
To update the whatis database, type:
Alternatively, some commands (here ipc) have additional documentation that you can get by typing:
# info ipc
To get the list of these commands, type:
# ls /usr/share/info
Finally, most packages come with their own documentation in the /usr/share/doc directory.
In RHEL7 and CentOs7 “makewhatis” is replaced by “mandb”.Can be useful for the RHCSA exam.
You are perfectly right. I have created a new page dedicated to RHEL 7 on this topic.
Thanks for this useful comment.