How To: Update and Refresh Cache with mandb Command

[Waldirio]

Hello,

Did you know that there's a database/index file that's used whenever you run the "man -k something" or "apropos something" command? And sometimes, when this file isn't updated and/or is missing, the result is empty, which can sometimes be a tricky one for the sysadmins.

In this video, you'll learn how to update and/or recreate this index.

https://www.youtube.com/watch?v=EpZldFVdZ-0

Enjoy it!
Wally

[Chetan_Tiwary_]

@Waldirio Nice addition! Are man -k and apropos truly the same?

[PetrCihlar]

According to the video and what I have heard, the man -k and apropos are the same. Just apropos is newer.

I think mandb updates the index file and recreates it if it does not exist. It may be better to use mandb -c directly, which does not update the existing index file (it may be damaged), but recreates it immediately.

[Waldirio · Accepted solution]

Hey @Chetan_Tiwary_ 

Just a snippet from "man man"

---
-k, --apropos
Equivalent to apropos. Search the short manual page descriptions for keywords and display
any matches. See apropos(1) for details.
---

So, yea, we can say that they are pretty much equivalent

Best

Wally

[Chetan_Tiwary_]

oh no, oh yes @Waldirio ! Straight drop from the man page ! Thanks for clarifying!