Lab 4: How to Get Help in Linux

Objective Focus

Understand and use essential tools: Locate, read, and use system documentation including man, info, and files in /usr/share/doc

Getting help in a Red Hat Linux environment, or any Linux OS, starts with your end goal.

For example, I need to know the last created directory in user learners home directory. Let us create a new directory

 $ mkdir newdir

First, we learned about $ ls in Lab 2, that will help us list out the files in the directory.

   [learner@server1 ~]$ ls
	Desktop  Documents  Downloads  Music  Pictures  Public  Templates  Videos

$ ls alone does not meet our end goal.
From here we have several options
Help option, usually an option like
```
 $ command  -h --help 
```
- Not all commands have the -h, –help option but it is always worth checking
- Sometimes, just typing in a error with a command will bring this up
Next are Man Pages, short for Manual Pages.
- Using man pages is going to be essential to passing the EX200.
- These manual pages are going to be avaliable to you during the exam.
To get the manual page on $ ls, we use the systax $ man “command”

 [learner@server1 ~]$ man ls

This brings up the manual page for $ ls, the table below shows us how to navigate a man page.

Buttons	What they do
Up/Down Arrow	Move view of page up and down
Spacebar	Move down one page
g/G	Move to top man page/ Move to bottom of man page
q	exit the man page
/pattern	Searches forward in man page
?pattern	Searches forward in man page
n/N	Find next/previous pattern match
h	help with summary of commands

Lets look at some available options, below are the ones that stand out for our goal

 -l     use a long listing format

 -t     sort by time, newest first; see --time

How to look for a command searching man pages

$ man -k "keyword": To search man pages for keywords

[learner@server1 ~]$ man -k list
list: nothing appropriate.

If the above happens use the following command to index the man pages on the system.

$ mandb

The /usr/share/doc directory

This directory contains an extensive list of documents related to software and programs on the system. Whenever the man pages and comman line tools, be sure to search here for more supporting information

 $ ls -l /usr/share/doc

Info Pages

Info pages are a great resource and provide a lot of details
Getting to info pages are the same as getting to man pages

 $ info ls

Press ‘h’ to get help on info pages and how to navigate

That is it for Lab 4, man pages and help options should suffice for the EX200 and we will continue use them through out the rest of the course.

Trying to remember every command and avaliable option is impossible, so learning how to be resourceful is the key to completing every task.

I am going to include the docs availiable on Red Hats website here.

Read them for a cross reference to the man pages and help options.

The most important take away is getting comfortable reaching for man pages and internal system tools before googling and reaching out to the internet. :wq