Complete AMD64 Handbook/Starting from minimal environment

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The prompt you are now looking at is all-powerful, but a bit daunting at first. If you know how the Linux command line works, this chapter will give you no further surprises and you can easily jump to the next chapter, Preparing the Network.

Basic navigation

Working command-line

At the prompt you can enter commands to the Gentoo Linux environment. Basic commands are just single words, like ls or ps. Most commands however often require additional words to be added, like cd /var or man ls. These added characters are called arguments.

More often, these arguments represent certain options to the command. For instance, the ls command (used to list the content of a directory) can take several options, like -l (for a lengthy description of each found file), -a (to include hidden files), etc.

In the next code listing you'll see this terminology explained. The command shown will list the content of the /var/tmp directory (a temporary location) showing additional information about each file found, including hidden files.

root # ls -la /var/tmp
<-+--><+> <+> <---+-->
  |    |   |      `- Argument, in this case the target directory to list
  |    |   `- Argument, also two options: lengthy description + hidden files
  |    `- Command (list in this case)
  `- Prompt

After having constructed a command, you can execute it by pressing the Return key. Your shell (the command-line environment you are currently "in" which interprets commands and helps you navigate through the Linux environment) will then execute the command and show you the results.

The next section will give you a crash course in certain Linux commands that will help you explore your current minimal Gentoo environment. We won't go in much detail - there are plenty of guides and books available online that will inform you about the basic Linux tools.

Navigating up and down

We have already covered how a Linux file system looks like (the hierarchical structure, remember?). To help you out we'll give you a quick overview on the most common tools you might need to navigate on your Gentoo Linux system:

Command Description
ls List the content of a given directory, or the current directory if no directory is given.
user $ls /mnt/cdrom
pwd Show the current working directory; this is the full pathname of the directory you are currently in.
user $pwd
cd Change the current working directory to a different location. If no directory is given, go to the user's home directory.
user $cd /mnt/gentoo
less Show the content of a given file on the screen. You can navigate with the and arrow keys through the file and quit the application by pressing q.
user $less install.txt
rm Remove a file from the system (if you have the required privileges). To remove a directory with all files in it, use the -r option. Be careful with this command though, it won't warn you when you are about to destroy all your data.
user $rm portage.tar

Concurrent terminals

Gentoo's installation CDs allow you to use a couple of terminals simultaneously. That means you can work in one, browse the internet in another and chat on a third. To switch between terminals, type Alt + F# (with F# one of the function keys). You will notice that your current session is at F1.

You can also work in a terminal and then put your working session in the background using a powerful tool called screen. With screen you can even let other people work on your terminal while you are watching every step they perform.

Starting a screen session:

user $screen -S mySession

To detach a screen session, type Ctrl + A followed by a d.

Reattach to a screen session:

user $screen -x mySession

To quit a screen session, just type 'exit':

user $exit

Networking utilities

Gentoo offers a few utilities on the installation CDs which you can use to surf on the Internet, download files, chat on the IRC network, etc. We will cover a few of them in this section, but you can't use them until you have configured your network (and Internet connection) which is described in the next chapter.

Surfing on the Internet

Because no documentation can be perfect and no two environments are alike, you will often search for additional information and help on the Internet. Websites such as the main Gentoo documentation repository or powerful search engines like Google are a welcome resource during your installation quest.

To browse through these sites you need a browser. Because the Gentoo installation CDs don't contain a graphical environment you need to use either a different system, a different installation medium or a non-graphical browser. The Gentoo installation CDs offer at least one of the following console browsers:

  • lynx, a general purpose web site browser which operates key-driven (for instance D for downloading, G to go to a different site, ...).
  • links2, a featureful browser with support for frames, limited JavaScript, svgalib/framebuffer, background downloading, ... which operates both menu-driven (press Esc to open the menu) as key-driven.

Both browsers support proxy servers, although the first one uses the standard way (setting an HTTP_PROXY environment variable) while the second one requires you to enter the proxy server in the browser.

For lynx - ignore the export command if no proxy is needed:

user $export HTTP_PROXY="http://myproxy.server.tld:8080"

For links2 - ignore the -http-proxy option if no proxy is needed:

Chatting on an IRC network

When you can't find useful information on the Internet, you can always ask your question on the #gentoo-install or #gentoo IRC channels on FreeNode. Gentoo delivers a terminal-based, yet extremely powerful chat client called irssi.

Its use is quite simple. First, connect to the IRC network. Then, join the channel(s) you want to participate in. You can use Alt + F# to switch between channels (or type in /window # if the key combination fails). To exit the application, type /quit.

user $irssi -c irc.freenode.net YourNickName
## (Wait until the connection is made)
[irssi #] /join #gentoo

Remote shell access

The Gentoo installation CD contains an SSH daemon, which is a tool to allow others to securely connect to your system so they can help you install Gentoo. This service isn't started by default, but if you want to use it you should:

  • get the Internet connection up and running
  • create a user account
  • give the root account a password
  • start the SSH daemon

If you trust the other person, you can give him your root password, but we advise you to only give limited access to the other person - they should help you identify errors and tell you how to resolve them, not fix the errors themselves. Otherwise you won't learn :)

First get the Internet connection up and running, then add the myuser user and give it a password:

root #useradd -m -G users myuser
root #passwd myuser

Now give the root user a (different) password:

root #passwd

At this point you can start the sshd service:

root #rc-service sshd start

The passwords you set here are limited to the Gentoo installation CD environment and only until you reboot. They are not used for your final Gentoo installation!