Linux From Scratch - Version 12.0

Chapter 4. Final Preparations

4.3. Adding the LFS User

When logged in as user root, making a single mistake can damage or destroy a system. Therefore, the packages in the next two chapters are built as an unprivileged user. You could use your own user name, but to make it easier to set up a clean working environment, we will create a new user called lfs as a member of a new group (also named lfs) and run commands as lfs during the installation process. As root, issue the following commands to add the new user: 

groupadd lfs
useradd -s /bin/bash -g lfs -m -k /dev/null lfs

This is what the command line options mean:

-s /bin/bash

This makes bash the default shell for user lfs.

-g lfs

This option adds user lfs to group lfs.

-m

This creates a home directory for lfs.

-k /dev/null

This parameter prevents possible copying of files from a skeleton directory (the default is /etc/skel) by changing the input location to the special null device.

lfs

This is the name of the new user.

If you want to log in as lfs or switch to lfs from a non-root user (as opposed to switching to user lfs when logged in as root, which does not require the lfs user to have a password), you need to set a password for lfs. Issue the following command as the root user to set the password: 

passwd lfs

Grant lfs full access to all the directories under $LFS by making lfs the owner: 

chown -v lfs $LFS/{usr{,/*},lib,var,etc,bin,sbin,tools}
case $(uname -m) in
  x86_64) chown -v lfs $LFS/lib64 ;;
esac
[Note]

Note

In some host systems, the following su command does not complete properly and suspends the login for the lfs user to the background. If the prompt "lfs:~$" does not appear immediately, entering the fg command will fix the issue.

Next, start a shell running as user lfs. This can be done by logging in as lfs on a virtual console, or with the following substitute/switch user command: 

su - lfs

The “-” instructs su to start a login shell as opposed to a non-login shell. The difference between these two types of shells is described in detail in bash(1) and info bash.