In order for user root to be able to login and for the name “root” to be recognized, there must be relevant entries in the /etc/passwd and /etc/group files.
Create the ${CLFS}/etc/passwd file by running the following command:
cat > ${CLFS}/etc/passwd << "EOF"
root::0:0:root:/root:/bin/bash
EOF
The actual password for root (the “::” used here is just a placeholder and allow you to login with no password) will be set later.
Additional users you may want to add:
Can be useful for compatibility with legacy applications.
It is often recommended to use an unprivileged User ID/Group ID for daemons to run as, in order to limit their access to the system.
Was used for programs that performed administrative tasks.
Used by programs for printing
Often used by email programs
Often used for network news servers
Often used for Unix-to-Unix Copy of files from one server to the next
Often used to allow system operators to access the system
Generally used as an account that receives all the information of troubles with the mail server
Used by NFS
Create the ${CLFS}/etc/group file by running the following command:
cat > ${CLFS}/etc/group << "EOF"
root:x:0:
bin:x:1:
sys:x:2:
kmem:x:3:
tty:x:4:
tape:x:5:
daemon:x:6:
floppy:x:7:
disk:x:8:
lp:x:9:
dialout:x:10:
audio:x:11:
video:x:12:
utmp:x:13:
usb:x:14:
cdrom:x:15:
EOF
Additional groups you may want to add
All users in this group are allowed to do administrative tasks
This group has direct access to the console
This group is allowed to use the CDRW drive
Used by MTAs (Mail Transport Agents)
Used by Network News Servers
Used by the Unix-to-Unix copy users
The default GID used by shadow for new users
This is a default group used by some programs that do not require a group
This is used by NFS
The created groups are not part of any standard—they are groups decided on in part by the requirements of the Udev configuration in the final system, and in part by common convention employed by a number of existing Linux distributions. The Linux Standard Base (LSB, available at http://www.linuxbase.org) recommends only that, besides the group “root” with a Group ID (GID) of 0, a group “bin” with a GID of 1 be present. All other group names and GIDs can be chosen freely by the system administrator since well-written programs do not depend on GID numbers, but rather use the group's name.
The login, agetty, and init programs (and others) use a number of log files to record information such as who was logged into the system and when. However, these programs will not write to the log files if they do not already exist. Initialize the log files and give them proper permissions:
touch ${CLFS}/var/run/utmp ${CLFS}/var/log/{btmp,lastlog,wtmp}
chmod -v 664 ${CLFS}/var/run/utmp ${CLFS}/var/log/lastlog
chmod -v 600 ${CLFS}/var/log/btmp
The /var/run/utmp file records the users that are currently logged in. The /var/log/wtmp file records all logins and logouts. The /var/log/lastlog file records when each user last logged in. The /var/log/btmp file records the bad login attempts.