How to delete group in Linux

1. Delete a group named sales that exist on Linux, run: sudo groupdel sales
2. Another option to remove a group called ftpuser in Linux, sudo delgroup ftpusers
3. To view all group names on Linux, run: cat /etc/group
4. Print the groups a user say vivek is in: groups vivek

Let us see some common examples in details.

How to remove group in Linux using groupdel command

The syntax for the groupdel command is:
sudo groupdel {group-name-here}
To delete a group named staff, enter:
sudo groupdel staff
One can view a list of groups on Linux using either cat command or grep command/egrep command and then we can use groupdel:
cat /etc/group
grep '^sales' /etc/group
egrep '^(users|root|sales)' /etc/group
Use the wc command to count number of groups in your Linux server:
wc -l /etc/group

To delete a group called ftpusers, enter:
sudo groupdel ftpusers
Force removal of the primary group of a user by passing the -f option:
sudo groupdel -f admins

Deleting a group in Linux using delgroup command

In this example, you are going to delete a group named sales using delgroup. The syntax is:
sudo delgroup {group}
sudo delgroup --group {group}
sudo delgroup sales
grep '^sales' /etc/group

Another option is to only delete if user/group is a system user/group. This avoids accidentally deleting non-system users/groups. Hence, we must use the same option:
sudo delgroup --system --group wwwusers
Want to backup files before removing any group? Try:
sudo delgroup --backup --group wwwusers

How to remove the user from a group

The syntax is as follows to delete the user named tom from a group called cartoons:
sudo deluser {user} {group}
sudo deluser tom cartoons

View config file

The file named /etc/deluser.conf contains defaults for the programs deluser command and delgroup command. One can use the cat command to see contains, enter:
cat /etc/deluser.conf

# /etc/deluser.conf: `deluser' configuration.
 
# Remove home directory and mail spool when user is removed
REMOVE_HOME = 0
 
# Remove all files on the system owned by the user to be removed
REMOVE_ALL_FILES = 0
 
# Backup files before removing them. This options has only an effect if
# REMOVE_HOME or REMOVE_ALL_FILES is set.
BACKUP = 0
 
# target directory for the backup file
BACKUP_TO = "."
 
# delete a group even there are still users in this group
ONLY_IF_EMPTY = 0
 
# exclude these filesystem types when searching for files of a user to backup
EXCLUDE_FSTYPES = "(proc|sysfs|usbfs|devpts|tmpfs|afs)"

Conclusion

This page explained the groupdel/delgroup commands that modifies the system account files /etc/group and others to remove the group. Please note that the given group must exist on your machine when you execute the groupdel command. The above commands works on all Linux distros such as RHEL, Fedora, CentOS, Debian, Ubuntu, Arch Linux and more. Please see the following man pages or read it online here:
man 8 groupdel
man 8 delgroup