The Linux Accountant
Useradd is a powerful command-line tool that allows system administrators to create new user accounts and set up their user environment. In this blog post, we will also cover some of the other useful commands that system administrators can use to manage user accounts on a Linux system.
To create a new user account with a specific username and home directory:
useradd -m -d /home/newuser -s /bin/bash newuser
To create a new user account with a specific UID and GID:
useradd -u 1001 -g 1001 newuser
To create a system user account without a home directory:
useradd -r -s /bin/false daemon
To create a new user account with a specific expiration date:
useradd -e 2023-12-31 newuser
To create a new user account with a specific password:
useradd -m -p $(openssl passwd -1 password) newuser
To create a user with a username that contains characters that are not allowed by default, you can use the --badname option
useradd --badname joe_schmoe!
useradd -b /opt/users -d /opt/users/joe -m joe
The following command will create a user with the username joe and the home directory /opt/users/joe
useradd -b /opt/users -d /opt/users/joe -m joe
The following command will create a user with the username joe and the home directory /home/joe, using a BTRFS subvolume for the home directory
useradd --btrfs-subvolume-home joe
The following command will create a user with the username joe and the GECOS field "Joe Schmoe,Developer":
useradd -c "Joe Schmoe,Developer" joe
The following command will print the default configuration for useradd:
useradd -D
The following command will create a user with the username joe and an expiration date of June 1, 2024:
useradd -e 2024-06-01 joe
The following command will create a user with the username joe and a password inactivity period of 30 days:
useradd -f 30 joe
The following command will create a system user with the username joe and add entries to the /etc/subuid and /etc/subgid files:
useradd -r -F -m joe
To create a new user with the username "john" and set the primary group to "staff", you can use the following command:
useradd -g staff john
To create a new user with the username "jane" and add her to the "developers" and "users" groups, you can use the following command:
useradd -G developers,users jane
To create a new user with the username "bob" and use the skeleton directory "/etc/skel2" instead of the default "/etc/skel", you can use the following command:
useradd -k /etc/skel2 bob
To create a new user with the username "alex" and set the default password expiration time to 30 days instead of the default 90 days, you can use the following command:
useradd -K PASS_MAX_DAYS=30 alex
To create a new system account with the username "ftp" and the To create a new user with a specific SELinux user, you can use the following command:UID 1001, you can use the following command:
useradd -r -u 1001 ftp
To create a new user with a custom prefix directory, you can use the following command:
useradd -P /opt/myapp/etc -m myuser
To create a new user with the zsh shell, you can use the following command:
useradd -s /bin/zsh -m myuser
To create a new user with a specific user ID, you can use the following command:
useradd -u 1001 -m myuser
To create a new user with a group of the same name, you can use the following command:
useradd -U -m myuser
To create a new user with a specific SELinux user, you can use the following command:
useradd -Z staff_u -m myuser
In conclusion, the "useradd" command is an essential tool for system administrators managing users in a network environment. It enables them to create and manage user accounts efficiently, granting or restricting access to specific system resources based on individual user needs. Additionally, by learning about other related commands like "usermod," "userdel," and "passwd," system administrators can handle critical thinking scenarios for user management and ensure the security and integrity of the network. The ability to effectively manage user accounts is crucial for any system administrator, and mastering these commands can make a significant difference in the smooth functioning of a network environment.