12 Ways to Find User Account Info and Login Details in Linux-程序员充电站

This article will show you useful ways to find information about users on a Linux system. Here we’ll describe commands to get a user’s account details, show login details as well what users are doing on the system.

If you want to add or create users in Linux, use the useradd command, and to modify or change any attributes of an already created user account, use the usermod command via the command line.

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We’ll start by looking at 12 useful commands to find a user’s account information, then proceed to explain commands to view login details in the Linux system.

Table of Contents

1. id Command – Show User and Group IDs
2. groups Command – View User Group Memberships
3. finger Command – Show User Information
4. getent Command – Fetch User Info from System Database
5. grep Command – Search for Patterns or Specific Text in Files
6. lslogins Command – Display User Information in Linux
7. users Command – List Current Logged-In Users on Linux
8. who Command – Show Information Of Currently Logged-In Users
9. w Command – Show Currently Logged-In User Activity
10. last Command – Show Most Recent Login Session
11. lastb Command – Show Failed Login Attempts
12. lastlog Command – List User Login Information

1. id Command – Show User and Group IDs

Theidis a simple command line utility for displaying a real and effective user and group IDs identity information for the current user or specified user.

$ id tecmint

View User and Group ID’s of Current User

2. groups Command – View User Group Memberships

Thegroupscommand is used to display the group memberships for a user. It lists all the groups that a user belongs to, including both primary and supplementary groups.

$ groups tecmint

Check User Groups in Linux

3. finger Command – Show User Information

Thefingercommand is used to search for information about a user on Linux, which includes detailed information about a specific user or a list of users, including their login name, real name, terminal, idle time, login time, and other relevant details.

Thefingercommand doesn’t come pre-installed on many Linux distributions, you need to install it using your default package manager as shown.

$ sudo apt install finger [OnDebian, Ubuntu and Mint] $ sudo yum install finger [OnRHEL/CentOS/FedoraandRocky/AlmaLinux] $ sudo emerge -a sys-apps/finger [OnGentoo Linux] $ sudo apk add finger [OnAlpine Linux] $ sudo pacman -S finger [OnArch Linux] $ sudo zypper install finger [OnOpenSUSE]

It shows a user’s real name; home directory; shell; login: name, time; and so much more as shown below.

$ finger tecmint

Check User Info in Linux

4. getent Command – Fetch User Info from System Database

Thegetentcommand is used to retrieve information from various databases, including the system user and group databases. It can be used to retrieve information about users, groups, hosts, networks, protocols, and other system entities that are stored in database files like/etc/passwd,/etc/group,/etc/hosts, etc.

To get a user’s account details, use thepasswddatabase and theusernameas follows.

$ getent passwd tecmint

Fetch User Info in Linux

5. grep Command – Search for Patterns or Specific Text in Files

The grep command is a powerful command used to search for patterns or specific text in files. It allows you to filter and extract lines from text based on matching patterns. The name “grep” stands for “Global Regular Expression Print“.

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You can usegrepto find information about a specific user from the system accounts file:/etc/passwdas shown below.

$ grep -i tecmint /etc/passwd

Grep – Fetch User Info in Linux

6. lslogins Command – Display User Information in Linux

Thelsloginscommand shows information about known users in the system, which typically includes details such as the username, UID (User ID), GID (Group ID), home directory, shell, last login time, and more, depending on the options used and the system configuration.

$ lslogins -u tecmint $ lslogins -u

Display User Info in Linux

7. users Command – List Current Logged-In Users on Linux

Theuserscommand is used to display the list of currently logged-in users on the Linux system.

$ users

Show Current Logged in Users in Linux

8. who Command – Show Information Of Currently Logged-In Users

Thewhocommand is used to display users who are logged on to the system, including the username, terminal, login time, and remote host from which the user is logged in.

$ who -u

Show Current Logged-in Users

9. w Command – Show Currently Logged-In User Activity

Thewcommand shows a summary of the currently logged-in users and their activity, which displays the login session, including the username, terminal, login time, idle time, JCPU (total CPU time used by all processes), PCPU (CPU time used by the current process), and the command or process running on the terminal.

$ w

Show Currently Logged-In User Activity

10. last Command – Show Most Recent Login Session

Thelastcommand displays a list of the most recent login sessions, which includes information about the users who have logged in, their login times, and the terminals or remote hosts they used for login.

$ last

Show Most Recent Login Sessions

To show all the users who were present at a specified time, use the-poption as follows.

$ last -ap now

List Most Recent User Logins

11. lastb Command – Show Failed Login Attempts

Thelastbcommand is used to display a list of the last failed login attempts on the system. It reads from the system log file that records failed login attempts, typically stored in /var/log/btmp.

$ lastb

Show Failed Login Attempts in Linux

12. lastlog Command – List User Login Information

lastlog commandis used to find the details of the most recent login information for all users or a specific user on the system, which provides details about the last login time and location for each user.