Introduction
In the world of Linux, the ‘who’ command is a handy tool used to display information about currently logged-in users on the system. It provides details such as username, terminal, login time, and more. Let’s dive deeper into how this command can be utilized effectively.
Syntax
The basic syntax of the ‘who’ command is quite simple:
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who [OPTION]... [FILE]...
Here, the OPTIONS can be used to customize the output according to your requirements. You can specify a file as an argument to display the users logged in from a particular file.
Example codes
- To display a basic list of currently logged-in users:
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who
This will show the username, terminal, and login time for each user.
- To display detailed information about the users:
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who -a
This will provide additional details such as system boot time, idle time, and process ID.
- To display the hostname along with user information:
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who -H
This will show the hostname in the output along with other details.
Applicable versions
The ‘who’ command is available on most Unix-based systems, including Linux distributions. It is a standard command and comes pre-installed on these systems. You can use it on popular distributions like Ubuntu, CentOS, Fedora, and more.
Conclusion
In conclusion, the ‘who’ command is a useful tool for system administrators to monitor user activity on a Linux system. By understanding its syntax and options, you can gather relevant information about logged-in users efficiently. Experiment with different options to customize the output according to your needs. Mastering this command will help you keep track of user sessions and manage your system effectively.