`w` vs`who` commands.

In Unix-like operating systems, the w and the who are command-line utilities used to display information about users currently logged into the system.
While they achieve similar objectives, their level of detail and information varies.

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Here's a breakdown of the differences between the two:

w Command

The w command provides a more detailed overview of the system's current state, including information about users and their actions.

Here's an example:

$ w

 23:05:03 up 25 days,  3:24,  3 users,  load average: 0.23, 0.35, 0.61
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
snub     pts/0    192.168.1.3     11:23    1:03m  0.00s  0.00s bash
monkey   pts/1    192.168.1.4     11:34    3:11m  0.01s  0.01s ssh
ghost    pts/2    192.168.1.5     20:09    4:15m  0.02s  0.02s ssh

• Time and Uptime: Displays the current time, how long the system has been running (uptime), and the number of users logged in.
• Load Average: Shows the system's load average for the past 1, 5, and 15 minutes.
• USER: The username of the logged-in user.
• TTY: The terminal associated with the user session.
• FROM: The remote host or IP address from where the user is logged in.
• LOGIN@: The time when the user logged in.
• IDLE: The idle time (how long since the user last interacted with the terminal).
• JCPU: The total CPU time used by all processes attached to the terminal.
• PCPU: The CPU time used by the current process.
• WHAT: The command currently being executed by the user.

who Command

The who command provides a simpler and more focused output, showing who is currently logged into the system.

Here's an example:

$ who
snub     pts/0        2024-07-04 11:23 (192.168.1.3)
monkey   pts/1        2024-07-04 11:34 (192.168.1.4)
ghost    pts/2        2024-07-04 20:09 (192.168.1.5)

• USER: The username of the logged-in user.
• TTY: The terminal associated with the user session.
• DATE and TIME: The date and time when the user logged in.
• HOST: The remote host or IP address from where the user is logged in (if applicable).

Comparison

• Detail Level:
  • w: Provides more detailed information about system load, user activity, and processes.
  • who: Provides basic information about users who are currently logged in.
• Use Cases:
  • w: Useful for administrators who need a quick overview of system activity, including what users are doing and the system load.
  • who: Useful for quickly checking which users are currently logged into the system without additional details.

Using Options:

• w with options:

w -h    # Hide the header
w -s    # Short format, does not display JCPU and PCPU times

• who with options:

who -b  # Show the last system boot time
who -m  # Show information only about the current terminal
who -q  # Quick output, only displays usernames and number of users

By understanding the differences between the w and who commands, you can choose the one that best fits the level of detail you need regarding logged-in users and system activity.

Thanks for checking in, and we hope this tip was helpful!