w - Linux


The w command in Linux displays information about the system users currently logged in, their processes, and system load average. It provides a quick snapshot of user activity and system performance, making it useful in system monitoring, especially in multi-user environments.


The basic syntax of the w command is as follows:

w [options] [user]

Where user is optional and specifies to show information only for the given user.


  • -h, --no-header: Hide the header that normally shows at the top of the output.
  • -u, --no-current: Ignores the username while figuring out the current process and CPU times.
  • -s, --short: Uses the short format without the login, JCPU, or PCPU times.
  • -f, --from: Displays the from (remote hostname) field. This is sometimes hidden by default for screen space.
  • -V, --version: Displays version information and exits.

The default behavior without any options is to display the header and information about all users, showing their from field where applicable.


  1. Basic Usage:
    Show information about all currently logged-in users:

  2. Hide Header:
    To view the information without a header:

    w -h
  3. Short Format:
    Output in a shorter format:

    w -s
  4. Specific User:
    Display information only for a particular user (e.g., john):

    w john

Common Issues

  • Incorrect Permissions: The w command may require certain permissions to view all data accurately. Running it without sufficient permissions could result in incomplete results.
  • Overload of Information: In environments with many users, the output can be overwhelming. Using flags to limit the output (like -s or filtering by user) can be helpful.


The w command can be combined with other commands to script or automate system monitoring tasks. For example:

echo "Current system load and user activity:"; w -h; uptime

This script prints a custom message followed by the current user activities and system uptime, useful for regular status checks.

  • who: Shows who is logged on.
  • uptime: Tells how long the system has been running plus the number of users and system load.
  • top: Provides a dynamic real-time view of running processes.

For further reading and more detailed information about the w command and its usage, consult the man pages by running man w in the terminal.