`w` Command Bug in Ubuntu 24.04 Affecting `ls-users` Script

[YuZhong-Chen]

Summary

The w command in Ubuntu 24.04 has multiple bugs that cause incorrect output for TTY, idle time, and login information. This affects the ls-users script which relies on w command output to display currently logged-in users.

• base-env/Script/server_status/ls-users

  Line 97 in 5dde6dc

  CURRENTLY_LOGGED_IN_USERS=$(w -h 2>/dev/null | awk '{print $1}' | sort -u)

• base-env/Script/server_status/ls-users

  Line 112 in 5dde6dc

  current_info=$(w -h | grep "^${username} " | head -1)

Problem Description

The w command in Ubuntu 24.04 (procps version 2:4.0.4-4ubuntu3.2) has multiple bugs:

• Missing TTY column: TTY information is not displayed (empty column)
• Incorrect idle time: Shows incorrect idle times for all users
• Incorrect login time: Login time display is incorrect

Reference

• w command shows incorrect idle time for all users
• w doesn't show TTYs
• w command shows incorrect idle time and missing logins
• Why is the command w in Ubuntu 24.04 different than older versions

Conclusion

Given that the bug has minimal impact, building from source seems unnecessary.
Perhaps we can simply wait for Ubuntu to release an official fix.

[YuZhong-Chen]

Note:
I have observed that sessions established via Google Antigravity are not being captured by standard system utilities such as w, last, or lastlog. This suggests that Antigravity might be connecting without allocating a pseudo-terminal (PTY) or potentially bypassing the utmp logging and PAM session modules that typically record logins.

Consequently, these active users appear "invisible" to traditional monitoring commands. To track these sessions on our servers, we currently have to rely on identifying sshd processes via ps aux | grep sshd or inspecting the auth.log. We may need to develop a more robust approach in the future to handle these types of cases.