w: shows more users than `w` from procps-ng

[cakebaker]

Our implementation of w shows more users than w from procps-ng:

$ cargo run -q w
USER     TTY      LOGIN@   IDLE   JCPU   PCPU WHAT
dho      tty1     07:29    TODO   0.08   0.08 /usr/bin/startplasma-wayland
dho      pts/0    07:29    TODO   5127.583.13 /usr/bin/kded6
dho      pts/1    07:29    TODO   87.50  0.01 /bin/bash
dho      pts/2    07:32    TODO   1.95   0.05 /bin/bash
dho      pts/3    07:32    TODO   0.36   0.24 /bin/bash
dho      pts/4    07:32    TODO   0.19   0.04 /bin/bash
dho      pts/5    07:32    TODO   0.06   0.06 /bin/bash

$ w
 16:31:58 up  9:03,  2 users,  load average: 0.26, 0.24, 0.20
USER     TTY       LOGIN@   IDLE   JCPU   PCPU  WHAT
dho      tty1      07:29    9:03m  0.08s  0.08s /usr/bin/startplasma-wayland
dho                07:29    8:59m  0.00s  0.95s /usr/lib/systemd/systemd --user

[aisuneko]

I think this is because our implementation fetches the list of users via utmpx (utmp/wtmp login records):

     Running `target/debug/procps w`
USER     TTY      LOGIN@   IDLE   JCPU   PCPU WHAT
aisuneko tty2     Sun23    10:18m 0.22   0.2  /usr/bin/startplasma-wayland
aisuneko pts/0    Sun23    10:18m 1303.853.35 /usr/bin/kded6
aisuneko pts/2    Sun23    10:13m 0.46   0.37 /usr/bin/fish
aisuneko pts/3    Sun23    10:13m 0.46   0.09 sudotio/dev/ttyACM0
aisuneko pts/4    Sun23    10:10m 0.04   0.04 /usr/bin/fish
aisuneko pts/1    09:48    37.05s 0.15   0.15 /usr/bin/fish
[aisuneko@liquidice procps]$ last -f /var/run/utmp
aisuneko pts/1        :0               Mon Mar 24 09:48   still logged in
aisuneko pts/4        :0               Sun Mar 23 23:40   still logged in
aisuneko pts/3        :0               Sun Mar 23 23:40   still logged in
aisuneko pts/2        :0               Sun Mar 23 23:36   still logged in
aisuneko pts/0        :0               Sun Mar 23 23:36   still logged in
aisuneko tty2                          Sun Mar 23 23:36   still logged in
reboot   system boot  6.13.6-arch1-1   Sun Mar 23 23:36   still running

utmp begins Sun Mar 23 23:36:04 2025

while procps-ng also provides a systemd-based approach (specifically, in sd-login) which appears to be enabled by default on builds provided by systemd-based distros. A proof of this is that the binary's behavior is consistent with ours on non-systemd distros (tested on Alpine).

[Bluemangoo]

confused. It works on my machine.

$ cargo run -q w
 16:40:07 up  6:48,  4 users,  load average: 1.05, 0.97, 1.00
USER     TTY       LOGIN@   IDLE   JCPU   PCPU  WHAT
bluemangootty1      09:51    6:48m  0.05   0.05  /usr/bin/startplasma-wayland
bluemangoopts/0     09:51    6:48m  7704.296.97  /usr/bin/kded5
bluemangoopts/2     16:28    10:42  0.43   0.4   /usr/bin/zsh
bluemangoopts/3     16:28    11:15  0.20   0.17  /usr/bin/zsh
$ w
 16:40:08 up  6:48,  1 users,  load average: 1.05, 0.97, 1.00
USER     TTY       LOGIN@   IDLE   JCPU   PCPU  WHAT
bluemang tty1      09:51    6:48m  0.05s  0.05s /usr/bin/startplasma-wayland
bluemang pts/0     09:51    6:48m  0.00s  6.97s /usr/bin/kded5
bluemang pts/2     16:28   10:44   0.43s  0.40s /usr/bin/zsh
bluemang pts/3     16:28   11:17   0.20s  0.17s /usr/bin/zsh

w from procps-ng 4.0.5, build from source(from debian); Debian 12(bookworm)

It seems that your w ignores pts. Mine dosen't. can you provide your procps-ng version? It probably caused by the different procps versions.

by the way, session list from systemd via sd_get_sessions only contains one on my machine:

user tty state type
bluemangoo tty1 active wayland

[Franklin-Qi]

On my machine, cargo run -q w does not retrieve any information. The w command needs to be changed.

$ dpkg -l |grep procps
ii  procps                                                   2:4.0.4-8ubuntu3                           amd64        /proc file system utilities

$ w
 17:32:18 up  7:49,  1 user,  load average: 1.31, 1.30, 1.34
USER     TTY      来自           LOGIN@   IDLE   JCPU   PCPU  WHAT
ysq      tty1     -                09:44    7:49m  0.06s  0.06s /usr/bin/startplasma-wayland

$ cargo run -q w 
 17:32:26 up  7:49,  0 user,  load average: 1.28, 1.29, 1.34
USER     TTY       LOGIN@   IDLE   JCPU   PCPU  WHAT