Hi folks, wanting to go lightweight, I just switched back from kdm to xdm, but I ran into a little snag, which I reported as bug FS#26395 on the bug tracker. I'm no longer sure this is actually a bug, at least not of "who". The problem: After loggin in via xdm, "who" does not show any logged in users. "who /var/run/utmp" on the other hand does show the logged in user. Using kdm, "who" and "who /var/run/utmp" both reported the same result. The reason: There's a small difference between running "who" with or without argument. When run without argument, "who" checks whether the process associated with a session in /var/run/utmp is dead or alive. If it is dead, the entry is not listed in the output. Now, when using xdm, sessreg is run from Xstartup and registers the shell running Xstartup as the PID associated with the session. The shell running Xstartup exits and then xdm fires up Xsetup to start the user's session. Since the shell running Xstartup has exited, there is no longer any process with the PID associated with the session in /var/run/utmp. Hence, who does not report this session. While this explains the source of the problem, I have no idea how to fix it. It seems that what would be needed is to run sessreg as root from a process that stays alive while the user is actually logged into the X session. kdm, for example, does in fact stay alive while the user is logged in. So does xdm, but the PID recorded in /var/run/utmp is not the one of xdm but of the shell it spawns to run Xsetup. Any suggestions would be greatly appreciated. Cheers, Norbert
