sessreg - manage utmp/wtmp entries for non-init clients
] [-u utmp-file
] [-l line-name
] [-h host-name
] [-x Xservers-file
] [-t ttys-file
] [-V] [-a]
is a simple program for managing utmp/wtmp and lastlog entries
for xdm sessions.
System V has a better interface to utmp than BSD; it dynamically allocates
entries in the file, instead of writing them at fixed positions indexed by
position in /etc/ttys
To manage BSD-style utmp files, sessreg
has two strategies. In
conjunction with xdm, the -x option counts the number of lines in
and then adds to that the number of the line in the Xservers
file which specifies the display. The display name must be specified as the
"line-name" using the -l option. This sum is used as the
"slot-number" in the utmp file that this entry will be written at.
In the more general case, the -s option specifies the slot-number directly. If
for some strange reason your system uses a file other than /etc/ttys
manage init, the -t option can direct sessreg
to look elsewhere for a
count of terminal sessions.
Conversely, System V managers will not ever need to use these options (-x, -s
and -t). To make the program easier to document and explain, sessreg
accepts the BSD-specific flags in the System V environment and ignores them.
BSD and Linux also have a host-name field in the utmp file which doesn't exist
in System V. This option is also ignored by the System V version of
In Xstartup, place a call like:
sessreg -a -l $DISPLAY -x /etc/X11/xdm/Xservers $USER
and in Xreset:
sessreg -d -l $DISPLAY -x /etc/X11/xdm/Xservers $USER
- -w wtmp-file
- This specifies an alternate wtmp file, instead of /var/log/wtmp.
The special name "none" disables writing records to the wtmp
- -u utmp-file
- This specifies an alternate utmp file, instead of /var/run/utmp.
The special name "none" disables writing records to the utmp
- -L lastlog-file
- This specifies an alternate lastlog file, instead of
/var/log/lastlog, if the platform supports lastlog files. The
special name "none" disables writing records to the lastlog
- -l line-name
- This describes the "line" name of the entry. For terminal
sessions, this is the final pathname segment of the terminal device
filename (e.g. ttyd0). For X sessions, it should probably be the local
display name given to the users session (e.g. :0). If none is specified,
the terminal name will be determined with ttyname(3) and stripped of
- -h host-name
- This is set to indicate that the session was initiated from a remote host.
In typical xdm usage, this options is not used.
- -s slot-number
- Each potential session has a unique slot number in BSD systems, most are
identified by the position of the line-name in the
/etc/ttysfile. This option overrides the default position
determined with ttyslot(3). This option is inappropriate for use with xdm,
the -x option is more useful.
- -x Xservers-file
- As X sessions are one-per-display, and each display is entered in this
file, this options sets the slot-number to be the number of lines
in the ttys-file plus the index into this file that the
line-name is found.
- -t ttys-file
- This specifies an alternate file which the -x option will use to
count the number of terminal sessions on a host.
- This option causes the command to print its version and exit.
- This session should be added to utmp/wtmp.
- This session should be deleted from utmp/wtmp. One of -a/-d must be
Keith Packard, MIT X Consortium