Sessreg is a simple program for managing utmp/wtmp
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
/etc/ttys
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
to 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
sessreg.
USAGE
In Xstartup, place a call like:
sessreg -a -l $DISPLAY -x /etc/X11/xdm/Xservers $USER
This specifies an alternate wtmp file, instead of
/var/log/wtmp.
The special name "none" disables writing records to the wtmp file.
-uutmp-file
This specifies an alternate utmp file, instead of
/var/run/utmp.
The special name "none" disables writing records to the utmp file.
-lline-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 leading
components.
-hhost-name
This is set for BSD hosts to indicate that the session was initiated from
a remote host. In typical xdm usage, this options is not used.
-sslot-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.
-xXservers-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.
-tttys-file
This specifies an alternate file which the -x option will use to count
the number of terminal sessions on a host.
-a
This session should be added to utmp/wtmp.
-d
This session should be deleted from utmp/wtmp. One of -a/-d must
be specified.
