xdmshell

XDMSHELL(1)                 General Commands Manual                XDMSHELL(1)



NAME
       xdmshell - shell for starting xdm on login

SYNOPSIS
       /usr/bin/xdmshell

DESCRIPTION
       Xdmshell can be used on systems that are configured to start a console
       in text mode by default, to allow users to start the X display manager
       by logging in as a special user with the shell set to the xdmshell
       program.

       Many servers set the keyboard to do non-blocking I/O under the
       assumption that they are the only programs attempting to read from the
       keyboard.  Unfortunately, some versions of getty(8) will immediately
       see a continuous stream of zero-length reads which they interpret as
       end-of-file indicators.  Eventually, init(8) will disable logins on
       that line until somebody types the following as root:

       On some platforms, one alternative is to disable logins on the console
       and always run xdm(1) from /etc/inittab.

       Another approach is to set up an account whose shell is the xdmshell
       program found in the xdm distribution.  This program is not installed
       by default so that site administrators will examine it to see if it
       meets their needs.  The xdmshell utility makes sure that it is being
       run from the appropriate type of terminal, starts xdm, waits for it to
       finish, and then resets the console if necessary.  If the xdm resources
       file (specified by the DisplayManager*resources entry in the xdm-config
       file) contains a binding to the abort-display action similar to the
       following
              xlogin*login.translations: #override  Ctrl<Key>R: abort-
              display()
       the console can then by restored by pressing the indicated key
       (Control-R in the above example) in the xdm login window.

       The xdmshell program is usually installed setuid to root but executable
       only by members of a special group, of which the only member is the
       account which has xdmshell as its shell:
              %  grep xdm /etc/passwd
              x::101:51:Account for starting up X:/tmp:/usr/bin/xdmshell
              %  grep 51 /etc/group
              xdmgrp:*:51:
              %  ls -lg /usr/bin/xdmshell
              -rws--x---   1 root     xdmgrp     20338 Nov  1 01:32 /usr/bin/xdmshell

       If the xdm resources have not been configured to have a key bound to
       the abort-display() action, there will be no way for general users to
       login to the console directly.  Whether or not this is desirable
       depends on the particular site.

SEE ALSO
       X(7), xdm(1), xinit(1)



X Version 11                      xdm 1.1.11                       XDMSHELL(1)