xdmshell(8)

1XDMSHELL(8)                 System Manager's Manual                XDMSHELL(8)
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NAME

6       xdmshell - shell for starting xdm on login
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SYNOPSIS

9       /usr/bin/xdmshell
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DESCRIPTION

12       Xdmshell  can be used on systems that are configured to start a console
13       in text mode by default, to allow users to start the X display  manager
14       by logging in as a special user with the shell set to the xdmshell pro‐
15       gram.
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17       Many servers set the keyboard to do non-blocking I/O under the  assump‐
18       tion  that  they are the only programs attempting to read from the key‐
19       board.  Unfortunately, some versions of getty(8) will immediately see a
20       continuous  stream of zero-length reads which they interpret as end-of-
21       file indicators.  Eventually, init(8) will disable logins on that  line
22       until somebody types the following as root:
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24       On  some platforms, one alternative is to disable logins on the console
25       and always run xdm(8) from /etc/inittab.
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27       Another approach is to set up an account whose shell  is  the  xdmshell
28       program  found  in the xdm distribution.  This program is not installed
29       by default so that site administrators will examine it  to  see  if  it
30       meets  their  needs.   The xdmshell utility makes sure that it is being
31       run from the appropriate type of terminal, starts xdm, waits for it  to
32       finish, and then resets the console if necessary.  If the xdm resources
33       file (specified by the DisplayManager*resources entry in the xdm-config
34       file)  contains  a  binding  to the abort-display action similar to the
35       following
36              xlogin*login.translations:  #override   Ctrl<Key>R:   abort-dis‐
37              play()
38       the  console  can  then by restored by pressing the indicated key (Con‐
39       trol-R in the above example) in the xdm login window.
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41       The xdmshell program is usually installed setuid to root but executable
42       only by members of a special group, of which the only member is the ac‐
43       count which has xdmshell as its shell:
44              %  grep xdm /etc/passwd
45              x::101:51:Account for starting up X:/tmp:/usr/bin/xdmshell
46              %  grep 51 /etc/group
47              xdmgrp:*:51:
48              %  ls -lg /usr/bin/xdmshell
49              -rws--x---   1 root     xdmgrp     20338 Nov  1 01:32 /usr/bin/xdmshell
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51       If the xdm resources have not been configured to have a  key  bound  to
52       the  abort-display()  action, there will be no way for general users to
53       login to the console directly.  Whether or not this  is  desirable  de‐
54       pends on the particular site.
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NAME

SYNOPSIS

DESCRIPTION

SEE ALSO