dm.8

早期freebsd实现

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.\"     @(#)dm.8	8.1 (Berkeley) 5/31/93
.\"
.Dd May 31, 1993
.Dt DM 8
.Os
.Sh NAME
.Nm dm
.Nd dungeon master
.Sh SYNOPSIS
.Nm ln
.Fl s Cm dm Ar game
.Sh DESCRIPTION
.Nm Dm
is a program used to regulate game playing.
.Nm Dm
expects to be invoked with the name of a game that a user wishes to play.
This is done by creating symbolic links to
.Nm dm ,
in the directory
.Pa /usr/games
for all of the regulated games.
The actual binaries for these games should be placed in a
.Dq hidden
directory,
.Pa /usr/games/hide ,
that may only be accessed by the
.Nm dm
program.
.Nm Dm
determines if the requested game is available and, if so, runs it.
The file
.Pa /etc/dm.conf
controls the conditions under which games may
be run.
.Pp
The file
.Pa /etc/nogames
may be used to
.Dq turn off
game playing.
If the file exists, no game playing is allowed; the contents of the file
will be displayed to any user requesting a game.
.Sh FILES
.Bl -tag -width /var/log/games.log -compact
.It Pa /etc/dm.conf
configuration file
.It Pa /etc/nogames
turns off game playing
.It Pa /usr/games/hide
directory of ``real'' binaries
.It Pa /var/log/games.log
game logging file
.El
.Sh SEE ALSO
.Xr dm.conf 5
.Sh BUGS
Two problems result from
.Nm dm
running the games setuid
.Dq games .
First, all games that allow users to run
.Tn UNIX
commands should carefully
set both the real and effective user id's immediately before executing
those commands.  Probably more important is that
.Nm dm
never be setuid
anything but
.Dq games
so that compromising a game will result only in
the user's ability to play games at will.  Secondly, games which previously
had no reason to run setuid and which accessed user files may have to
be modified.
.Sh HISTORY
The
.Nm dm
command appeared in
.Bx 4.3 tahoe .