#!/bin/sh

# Jens Getreu

# This script executes commands
# under X11
# in the name of another user.
#
# usage: sudox -u <clientuser> <command>
# example: sudox -u mynobody xeyes

# Ideas taken from:
#       Remote X Apps mini-HOWTO
#       Vincent Zweije, zweije@xs4all.nl

# In order to allow all members of %users to
# execute locally every command you will need to
# add this line to /etc/sudoers:
#       %users   LOCAL=(mynobody) NOPASSWD:ALL


if  [ $# -lt 3 ] || [ $1 != "-u" ] 
then echo "usage: `basename $0` -u <clientuser> <command>" >&2
     exit 2
fi
shift

CLIENTUSER="$1"
CLIENTHOME=$(grep "^$CLIENTUSER:" /etc/passwd|cut -d: -f 6)
shift

# FD 4 becomes stdin too
exec 4>&0

xauth nlist "$DISPLAY" | {

    # FD 3 becomes xauth output
    # FD 0 becomes stdin again
    # FD 4 is closed
    exec 3>&0 0>&4 4>&-

    exec /usr/bin/sudo -H -u "$CLIENTUSER" \
          /usr/X11R6/bin/xauth -f "$CLIENTHOME"/.Xauthority nmerge - <&3 
}

exec echo "env DISPLAY=$DISPLAY XAUTHORITY=${CLIENTHOME}/.Xauthority $*" | sudo -H -i -u "$CLIENTUSER"