#!/bin/sh
#
# asuser - execute a command as the given user with the user's primary group
#
# $Id$

PATH=/usr/bin:/bin; export PATH

Die() { echo $0: fatal error: "$@"; exit 1; }

sudo_opts=
while :
do
  case "$1" in
  -*) sudo_opts="$sudo_opts $1";;
  *) break;;
  esac
  shift
done

user=$1
shift

[ $# -gt 0 ] || set ${SHELL:-bash}

Getent() { getent "$1" "$2" | awk -F: '{print $'$3'}'; }

[ -n "$user" ] || Die first argument must be a username

[ -n "`Getent passwd $user 1`" ] || Die first argument must be a valid username

group="`Getent group $user 1`"

if [ -n "$group" ]
then
  g_opt="-g $group"
else
  g_opt=
fi

home=`Getent passwd "$user" 6`

sudo $sudo_opts -u $user $g_opt env HOME=$home "$@"