#!/bin/bash

[ -r /etc/default/vyatta ] && source /etc/default/vyatta

declare cur_tty=$(ps -o tty= |head -n1)
declare cur_uid=($(ps -o ruser= n |head -n1))
declare cur_user=$(grep "[^:]\+:[^:]*:${cur_uid[0]}:" /etc/passwd \
                   | cut -d ':' -f 1)
declare -a ulist=( $(ps -a -o args,tty,ruser n \
                     | grep "^newgrp $VYATTA_CFG_GROUP_NAME" | cut -c 29-) )

for (( i = 0; i < ${#ulist[@]}; i += 2 )); do
  utty=${ulist[i]}
  if [ "$utty" == "$cur_tty" ]; then
    continue
  fi
  user=$(grep "[^:]\+:[^:]*:${ulist[i+1]}:" /etc/passwd | cut -d ':' -f 1)
  sudo write $user $utty <<EOF
Active configuration has been changed by user '$cur_user' on '$cur_tty'.
Please make sure you do not have conflicting changes. You can also discard
the current changes by issuing 'exit discard'.
EOF
done