#!/usr/dt/bin/dtksh

#rst contains the user names from the roster file

rst=`cut -d ":" -f 1 /accounts/classes/(prof name)/c275/intro/roster`

#This is the first case. No args entered = we check to see if anyone from roster is logged on

if [ $# -eq 0 ]; then
   echo "No args entered, checking roster file..."
   for i in $rst; do
       finger | cut -c 1-6 | grep $i > /dev/null
       if [ $? -eq 0 ]; then
           echo "$i is on"
       fi
   done

#This is the second case. First checks to see if the arg entered is a valid user, then checks to see if they are online

else
   for i; do
       id $i > /dev/null
       if [ $? -eq 0 ]; then
           finger | cut -c 1-6 | grep $i > /dev/null
           if [ $? -eq 0 ]; then
               echo "$i is on"
           fi
       else
           echo "$i is not a user"
       fi
   done
fi

#This script is intended to alert the user when anyone from a list of users (args to the script) is online on admiral.
#The script optionally accepts a message to be sent to the user when someone is by utilizing the -m option.
#The script optionally accepts a date to run the script at. However there is a limitation due to at jobs not working correctly at the moment (outlined below)
#The date arg entered must be in the form of something like: TueMar121200 (DayMonDay#Time#)
#The correct execution of the script would ideally run it using '&' to run it in the background, perhaps nohup to let it run while logged off admiral.

USAGE="Correct usage: alert -w [optional date] -m [optional message] [user list]"

if [ $# -lt 1 ]; then
   echo "Must enter at least 1 user to search for" && exit 1
fi

while getopts w:m: var
do
   case $var in
   w)      wflag=1
           wval="$OPTARG";;
   m)      mflag=1
           mval="$OPTARG";;
   ?)      echo $USAGE && exit 0
   esac
done

shift $(($OPTIND -1))

if [ ! -z "wflag" ]; then
   while ( sleep 60 ); do
       time=`date | awk -F" " '{print $1 $2 $3 $4}' | awk -F":" '{print $1 $2}' | sed "s/://g"`
       if [ $time -eq "$wval" ]; then
           break
       fi
   done
fi

while ( sleep 66 ); do
   for i; do
       id $i > /dev/null
       if [ $? -eq 0 ]; then
           finger | grep ^$i > /dev/null
           if [ $? -eq 0 ]; then
               finger | grep ^$USER
               if [ $? -eq 0 ]; then
                   banner $i IS ON
                   if [ ! -z "$mflag" ]; then
                       echo "$mval" | write $USER
                   fi
               else banner "$i IS ON" | elm -s $mval $USER
               fi
               if [ $# -eq 1 ]; then
                   exit 0
               fi
               set $(echo $@ | sed "s/$i//")
           fi
       else echo "$i is not a user. Please re-run the script with a correct user name [Consider searching for the username with the id command]" && echo "\n$USAGE" && exit 0
       fi
   done
done