#!/bin/sh

# new_msgs
# Andrew Davison (ad@ratree.psu.ac.th), August 1997

# The position of the new messages in $mspool are
# collected in $msgs and stored in $ml.mno

# The "From " lines in the current version of $mspool
# are stored in $ml.nfroms, and compared with the old
# "From " lines from previously (in $ml.ofroms). Any
# lines which are not in $ml.ofroms must be new, and
# their position are recorded in $msgs.


mspool="/var/spool/mail/ad"
ml="/home/ad/coding/mailer/mail"

from > $ml.nfroms

oldIFS="$IFS"                  # backup old separator
IFS='
'                              # make separator a newline

count=1
for line in `cat $ml.nfroms`
do
  grep -qsx "$line" $ml.ofroms     # Is $line in old froms?
  if [ $? != 0 ]                   # If no then ...
  then
    msgs="$msgs $count"
  fi
  count=`expr $count + 1`
done
IFS="$oldIFS"                  # reset separator to old value

mv -f $ml.nfroms $ml.ofroms

# echo New message numbers: "$msgs"
echo $msgs > $ml.mno