#! /bin/ksh

# Get directory as parameter, list all files in this directory,
# print them in reverse order and let the user select one.
# then that file will be presented with either tail -f or less/more.
# Enter will bring the user back to the dialog where he/she can also 
# quit.
#
# Copyright 2002
# Chr. Clemens Lee, http://www.kclee.com/clemens/
# 2002-01-17, last modified: $Date: 2006/11/18 17:17:09 $, $Revision: 1.2 $
# Distributed under the Gnu Public License (GPL).

logdir=$1
test -z "$logdir" && echo "logwatcher: error: no log directory specified" && exit 2

process=$$
tempfile=/tmp/_log_list$process
viewer=tail

while true
do
   echo Log Watcher

   # Print file list in reverse order with line numbers, 
   # save file list in temp file.
   (ls -lt $logdir > $tempfile) && tail -$(expr $(wc -l $tempfile | cut -c0-8) - 1) $tempfile | nl | sort -nr

   # user command
   echo "q for quit, m for more, t for tail -f (default is $viewer)"
   read selection

   # skip empty input
   if test -z "$selection"
   then
        continue
   fi

   #
   # process quit or viewer selection
   #
   if test $selection = "q"
   then
      rm ${tempfile}

      exit 0
   fi
   if test $selection = "t"
   then
      viewer=tail

      continue
   fi

   if test $selection = "m"
   then
      viewer=more

      continue        
   fi

   # skip garbage
   if [[ "$selection" < "1" ]]
   then
        continue
   fi
   if [[ "$selection" > "999999999" ]]
   then
        continue
   fi
   maxline=$(expr $(wc -l $tempfile | cut -c0-8) - 1)
   if (( $selection < 1 ))
   then
        continue
   fi
   if (( $selection > $maxline ))
   then
        continue
   fi

   # select file
   line=$(tail -$(expr $(wc -l $tempfile | cut -c0-8) - $selection) $tempfile | head -1)
   file=${line##* }
   test -f $logdir/$file || continue

   #
   # view file
   #

   if test $viewer = "tail"
   then
      echo
      echo "<enter> to quit tail"
      echo
      tail -f $logdir/$file &
      TAIL_PID=$!

      read stop_tail

      # kill tail before printing file list again
      kill $TAIL_PID
   fi

   if test $viewer = "more"
   then
      # use less if it exists, otherwise use more
      whence less > /dev/null && less $logdir/$file
      whence less > /dev/null || more $logdir/$file

      # to have a clean start again
      echo
   fi

done