#! /bin/ksh
USAGE='USAGE: replace_link  FILE_PATH DEST_PATH
   FILE_PATH should be a link whose ultimate desitnation is DEST_PATH.
   Replace FILE_PATH with a link to DEST_PATH.
'
# (C) Copyright 1995 by Michael Coulter.  All rights reserved.

# Process parameters
   if [ $# -ne 2 ]
   then
      echo "$USAGE" >&2
      echo "Expected 2 arguments, got $#" >&2
      exit 1
   fi
   FILE_PATH="$1"; shift
   DEST_PATH="$1"; shift
   ##echo "replace_link: At 1, DEST_PATH is $DEST_PATH"
   if [ ! -L "$FILE_PATH" ]
   then
      echo "$USAGE" >&2
      echo "FILE_PATH, $FILE_PATH , is not a link." >&2
      exit 1
   fi
   ##echo "replace_link: At 1, DEST_PATH is $DEST_PATH"
   ##echo "replace_link: At 1, FILE_PATH is $FILE_PATH"
   ##echo "replace_link: At 2, DEST_PATH is $DEST_PATH"
   # If DEST_PATH starts with the directory of $FILE, then use a 
   # relative link
   FRONT="$(dirname "$FILE_PATH")/"
   eval "DEST_PATH=\"${DEST_PATH#${FRONT}}\""
   ##echo "replace_link: At 3, DEST_PATH is $DEST_PATH"
   echo "replace_link: Replace $FILE_PATH with $DEST_PATH"
   rm "$FILE_PATH"
   ln -s "$DEST_PATH" "$FILE_PATH"
   exit 0
