#!/bin/sh -
#
# merge -- Non-destructive Move (Copy) files
#
# Usage: merge [-c] from to
#        merge [-c] files... dir
# Options: -c  copy instead of move the files
#
#   This is equivelant to a `mv' operation except that files which would
# overwrite an existing file (IE: file is destination directory has the
# same name as a file being moved) will be renamed by appending a number
# to it.  The user is given a message when such renaming occurs, so
# appropiate action can be taken.  This is so that no file is destroyed
# by a normal `mv' command especially when merging two directories of
# filenames.
#   The `-c' flag will make this script use `cp' instead of `mv'.
#
# Author:    Anthony Thyssen  <anthony@cit.gu.edu.au>
#
# Check the type of shell that is running (For ULTRIX systems)
[ "X$1" != 'X-sh5' -a -f /bin/sh5 ] && exec /bin/sh5 -$- "$0" -sh5 "$@"
[ "X$1" = 'X-sh5' ] && shift

sep='
'     # field seperator for internal filename list ( ':' when debuging )
attach='.'   # string put between original name and appended number (dups)
cmd="mv"

doit() {
  # move/copy the file $1 to directory $2 as filename $3
  n=1         # index for multiple items
  f="$3"      # destination filename to try
  while [ -f "$2/$f" -o -d "$2/$f" ]; do
    n=`expr $n + 1`
    f="$3$attach$n"
  done
  [ $n -gt 1 ] && echo "file \"$3\" exists -> renamed \"$f\""
  $cmd "$1" "$2/$f"
}

usage() {
  echo "Usage: merge [-c] from to" >&2
  echo "       merge [-c] files... dir" >&2
  echo "Options: -c  copy instead of move the files" >&2
  echo "" >&2
  exit 10
}

case "$1" in
-c) cmd="cp"; shift ;;
esac

case $# in
 0|1)
  echo "merge: Too few arguments!" >&2
  usage
  ;;
 2) # handle direct filename to filename when arg 2 is not a directory
   if [ ! -d "$2" ]; then
     case $2 in
       /*) # Gad! -- a absolute filename given just move it
           doit "$1" "" "$2" ;;
       *)  # ok just a relative filename move it to directory `.'
           doit "$1" "." "$2" ;;
     esac
     exit 0
   fi
   ;;
esac


files="$1"; shift   # first arg must be a filename to move/copy
dir="$1"; shift     # assume arg 2 is destination (sort it out below)

while [ $# -gt 0 ]; do
  files="$files$sep$dir"  # append the non-destination to file list
  dir="$1"                # assume this is the destionation
  shift
done

# debugging -- check what is read in (change $sep above for testing)
# echo "dir=$dir"
# echo "files=$files"

if [ ! -d "$dir" ]; then
  echo "merge: multiple files given, but destination is not a directory" >&2
  usage
fi

oldIFS=$IFS; IFS=$sep; set -- $files; IFS=$oldIFS

# For each file in list (no that we have a destination) move/copy it
for i in "$@"; do
  doit "$i" "$dir" "`basename $i`"
done