This shell script will copy all file and directories recursively but not overwrite anything unless specified

treeclone.sh

#!/bin/sh
# treeclone - pretty much just a wrapper around cp but only for cloning the 
# CONTENTS of a directory (via /. ) recursively (-a) and non-destructive (-n) 
# by default. Useful for preventing disaster from forgetting -n

if   [ "$#" -eq 1 ]; then TO=$CALLER
elif [ "$#" -lt 4 ]; then TO=$2
else
  echo "incorrect number of args: treeclone takes at 1 - 3 args"
  echo "This will copy all file and directories recursively but not overwrite anything:"
  echo "  $ treeclone <from-dir> <to-dir>"
  echo "this will overwrite:"
  echo "  $ treeclone <from-dir> <to-dir> -f"
  echo "Both paths can be relative and if there is only one argument, it defines"
  echo "the source with the desination assumed to be the current directory."
  exit 1
fi

if [ "$3" == "-f" ]; then
  cp -a $1/. $TO/
else 
  cp -an $1/. $TO/
fi

z_treeclone-old.sh

#!/bin/sh
# treeclone
# THIS VERSION HAS TWO ISSUES: 
# 1. It does not copy file at root of source. 2. It does not copy hidden items anywhere.

if   [ "$#" -eq 1 ]; then TO=$(pwd)
elif [ "$#" -lt 4 ]; then TO=`cd "$2"; pwd`
else
  echo "incorrect number of args: treeclone takes at 1 - 3 args"
  echo "This will copy all file and directories recursively but not overwrite anything:"
  echo "  $ treeclone <from-dir> <to-dir>"
  echo "this will overwrite:"
  echo "  $ treeclone <from-dir> <to-dir> -f"
  echo "Both paths can be relative and if there is only one argument, it defines"
  echo "the source with the desination assumed to be the current directory."
  exit 1
fi

if [ "$3" == "-f" ]
 then FORCE=true
else  FORCE=false
fi

FROM=`cd "$1"; pwd`

cd $FROM
for dir in */
do
  dir=${dir%*/}
  dir=${dir##*/}
  echo $dir

  if $FORCE
   then cp -R $FROM/$dir $TO
  else cp -Rn $FROM/$dir $TO
  fi
done