Unix find and replace text within all files within a directory

# *****************************************************************************************

# find_and_replace_in_files.sh
# This script does a recursive, case sensitive directory search and replace of files
# To make a case insensitive search replace, use the -i switch in the grep call
# uses a startdirectory parameter so that you can run it outside of specified directory - else this script will modify itself!
# *****************************************************************************************

!/bin/bash
# **************** Change Variables Here ************
startdirectory="/home/a133230/chklist"
searchterm="db_rman"
replaceterm="db_rman"
# **********************************************************

echo "******************************************"
echo "* Search and Replace in Files Version .1 *"
echo "******************************************"

        for file in $(grep -l -R $searchterm $startdirectory)
          do
           sed -e "s/$searchterm/$replaceterm/ig" $file > /tmp/tempfile.tmp
           mv /tmp/tempfile.tmp $file
           echo "Modified: " $file
        done

echo " *** Yay! All Done! *** "

by 

Jefferson Cândido Romeiro