Shell Script for grep-based search and replace recursively in files

grepReplace

#!/bin/sh
SEARCH=$1
REPLACE=$2

function ConfirmOrExit() {
   echo -n "Continue? (y / n) :"
   read CONFIRM
   if [ $CONFIRM != 'y' ]
   then
      exit
   fi
}

if [ -z "$SEARCH" -o -z "$REPLACE" ]; then
   echo "Searches for a specified string in the current directory and replaces all occurrences with the given replacement"
   echo "Examples:"
   echo "   grepReplace great greater"
   echo "   grepReplace \"the best\" \"the worst\""
   echo
   echo "Note: both arguments are required to be non-empty"
   exit
fi
GREP_EXCLUDE="grep -vE \.svn|\.git"

echo "Show potential results of searching for \"$SEARCH\" and replacing with \"$REPLACE\" in the current directory.";
ConfirmOrExit

echo
echo 'Before Replacement ############################################'
echo
grep --color -sF "$SEARCH" -r . | $GREP_EXCLUDE | grep --color -F "$SEARCH"

echo 
echo 'After Replacement #############################################'
echo
grep -sF $GREP_OPT "$SEARCH" -r . | $GREP_EXCLUDE | sed "s/$SEARCH/$REPLACE/" | grep --color -F "$REPLACE"

echo 
echo 'Perform the search and replace?'
ConfirmOrExit
grep -shlF "$SEARCH" -r . | $GREP_EXCLUDE | xargs sed "s/$SEARCH/$REPLACE/" -i