PHP Syntax check before pre-commit hook of git

pre-commit.sh

#!/bin/sh
PHP="/usr/bin/php"
PWD=`pwd`
SYNTAXCHECK="/usr/bin/php -l"

GIT_ROOT=`pwd`/`git rev-parse --show-cdup`
MODIFIED_FILES=`git diff-index --cached HEAD | awk '{print $6}'`

ERRORS=""
for f in $MODIFIED_FILES;do
  FNAME=${GIT_ROOT}${f}
  if [ "php" != "${FNAME##*.}" ];then
    continue
  fi
  RESULT=`$SYNTAXCHECK $FNAME`
  if [ "$?" != "0" ];then
    ERRORS="$ERRORS\n\n$RESULT"
  fi
done

if [ -n "$ERRORS" ];then
    echo "$ERRORS"
    exit 1
else
    exit 0
fi