git hooks pre-commit to automatic update *.js *.css version

pre-commit

#!/bin/bash
###
## change js and css file version by append ?v111111
##
## usage: copy to .git/hooks/pre-commit
## chmod a+x .git/hooks/pre-commit
#
##

modified_files=$(git diff --cached --name-only)
#echo $modified_files
for f in $modified_files
do
    #echo $f
    ext="${f##*.}"
    fname=`basename $f`
    if [ -e "$f" ] && ([[ $ext == css ]] || [[ $ext == js ]] ); then
        include_files=`grep src -r -e "$fname" |awk -F: '{print $1}' |uniq`
        for f2 in $include_files
        do
          ver=`stat -c %Y $f2`
          sed -i "s/$fname.*\"/$fname\?v$ver\"/g" $f2
          git add $f2
        done

        git add $f
    fi
done