Javascript/CSS packaing script

package.sh

#!/bin/bash

##
# Package multiple javascript/css files into a single file.
#
# This script will search a file for @PACKAGE-START and @PACKAGE-END annotations
# and merge all references files between those annotations into a single file.
# The first file in the list will be treated as the master file. References to
# the subsequent files will be removed.

BASEDIR=httpdocs
PACKAGE=0
root=""
file=$1

if [ -z $file ]; then
    echo "Must specify file to package"
    exit 1
fi

if [ ! -f $file ]; then
    echo "Unable to read $file"
    exit 1
fi

cnt=1

while read line
do

    echo $line | grep '@PACKAGE-END' > /dev/null
    if [ $? -eq 0 ]; then
        #echo "root is ${root}"
        root=""
        PACKAGE=0
    fi

    if [ $PACKAGE -eq 1 ]; then

        js=$(echo $line | sed -s 's#.* "\(.*\.js\).*#\1#g')
        js=$BASEDIR$js

        if [ -z $root ]; then
            root=$js
        else
            cat $js >> $root
            rm $js

            #echo "deleting line $cnt"
            sed -ie "${cnt}d" $file

            # decrement the line number since we just removed a line from the
            # file
            cnt=`expr $cnt - 1`
        fi
    fi

    echo $line | grep '@PACKAGE-START' > /dev/null
    if [ $? -eq 0 ]; then
        PACKAGE=1
    fi

    cnt=`expr $cnt + 1`

done < $file

This can be summed up with a little sed hacking:
sed -n -e ':x;/^@PACKAGE-START$/,/^@PACKAGE-END$/ p;tx' input_file | sed -e '/^@PACKAGE-(START|END)$/ d' > output_file