Change NGINX configuration root

#! /bin/sh

CONFIG_FILE="/etc/nginx/sites-available/project"
DIR=$1

if [ $# -eq 0 ]
  then
    DIR='.'
fi

DIR=$(readlink -f $DIR)
CONFIG=$(sed "s@root[^\n]*@root $DIR;@g" < $CONFIG_FILE)

$(echo "$CONFIG" > $CONFIG_FILE)
service nginx reload