Adjust webserver group name to match your system! (_www is the default Apache httpd usergroup on OS X)

set-mage2-permissions.sh

#!/bin/bash

[ ! -d app ] && echo "Not in Magento 2 root directory" >&2 && exit 1

echo "Settting group ownership to _www"
chgrp -R _www .

echo "Setting directory base permissions to 0750"
find . -type d -exec chmod 0750 {} \;
echo "Setting file base permissions to 0640"
find . -type f -exec chmod 0640 {} \;

echo "Setting group write and sgid bit permissions for writable directories"
find var pub/media pub/static -type d -exec chmod g+ws {} \;
echo "Setting permissions for files in writable directories "
find var pub/media pub/static -type f -not -name .htaccess -exec chmod g+w {} \;

[ -e app/etc ] && echo "Making app/etc writable for installation"
[ -e app/etc ]  && chmod g+w app/etc

echo "Making vendor/bin scripts executable"
find -L vendor/bin -type f -exec chmod u+x {} \;

echo "Making bin/magento executable"
chmod u+x bin/magento

@Vinai

Looks like its deviated from the recommendation here in the below link

http://devdocs.magento.com/guides/v2.0/config-guide/prod/prod_file-sys-perms.html#mage-owner-two-devel

As per the above link the file permission should have 775. Can you please clarify.

When using the xargs approach, you can add the -n parameter to limit how many arguments are given to each invocation of the utility that xargs should run. e.g. find . -type d -print0 | xargs -0 -n10 chmod 0750 would run chmod with 10 directories at a time.