Update Drupal 7 core files without drush

update_drupal_core.sh

#!/bin/bash
# Update Drupal core for an existing Drupal 7 installation.
# Change directory to the web root and run this through there.
# No root rights needed.
#
# From the update, 'sites' folder and '.htaccess' file are excluded.
#
# WARNING: There might be security updates to the .htacess file. Make sure that
# the security updates are merged in.

root_dir=`pwd`
tmp_dir=`mktemp -d`

if [ ! -d "$tmp_dir" ]; then
	echo "There was a problem creating a temporary directory. Exiting."
	exit 1;
fi
echo "Drupal directory: $root_dir"
echo "Temporary directory: $tmp_dir"

# Download the latest drupal version.
read -p "You are about to dowload the latest Drupal and update core. Proceed? " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
	cd $tmp_dir
	echo "Downloading the latest version of drupal 7"
	wget $(wget -O- -q https://updates.drupal.org/release-history/drupal/7.x | grep -oPm1 "(?<=<download_link>)[^<]+") -O latest_drupal.tar.gz
	mkdir latest_drupal

	echo "Extracting..."
	tar -xzf latest_drupal.tar.gz --strip 1 -C latest_drupal
else
	echo "Abording..."
	rm -rf $tmp_dir
	exit -1
fi

# Perform the update.
read -p "WARNING: You are about to update Drupal core. All files except sites folder and .htaccess will be overriden. Proceed? " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
	echo "Updating core..."
	rsync -cazr --exclude="sites" --exclude=".htaccess" latest_drupal/ $root_dir
else
	echo "Abording..."
	rm -rf $tmp_dir
	exit -1
fi

# When the rsync completes, the permission of the web root directory changes to 0775.
# This impacts some hosting services which raise a fatal error when the directory is
# writable by group (e.g. cPanel). Fix permissions.
echo "Changing web root directory permissions to 0755."
chmod 0755 $root_dir

# Clean up.
echo "Update complete. Please update the database. Removing $tmp_dir"
rm -rf $tmp_dir