Create and Apply a Patch to a Drupal Module

From a terminal...

Patching a Single File

Navigate to your module's directory that contains the changes you have made:

cd /var/www/my-website/sites/all/modules/custom/my_module

Create the patch file by running a diff on your OTHER module file and comparing it to your updated module file:

diff -ruN /var/www/my-OTHER-website/sites/all/modules/custom/my_module/my_module.module my_module.module > my_module.module.patch

Copy the patch file to the same directory as the file that needs to be patched:

cp my_module.module.patch /var/www/my-OTHER-website/sites/all/modules/custom/my_module

Navigate to the the directory where you just copied the patch file:

cd /var/www/my-OTHER-website/sites/all/modules/custom/my_module

Apply the patch and create a backup of the original:

patch -b my_module.module my_module.module.patch

If the patch is applied successfully and all looks well, you can remove both .patch files and .orig file:

rm my_module.module.patch
rm my_module.orig
rm /var/www/my-website/sites/all/modules/custom/my_module/my_module.module.patch

Patching a Multiple Files in a Directory

# go to home directory, e.g. /home/tyler
cd ~

# create the patch file
diff -ruN /home/tyler/original_directory/ /home/tyler/updated_directory/ > tyler.patch

# apply the patch
patch -p0 -i tyler.patch

Now venture forth to create and apply patches to save us from praise the robots, thanks.