2 examples for patch

  # Applies the .patch file path/file.patch to the current directory.
#
# Note: The p1 flag is for compatibility with patches created with git, and stands
# for the number of leading prefixes to strip. If that doesn't work, try using
# just p0.
#
# See https://drupal.org/patch/apply for some more detailed information.
patch -p1 < path/file.patch
        

  # Reverts a previously applied patch
#
# p1 flag is used by git. If your diff is in a 
# different format try using p0 
patch -R -p1 < patch/file.diff