There is a command called patch that apply a diff file or patch to an original source tree.
patch takes a patch file patchfile containing a difference listing produced by the diff program and applies those differences to one or more original files, producing patched versions. Normally the patched versions are put in place of the originals.
The following usage is most commonly used:
$ patch -p1 < {/path/to/patch/file}
To apply a patch, one could run the following command in a shell:
$ patch < /path/to/file
Patches can be undone, or reversed, with the '-R' option:
$ patch -R < /path/to/file
Above 3 are basic usage read the man page of patch command for more information and usage:
% man patch
