# 2.7. Applying patches

It is easy to stay current with the most recent LAMMPS patch releases if you use Git or SVN to track LAMMPS development. Instructions for how to stay current are on the Install git and Install svn doc pages.

Note

You should not apply patch files to a local Git or SVN repo of LAMMPS, only to an unpacked tarball. Use Git and SVN commands to update repo versions of LAMMPS.

Here are the steps to apply a patch file. Note that if your version of LAMMPS is several patch releases behind, you need to apply all the intervening patch files in succession to bring your version of LAMMPS up to date.

• Put the patch file in your top-level LAMMPS directory, where the LICENSE and README files are.

• Apply the patch by typing the following command from your top-level LAMMPS directory, where the redirected file is the name of the patch file.

patch -bp1 < patch.12Dec16

• A list of updated files print out to the screen. The -b switch creates backup files of your originals (e.g. src/force.cpp.orig), so you can manually undo the patch if something goes wrong.

• Type the following from the src directory, to enforce consistency between the src and package directories. This is OK to do even if you don’t use one or more packages. If you are applying several patches successively, you only need to type this once at the end. The purge command removes deprecated src files if any were removed by the patch from package sub-directories.

make purge
make package-update

• Re-build LAMMPS via the “make” command.

Warning

If you wish to edit/change a src file that is from a package, you should edit the version of the file inside the package sub-dir of src, then re-install the package. The version in the src dir is merely a copy and will be wiped out if you type “make package-update”.