.. index:: plugin

plugin command
==============

Syntax
""""""

.. code-block:: LAMMPS

   plugin command args

* command = *load* or *unload* or *list* or *clear*
* args = list of arguments for a particular plugin command

  .. parsed-literal::

     *load* file = load plugin(s) from shared object in *file*
     *unload* style name = unload plugin *name* of style *style*
         *style* = *pair* or *bond* or *angle* or *dihedral* or *improper* or *kspace* or *compute* or *fix* or *region* or *command*
     *list* = print a list of currently loaded plugins
     *clear* = unload all currently loaded plugins

Examples
""""""""

.. code-block:: LAMMPS

   plugin load morse2plugin.so
   plugin unload pair morse2/omp
   plugin unload command hello
   plugin list
   plugin clear

Description
"""""""""""

The plugin command allows to load (and unload) additional styles and
commands into a LAMMPS binary from so-called dynamic shared object (DSO)
files.  This enables to add new functionality to an existing LAMMPS
binary without having to recompile and link the entire executable.

The *load* command will load and initialize all plugins contained in the
plugin DSO with the given filename.  A message with information the
plugin style and name and more will be printed.  Individual DSO files
may contain multiple plugins.  More details about how to write and
compile the plugin DSO is given in programmer's guide part of the manual
under :doc:`Developer_plugins`.

The *unload* command will remove the given style or the given name from
the list of available styles.  If the plugin style is currently in use,
that style instance will be deleted.

The *list* command will print a list of the loaded plugins and their
styles and names.

The *clear* command will unload all currently loaded plugins.

.. admonition:: Automatic loading of plugins
   :class: note

   .. versionadded:: 4May2022

   When the environment variable ``LAMMPS_PLUGIN_PATH`` is set, then
   LAMMPS will search the directory (or directories) listed in this path
   for files with names that end in ``plugin.so``
   (e.g. ``helloplugin.so``) and will try to load the contained plugins
   automatically at start-up.


Restrictions
""""""""""""

The *plugin* command is part of the PLUGIN package.  It is
only enabled if LAMMPS was built with that package.  See
the :doc:`Build package <Build_package>` page for more info.

If plugins access functions or classes from a package,
LAMMPS must have been compiled with that package included.

Plugins are dependent on the LAMMPS binary interface (ABI)
and particularly the MPI library used. So they are not guaranteed
to work when the plugin was compiled with a different MPI library
or different compilation settings or a different LAMMPS version.
There are no checks, so if there is a mismatch the plugin object
will either not load or data corruption and crashes may happen.


Related commands
""""""""""""""""

none


Default
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none
