The DefineExternal(fn, extlib) command calls define_external with the MAPLE option and saves the result in a remember table.  The procedure used to prepare the invocation of the external routine fn is returned, optionally with the specified copyright statement cright.

Note: Saving the result of DefineExternal in a remember table is essential for the efficient operation of the external linking. Without it, the external communications must be set up every time an external routine is entered.

$\mathrm{with}\left(\mathrm{ExternalCalling}\right)\:$

$\mathrm{extlib}≔\mathrm{ExternalLibraryName}\left(''mstring''\right)$

$\mathrm{extlib}≔''libmstring.so''$

$\mathrm{extcall}≔\mathrm{DefineExternal}\left('\mathrm{mstring\_uppercase}'\,\mathrm{extlib}\right)$

$\mathrm{extcall}≔\mathbf{proc}\left(\right)\mathbf{option}\mathrm{call\_external}\,\mathrm{define\_external}\left(\mathrm{mstring\_uppercase}\,\mathrm{MAPLE}\,\mathrm{LIB}\=''libmstring.so''\right)\;\mathrm{call\_external}\left(0\,140327475850880\,\mathrm{true}\,\mathrm{false}\,\mathrm{false}\,\mathrm{args}\right)\mathbf{end\; proc}$

$\mathrm{extcall}≔\mathrm{DefineExternal}\left('\mathrm{mstring\_uppercase}'\,\mathrm{extlib}\,''Copyright\; (c)\; 2001,\; ...''\right)$

$\mathrm{extcall}≔\mathbf{proc}\left(\right)\mathbf{option}\mathrm{call\_external}\,\mathrm{define\_external}\left(\mathrm{mstring\_uppercase}\,\mathrm{MAPLE}\,\mathrm{LIB}\=''libmstring.so''\,\mathrm{COPYRIGHT}\=''Copyright\; (c)\; 2001,\; ...''\right)\,\mathrm{copyright}\=''Copyright\; (c)\; 2001,\; ...''\;\mathrm{call\_external}\left(0\,140327475850880\,\mathrm{true}\,\mathrm{false}\,\mathrm{false}\,\mathrm{args}\right)\mathbf{end\; proc}$