luaL_register

void luaL_register (lua_State *L,
                    const char *libname,
                    const luaL_Reg *l);

Opens a library.

When called with libname equal to NULL, it simply registers all functions in the list l (see luaL_Reg) into the table on the top of the stack.

When called with a non-null libname, creates a new table t, sets it as the value of the global variable libname, sets it as the value of package.loaded[libname], and registers on it all functions in the list l. If there is a table in package.loaded[libname] or in variable libname, reuses this table instead of creating a new one.

In any case the function leaves the table on the top of the stack.