nvim/lua/lsp/c.lua

return {
  on_attach = function()
    G.api.nvim_create_user_command('R', function()
      G.cmd [[set splitbelow]]
      G.cmd [[sp]]
      G.cmd [[term g++ "%" -o "%<" && ./"%<" && rm "%<"]]
      G.cmd [[startinsert]]
    end, {})
  end
}