Oracle cli client (sqlplus) has a neat feature, if you put `/[enter]` in the prompt, it re-executes the last SQL.

```sql
:) select 1;
┌─1─┐
│ 1 │
└───┘

:) /
┌─1─┐
│ 1 │
└───┘
```

currently `<up><enter>` pollutes the screen by the SQL text and can contain SQL script, not a single query. Probably echo should be disabled in this case as well.
{
    if (allow_repeated_settings)
        cmd_settings.addProgramOptionsAsMultitokens(options_description.main_description.value());
    else
        cmd_settings.addProgramOptions(options_description.main_description.value());
    /// Parse main commandline options.
    auto rguments).options(options_description.main_description.value()).allow_unregistered();
    po::parsed_options parsed = parser.run();
    /// Check unrecognized options without positional options.
    auto unrecognized_options = po::collect_unrecognized(parsed.options, po::collect_unrecognized_mode::exclude_positional);
    if (!unrecognized_options.empty())
    {
        auto hints = this->getHints(unrecognized_options[0]);
        if (!hints.empty())
            throw Exception(ErrorCodes::UNRECOGNIZED_ARGUMENTS, "Unrecognized option '{}'. Maybe you meant {}", unrecognized_options[0], toString(hints));
        throw Exception(ErrorCodes::UNRECOGNIZED_ARGUMENTS, "Unrecognized option '{}'", unrecognized_options[0]);
    }
    /// Check positional options (options after ' -- ', ex: clickhouse-client -- <options>).
    unrecognized_options = po::collect_unrecognized(parsed.options, po::collect_unrecognized_mode::include_positional);
    if (unrecognized_options.size() > 1)
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Positional options are not supported.");
    po::store(parsed, options);
}
void ClientBase::init(int argc, char ** argv)
{
    namespace po = boost::program_options;
    /// Don't parse options with Poco library, we prefer neat boost::program_options.
    stopOptionsProcessing();
    stdin_is_a_tty = isatty(STDIN_FILENO);
    stdout_is_a_tty = isatty(STDOUT_FILENO);