Hi all! I'm using parse_config_file to read my options from a file. Some of them are only a flag (ie no value given), like -z (--gzip), -h (--help) or -v (--verbose). What I see is that those options can be specified with the file only if some dummy value is given. For concreteness, let's say that the option is gzip. If I put gzip= the result is "Error: no value given in 'gzip='". If the = isn't put, then the message is "Error: unrecognized line in 'gzip'". Using spaces doesn't help because they are trimmed away. The method common_config_file_iterator::get() (config_file.cpp) seems to be involved: else if ((n = s.find('=')) != string::npos) { string name = m_prefix + trim_ws(s.substr(0, n)); string value = trim_ws(s.substr(n+1)); if (!allowed_option(name)) boost::throw_exception(unknown_option(name)); //// Doesn't allow empty values for an option. if (value.empty()) boost::throw_exception(invalid_syntax(s, "no value given")); found = true; this->value().string_key = name; this->value().value.clear(); this->value().value.push_back(value); break; } else { boost::throw_exception(invalid_syntax(s, "unrecognized line")); } The trimming may be handy, but it seems useful to allow empty values; on the other hand, it seems that whether an empty value is legal or not should be checked on a higher level. Thanks a lot. -- Rodolfo Federico Gamarra