cxxsubs

Basic C++ Subcommand/Verbs support for command line. It use cxxopts for each subcommand parsing.

The design was inspire by this C# library

Code is available on github cxxsubs

Design

Some interesting feature

• Completion script, you can add special cxxsubs::CompletionCommand which will add completion command for bash (cf. example.cpp)

Known limitations

• No Real Help message
• Subcommand can overlap (ex: ship new, ship). The ship new command will also execute ship command.

Quick start Example

1. Create separate option classes for each verb. Class have to work like IOptions.
2. Call cxxsubs::Verbs with all the verb options classes in template parameters.

C++ Class For New Verb:

class OptionsInit : public cxxsubs::IOptions {
public:
  OptionsInit()
      : cxxsubs::IOptions({"init"}, "Initialise repository") {
    // Create parser : add option group etc ...
    // cxxopts::Options is accessible with this->options
    this->options.add_options()
      ("m, module", "module name", cxxopts::value<std::string>()->default_value("my_module"))
      ("help", "Print help");
  }

  void validate() {
    // Validate parsing result : check help options, check rule between option (exclusivity etc ...)
    // cxxopts::Options is accessible with this->options
    // cxxopts::ParseResult is accessible with this->parse_result (warning it's a pointer)
    if (this->parse_result->count("help")) {
      std::cout << this->options.help({""}) << std::endl;
      exit(0);
    }
  }

  void exec() {
    // Execute what you want
    // cxxopts::Options is accessible with this->options
    // cxxopts::ParseResult is accessible with this->parse_result (warning it's a pointer)
    std::cout << "command : " << this->get_verbs() << std::endl;
    std::cout << "module : " << (*this->parse_result)["module"].as<std::string>() << std::endl;
  };
};

C++ Main:

int main(int argc, char *argv[]) {
  cxxsubs::Verbs<OptionsInit>(argc, argv);
}

Complete Example

A more complete example can be found in example.cpp file. The Example aim to produce the following command

naval_fate ship new <name>...
naval_fate ship shoot <x> <y>
naval_fate ship move <name> <x> <y>
naval_fate mine set <x> <y> [--moored|--drifting]
navel_fate mine remove <x> <y>

idea from the docopt library

Requirements

• cxxsubs depends on cxxopts.
• The only build requirement is a C++ compiler that supports C++14 regular expressions and some variadic template feature (std::index_sequence). For example GCC >= 5.5 works with c++14 options.

Documentation and examples generation

mkdir build
cd build
cmake ..
make
make docs

Example programs (example and quickstart) are located in build folder. The Documentaion will be generated in doc/html/index.html.