turbodt / cpp-commander

A tinny cpp library with CMAKE to create CLI commands.

Cpp Commander

The purpose of this library is to provide an easy way to handle CLI commands.

An example of use can be found here.

Integration

This library can be easy integrated using cmake:

include(FetchContent)

FetchContent_Declare(commander
  GIT_REPOSITORY https://github.com/turbodt/cpp-commander.git
  GIT_TAG main
)
FetchContent_MakeAvailable(commander)

[...]

add_executable(${PROJECT_NAME}
  ...
)

[...]

target_link_libraries(${PROJECT_NAME} PRIVATE Commander)

Usage

For more detailed usage, look at the example.

The library exposes a class Command from which your commands should extend. Is recommended to create an intermediate custom base command so all your commands can extend to. As example:

#include "cpp-commander.h"

class BaseCommand : public Commander::Command {
public:
  using Commander::Command::Command;

  void initialize() {
    this->add("-h, --help", "Shows help.");
  }

protected:

  int execute_wrapper(Commander::ArgumentList *list) const {
    if (this->get_option("--help")->has_appeared()) {
      std::cout << this->get_help() << std::endl;
      return 0;
    }
    return this->Command::execute_wrapper(list);
  }
};

Basic command

To create a basic command, just extend from Commander::Command (or, as mentioned previously, from BaseCommand):

class SimpleCommand : public BaseCommand {
public:
  using BaseCommand::BaseCommand;

  void initialize() {
    this->BaseCommand::initialize();
    this->set_description("This the definition of the command.")
        ->add("-m, --message <message>", "This is an option.")
        ->add("--debug", "This is an option without parameter.")
        ->add("<file>", "This is a mandatory positional argument.")
        ->add("[size]", "This is an optional argument."
                        " Should be added after all mandatory arguments.");
  }

  int execute() const {
    auto file = this->get_positional("file")->get_value();
    auto also_file = this->get_positional(0)->get_value();

    auto size = "xl";
    if (this->get_positional("size")->has_value()) {
      size = this->get_positional("size")->get_value();
    }

    if (this->get_option("--message")->has_appeared()) {
      auto message = this->get_option("--message")->get_value();
      // Do whatever
    }

    // Do whatever
    return 0;
  };
};

Composed command

Also is posible to group several subcommands into a command:

class MainCommand : public BaseCommand {
public:
  using BaseCommand::BaseCommand;

  void initialize() {
    this->set_description("This is a command composed of several subcommands.")
        ->add("-l,--location <location>", "An example parameter")
        ->add_subcommand("subcommand1", new SubCommand1());
        ->add_subcommand("subcommand2", new SubCommand2());
  }
};

Execute the commands

Previous subsections explained how to actually define the commands. The way of run the commands is:

int main(int argc, char *argv[]) {
  auto command = MainCommand();
  return command.from_main(argc, argv);
}

or

command.from_line("myprogram -h");

Other

I'm not an expert on C++, so please if you have any suggestion of improvement or find any pattern that can suppose a problem on common integrations, please open an issue and we'll try to improve the code. Thanks.