Command

C++ library for handling command line arguments.

Installation

debian package

$ wget https://github.com/quayle/command/releases/download/v0.3-deb/command_0.3_all.deb
$ sudo dpkg -i command_0.3_all.deb

from sources

You will need to have autotools installed (automake, autoconf, ...)

$ ./autogen.sh
$ ./configure
$ make
$ sudo make install

Configuration

You need to enable c++11 support in your compiler. You can achieve that in g++ and clang++ by adding -std=c++11 compilation flag.

As this is header-only library, you don't need any additional steps.

Usage

example.cpp:

#include <iostream>
#include <string>
#include <command/command.h>
#include <command/option.h>
#include <command/argument.h>

using namespace command;

class MyClass {
    std::string _value = "Default";
public:
    void setValue(std::string value) {
        this->_value = value;
    }
    std::string getValue() {
        return std::string("Value from MyClass: ") + this->_value;
    }
};

int main(int argc, char *argv[]) {
    MyClass myClass;
    try {
        Command command(argc, argv, {
            new Option<void>("-h", "Help", [](void) {
                std::cout << "Help information\n";
            }),
            new Argument<std::string>("Value for MyClass",
                std::bind(&MyClass::setValue, &myClass, std::placeholders::_1)
            )
        });
    }
    catch(const std::exception & e) {
        return 1;
    }

    std::cout << myClass.getValue() << std::endl;

    return 0;
}

Now program can be compiled & run using following commands:

$ g++ -std=c++11 example.cpp
$ ./a.out -h
Help information
Value from MyClass: Default

$ ./a.out someArg
Value from MyClass: someArg

$ ./a.out someArg -h
Help information
Value from MyClass: someArg

Possible classes to use:

Arguments are non-named program parameters. They must have some description and function handling when argument is passed:

new Argument<bool>("Bool argument", [](bool value) { });

Options are named program parameters. Option need name (e.g.: "i"), description, and function.

new Option<int>("name", "Integer option", [](int value) { });

Options could also be set as containing no value. In that case they become just a simple switches (some kind of mix between Argument and Option). They are used just to invoke some function if specific name was passed:

new Option<void>("v", "Verbose mode of program", [](void) { });

Behaviours

Parameters (Options and Arguments) can also be wrapped in Behaviours.

Required behaviour - if specific parameter was not passed and is required, exception is thrown (missingRequiredParameter):

new Required(
    new Argument<bool>("Bool argument", [](bool value) { })
);

MultiValue behaviour - given parameter can handle more than one value. Values are separated by given separator. For each value passed function is invoked:

new MultiValue(",",
    new Option<std::string>("input", "Input file", [](std::string value) { })
)

More complex example:

(...)
void argument_function(bool a) {
    std::cout << "Argument: " << a << std::endl;
}

void option_function(std::string a) {
    std::cout << "Option function " << a << std::endl;
}

void void_function(void) {
    std::cout << "Void function " << std::endl;
}

Command command(argc, argv, {
    new Required(
        new MultiValue("-",
            new Argument<bool>("Input values", argument_function)
        )
    ),
    new MultiValue(",",
        new Option<std::string>("f", "Optional file", option_function)
    )
    new Option<void>("h", "Help", void_function)
});
(...)

Above code allows us to:

Parameters wrapped in Required class, have validator which checks if argument is passed:

$ ./a.out
*Input values* is required

$ ./a.out 1
Argument: 1

$ ./a.out 0
Argument: 0

$ ./command 0 f
Option: f requires value to be specified after equal sign, but no equal sign was found

$ ./command 0 f=
Option: f failed value conversion to the required type

For MultiValue Parameters each value is passed to the given function:

$ ./a.out 1-0-1
Argument: 1
Argument: 0
Argument: 1

$ ./command 0 f=one,two,three
Argument: 0
Option function one
Option function two
Option function three

Documentation

Current documentation can be found at: http://dlugolecki.net.pl/software/command/docs/

If for some reason it is unavailable, you can build it yourself. The only requirement is to have Doxygen installed when make command is invoked.