How to Parse Command Line Arguments in C++? [dupli

Question

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What parameter parser libraries are there for C++?

What is the best way of parsing command-line arguments in C++ if the program is specified to be run like this:

prog [-abc] [input [output]]

Is there a library in STL to do this?

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Related:

• Parsing command line arguments in a unicode C++ application

Answer 1

Quite a late answer, but I have used GetPot for some projects: http://getpot.sourceforge.net/

Main feature: everything is in a single header file, no build hassles. Just save it somewhere on your machine and "#include" it in your file holding main()

Hasn't be updated recently, but nicely documentated, and works well. You can give it a try.

Answer 2

I can suggest Templatized C++ Command Line Parser Library (some forks on GitHub are available), the API is very straightforward and (cited from the site):

the library is implemented entirely in header files making it easy to use and distribute with other software. It is licensed under the MIT License for worry free distribution.

This is an example from the manual, colored here for simplicity:

#include <string>
#include <iostream>
#include <algorithm>
#include <tclap/CmdLine.h>

int main(int argc, char** argv)
{

    // Wrap everything in a try block.  Do this every time,
    // because exceptions will be thrown for problems.
    try {

    // Define the command line object, and insert a message
    // that describes the program. The "Command description message"
    // is printed last in the help text. The second argument is the
    // delimiter (usually space) and the last one is the version number.
    // The CmdLine object parses the argv array based on the Arg objects
    // that it contains.
    TCLAP::CmdLine cmd("Command description message", ' ', "0.9");

    // Define a value argument and add it to the command line.
    // A value arg defines a flag and a type of value that it expects,
    // such as "-n Bishop".
    TCLAP::ValueArg<std::string> nameArg("n","name","Name to print",true,"homer","string");

    // Add the argument nameArg to the CmdLine object. The CmdLine object
    // uses this Arg to parse the command line.
    cmd.add( nameArg );

    // Define a switch and add it to the command line.
    // A switch arg is a boolean argument and only defines a flag that
    // indicates true or false.  In this example the SwitchArg adds itself
    // to the CmdLine object as part of the constructor.  This eliminates
    // the need to call the cmd.add() method.  All args have support in
    // their constructors to add themselves directly to the CmdLine object.
    // It doesn't matter which idiom you choose, they accomplish the same thing.
    TCLAP::SwitchArg reverseSwitch("r","reverse","Print name backwards", cmd, false);

    // Parse the argv array.
    cmd.parse( argc, argv );

    // Get the value parsed by each arg.
    std::string name = nameArg.getValue();
    bool reverseName = reverseSwitch.getValue();

    // Do what you intend.
    if ( reverseName )
    {
            std::reverse(name.begin(),name.end());
            std::cout << "My name (spelled backwards) is: " << name << std::endl;
    }
    else
            std::cout << "My name is: " << name << std::endl;


    } catch (TCLAP::ArgException &e)  // catch any exceptions
    { std::cerr << "error: " << e.error() << " for arg " << e.argId() << std::endl; }
}

Answer 3

I'd recommend boost::program_options if you can use the Boost lib.

There's nothing specific in STL nor in the regular C++/C runtime libs.

Answer 4

AnyOption is a C++ class for easy parsing of complex commandline options. It also parses options from a rsourcefile in option value pair format.

AnyOption implements the traditional POSIX style character options ( -n ) as well as the newer GNU style long options ( --name ). Or you can use a simpler long option version ( -name ) by asking to ignore the POSIX style options.