sillydan1/argvparse

A tiny C++ library for easier parsing of command line arguments

argvparse

A C++ library for easier parsing of command line arguments

Example Usage

Using argvparse is easy. You just define a list of desired arguments with a description and then you call auto myargs = get_arguments(possible_arguments, argc, argv);. You can then check if an argument has been provided by looking up the results like so: myargs["long-name-look-up"]. The result from get_arguments is a hashmap where the long name of the argument is the key.

Longer example. This example is also available as a build target: make example_usage

#include <iostream>
#include "arguments.h"

int main(int argc, char** argv) {
    // Construct your cli flag options as a vector of option_t's
    // The --help flag gets added automatically
    std::vector<option_t> my_options = {
    //   long name   |short| argument requirement             | Help description
        {"flag"      , 'a', argument_requirement::NO_ARG      , "Flag"},
        {"input-file", 'f', argument_requirement::REQUIRE_ARG , "Argument"},
        {"input-files",'F', argument_requirement::REQUIRE_ARG , "Argument that can be set multiple times (-F a -F b)"},
        {"optimize"  , 'o', argument_requirement::OPTIONAL_ARG, "Flag or Argument"}
    };
    // Then call get_arguments
    auto cli_arguments = get_arguments(my_options, argc, argv);
    // If the help flag was provided, print out the help message
    if(cli_arguments["help"]) {
        std::cout << "Copyright (C) 2020  Asger Gitz-Johansen\n"
                     "\n"
                     "    This program is free software: you can redistribute it and/or modify\n"
                     "    it under the terms of the GNU General Public License as published by\n"
                     "    the Free Software Foundation, either version 3 of the License, or\n"
                     "    (at your option) any later version.\n"
                     "\n"
                     "    This program is distributed in the hope that it will be useful,\n"
                     "    but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
                     "    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n"
                     "    GNU General Public License for more details.\n"
                     "\n"
                     "    You should have received a copy of the GNU General Public License\n"
                     "    along with this program.  If not, see <https://www.gnu.org/licenses/>.\n"
                     "================================================================================\n"
                     "This is a program that shows how to use libargvparse. Below are the possible options\n\n"
                  << my_options;
        return EXIT_SUCCESS;
    }
    // You can test if an argument was provided by simply testing for the long name
    if(cli_arguments["flag"])
        std::string flag_file = cli_arguments["flag"].as_string(); // Throws a runtime_exception, since there are no arguments on '--flag'

    if(cli_arguments["input-file"])
        std::cout << cli_arguments["input-file"].as_string() << std::endl;

    if(cli_arguments["input-files"]) {
        for(auto& el : cli_arguments["input-files"].as_list())
            std::cout << el << " ";
        std::cout << std::endl;
    }

    if(cli_arguments["optimize"])
        std::string optimize_strategy = cli_arguments["optimize"].as_string(); // Throws a runtime_exception if no flag was provided

    // If you don't want to have the pesky if-statement, there's a variant of as_X:
    // Throws a runtime_exception if flag was provided, but no value. If the flag is not provided, then default value is returned.
    auto my_value = cli_arguments["input-file"].as_string_or_default("default_file_name.txt");
    std::cout << my_value << std::endl;
    return EXIT_SUCCESS;
}

Install

For compiling this library, a C++17 compatible compiler is required. The library also uses standard library components, so if you don't like that feel free to submit a pull request with custom 'unordered_map', 'vector' and 'std::for_each' implementations.

mkdir bin && cd bin
cmake .. -DCMAKE_BUILD_TYPE=Release 
sudo make install

For uninstall

xargs rm < install_manifest.txt

Or just manually delete the files listed in install_manifest.txt. They are likely these:

/usr/local/lib/libargvparse.so
/usr/local/include/arguments.h

Author

• sillydan1