clipper

Table of contents

• About
• Quick Start
  • Get clipper
  • Usage
  • Example
• Details
  • clipper
  • flags
  • options
• License

About

Clipper is a simple, header-only library that handles commad line arguments and parsing.

It is a learning project, that I took on to improve my C++ 📈.

Quick Start

Get clipper

Firstly download the library and include clipper.hpp in your .cpp file. Now just use it!

Usage

To begin you need to create an instance of CLI::clipper class.

CLI:clipper

Then you can add flags and options.
set() gives the variable that an option is going to save the value to (for options you have to give the name of the parameter that it is setting).

cli.add_flag("--verbose", "-v")
    .set(f)
    .doc("Displays verbose information");

cli.add_option<std::string>("--input", "-i")
    .set("file", i)
    .doc("Input file")
    .req();

You use the match() function to give viable values for an option. Alse with the set() function you can set the default value of the option.

cli.add_option<std::string>("--encoding", "-e")
    .set("charset", i, "utf8")  // utf8 is the default
    .match("utf8", "utf16", "cp1252", "latin1")
    .doc("Sets the encoding");

To parse arguments just use parse().

cli.parse(argc, argv);

Furthermore it is possible to add some information about the program.

CLI::clipper cli;
cli
  .name("foo")
  .version("1.0.0")
  .author("me")
  .description("app that does things")
  .license("GPLv3")
  .web_link("https://github.com/pawelrapacz");

To display help or version info you can do this:

std::cout << cli.make_help();
std::cout << cli.make_version_info();

clipper class gives access to the wrong member which is a const std::vector<std::string>& and contains any parsing errors like:

• Unkonown argument
• Missing required argument
• Missing option value
• Value is not allowed

std::cout << cli.wrong.front();

Example

#include "clipper.hpp"
#include <iostream>

int main(int argc, char** argv) {
    CLI::clipper cli("app", "1.0.0", "", "LGPLv3");

    bool show_help, show_version, flag;
    std::string input_file;
    int count;

    cli.help_flag("--help", "-h").set(show_help);
    cli.version_flag("--version", "-v").set(show_version);

    cli.add_flag("--flag", "-f")
        .set(flag)
        .doc("Sets Flag");

    cli.add_option<std::string>("--input", "-i")
        .set("file", input_file)
        .doc("Input file")
        .req();

    cli.add_option<int>("--count")
        .doc("Sets count")
        .set("number", count, 13)
        .match(1, 2, 3, 13, 14);
        

    if (not (cli.parse(argc, argv) or cli.wrong.empty())) {
        for (auto& i: cli.wrong)
            std::cout << i << "\n";
        return 1;
    }

    if (show_help) {
        std::cout << cli.make_help();
    }

    if (show_version) {
        std::cout << cli.make_version_info();
    }

    return 0;
}

Details

clipper class

This class is practically the only interface of the clipper library, that is meant to be directly used. It holds the neccessary and optional information about the application, options and flags.

Member	Description	Return value
clipper()	constructor
clipper(app_name)	constructor
clipper(app_name, version, author, license_notice)	constructor
~clipper()	destructor
name(name)	sets the name	clipper&
name()	gets the name	const std::string&
description(description)	sets the description	clipper&
description()	gets the description	const std::string&
version(version)	sets the version	clipper&
version()	gets the version	const std::string&
author(author)	sets the author	clipper&
author()	gets the author	const std::string&
license(license_notice)	sets the license notice	clipper&
license()	gets the license notice	const std::string&
web_link(web_link)	sets the web link	clipper&
web_link()	gets the web link	const std::string&
add_option<type>(name)	adds a option of a given type	option&
add_option<type>(name, alt_name)	adds a option of a given type with an alternative name	option&
add_flag(name)	adds a flag	flag&
add_flag(name, alt_name)	adds a flag with an alternative name	flag&
help_flag(name, alt_name = "")	sets the help flag name/names	flag&
version_flag(name, alt_name = "")	sets the help flag name/name	flag&
make_help()	returns help page	std::string
make_version_info()	returns version information	std::string
parse(argc, argv)	parses command line arguments	bool (true if successful, false otherwise)
wrong	const std::vector<std::string>& that contains parsing errors

flag class

Member	Description	Return value
flag()	constructor
~flag()	destructor
set(ref)	sets the variable to write to	flag&
req()	sets the flag to be required	flag&
doc(doc)	sets the flag description	flag&
doc()	gets the flag description	const std::string&

option class

It is a template class that allows only: int, float, std::string and char.

Member	Description	Return value
option()	constructor
~option()	destructor
set(value_name, ref)	sets the variable to write to and the value name (e.g. file, charset)	option&
set(value_name, ref, def)	sets the variable to write to with default value and the value name (e.g. file, charset)	option&
req()	sets the option to be required	option&
match(...)	sets allowed values	option&
doc(doc)	sets the option description	option&
doc()	gets the option description	const std::string&

License

This project is licensed under the MIT License.