gistfile1.txt

//
// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/vinniefalco/json
//

/*
    This example parses a JSON file and pretty-prints
    it to standard output.
*/

#include <boost/json.hpp>
#include <fstream>
#include <iostream>

namespace json = boost::json;

json::value
parse(std::istream& is)
{
    json::parser p;
    json::error_code ec;
    p.start();
    auto const exceptions = is.exceptions();
    is.exceptions(std::ios_base::iostate::
    do
    {
        char buf[4096];
        is.read(buf, sizeof(buf));
        auto const n = is.gcount();
        p.write(buf, n, ec);
        if(ec)
            throw json::system_error(ec);
    }
    while(! is.eof());
    p.write_eof(ec);
    if(ec)
        throw json::system_error(ec);
    return p.release();
}

void
pretty_print(

int
main(int argc, char** argv)
{
    if(argc != 2)
    {
        std::cerr <<
            "Usage: pretty <filename>"
            << std::endl;
        return EXIT_FAILURE;
    }

    try
    {
        // Open the file
        std::ifstream ifs(argv[1]);

        ifs.exceptions(
        // Parse the file as JSON
        auto const jv = parse(ifs);

        // Now pretty-print the value
        pretty_print(std::cout, jv);
    }
    catch(std::exception const& e)
    {
        std::cerr <<
            "Caught exception: "
            << e.what() << std::endl;
        return EXIT_FAILURE;
    }

    return EXIT_SUCCESS;
}