ini.h

ini.h is a header-only library for reading and writing INI files in C++ through a simple, intuitive API.

Table of Contents

• Preface
  • Prerequisites
• Usage
  • Reading and Writing INI Files
  • Getting and Setting Values
• Features
  • Comments
  • Case Sensitivity
  • Delimiters
• Documentation

Preface

To start using ini.h, copy the single header file and drop it into your project. Now you can use the library by adding the following directive:

#include "ini.h"

Prerequisites

• C++17 or higher

Usage

Reading and Writing INI Files

There are two ways to read and parse INI files with ini.h:

1. Through a file path
2. Through a file stream

File Path

#include "ini.h"

int main(int argc, char* argv[])
{
    ini::File file = ini::open("path/to/ini/example.ini");
}

File Stream

#include <fstream>
#include "ini.h"

int main(int argc, char* argv[])
{
    std::ifstream stream("path/to/ini/example.ini");
    ini::File file = ini::load(stream);

    // You are responsible for closing the file stream.
    stream.close();
}

As for writing, simply pass the destination path to the write function.

Writing to an INI File

#include "ini.h"

int main(int argc, char* argv[])
{
    ini::File file = ini::open("path/to/ini/example.ini");

    file.add_section("New Section");
    file["New Section"]["is_generic_key"] = "true";

    file.write("path/to/ini/example.ini");
}

Getting and Setting Values

You can retrieve values by using the operator[] but this will only return a string value. If you need a value in the form of a bool, for example, you can do so by using the get function.

Getting Values

#include "ini.h"

int main(int argc, char* argv[])
{
    ini::File file = ini::open("path/to/ini/example.ini");

    std::string title = file["FileInfo"]["title"];
    bool auto_save_enabled = file["FileInfo"].get<bool>("autoSaveEnabled"):
    size_t word_count = file["FileInfo"].get<size_t>("wordCount");
    double line_spacing = file["FileInfo"].get<double>("lineSpacing");
}

example.ini

[FileInfo]
title = On the topic of C++
author = John Appleseed
lastDateOpened = 2022-07-24
autoSaveEnabled = true
wordCount = 0
lineSpacing = 1.5

Setting values with can also be done with the subscript operator but this requires a string representation of the value you're trying to set.

If you already have a bool, a double, etc., you can simply use the set function. Those values will automatically be converted into a string representation for you.

Setting Values

#include "ini.h"

int main(int argc, char* argv[])
{
    ini::File file = ini::open("path/to/ini/example.ini");

    file["FileInfo"]["title"] = "On the topic of C#";
    file["FileInfo"].set<bool>("autoSaveEnabled", false);
    file["FileInfo"].set<size_t>("wordCount", 1);
    file["FileInfo"].set<double>("lineSpacing", 2.0);
}

example.ini

[FileInfo]
title = On the topic of C++
author = John Appleseed
lastDateOpened = 2022-07-24
autoSaveEnabled = true
wordCount = 0
lineSpacing = 1.5

Features

Comments

• ; comment text
• # comment text

ℹ️ Comments must start at the beginning of a line.

Case Sensitivity

Section names and keys are case-sensitive.

example.ini

[SECTION]
key = value
KEY = value

[section]
key = value
KEY = value

Delimiters

• =
• :

example.ini

[Section]
key1 = value
key2 : value

Supported Value Types

• int
• float
• double
• size_t
• std::size_t
• std::string

Documentation

You can view more in-depth, MSDN-style documentation on the ini.h library here.