Reading/writing an INI file

Question

Is there any class in the .NET framework that can read/write standard .ini files:

[Section]
<keyname>=<value>
...

Delphi has the TIniFile component and I want to know if there is anything similar for C#?

Answer 1

I found this simple implementation:

http://bytes.com/topic/net/insights/797169-reading-parsing-ini-file-c

Works well for what I need.

Here is how you use it:

public class TestParser
{
    public static void Main()
    {
        IniParser parser = new IniParser(@"C:\test.ini");

        String newMessage;

        newMessage = parser.GetSetting("appsettings", "msgpart1");
        newMessage += parser.GetSetting("appsettings", "msgpart2");
        newMessage += parser.GetSetting("punctuation", "ex");

        //Returns "Hello World!"
        Console.WriteLine(newMessage);
        Console.ReadLine();
    }
}

Here is the code:

using System;
using System.IO;
using System.Collections;

public class IniParser
{
    private Hashtable keyPairs = new Hashtable();
    private String iniFilePath;

    private struct SectionPair
    {
        public String Section;
        public String Key;
    }

    /// <summary>
    /// Opens the INI file at the given path and enumerates the values in the IniParser.
    /// </summary>
    /// <param name="iniPath">Full path to INI file.</param>
    public IniParser(String iniPath)
    {
        TextReader iniFile = null;
        String strLine = null;
        String currentRoot = null;
        String[] keyPair = null;

        iniFilePath = iniPath;

        if (File.Exists(iniPath))
        {
            try
            {
                iniFile = new StreamReader(iniPath);

                strLine = iniFile.ReadLine();

                while (strLine != null)
                {
                    strLine = strLine.Trim().ToUpper();

                    if (strLine != "")
                    {
                        if (strLine.StartsWith("[") && strLine.EndsWith("]"))
                        {
                            currentRoot = strLine.Substring(1, strLine.Length - 2);
                        }
                        else
                        {
                            keyPair = strLine.Split(new char[] { '=' }, 2);

                            SectionPair sectionPair;
                            String value = null;

                            if (currentRoot == null)
                                currentRoot = "ROOT";

                            sectionPair.Section = currentRoot;
                            sectionPair.Key = keyPair[0];

                            if (keyPair.Length > 1)
                                value = keyPair[1];

                            keyPairs.Add(sectionPair, value);
                        }
                    }

                    strLine = iniFile.ReadLine();
                }

            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                if (iniFile != null)
                    iniFile.Close();
            }
        }
        else
            throw new FileNotFoundException("Unable to locate " + iniPath);

    }

    /// <summary>
    /// Returns the value for the given section, key pair.
    /// </summary>
    /// <param name="sectionName">Section name.</param>
    /// <param name="settingName">Key name.</param>
    public String GetSetting(String sectionName, String settingName)
    {
        SectionPair sectionPair;
        sectionPair.Section = sectionName.ToUpper();
        sectionPair.Key = settingName.ToUpper();

        return (String)keyPairs[sectionPair];
    }

    /// <summary>
    /// Enumerates all lines for given section.
    /// </summary>
    /// <param name="sectionName">Section to enum.</param>
    public String[] EnumSection(String sectionName)
    {
        ArrayList tmpArray = new ArrayList();

        foreach (SectionPair pair in keyPairs.Keys)
        {
            if (pair.Section == sectionName.ToUpper())
                tmpArray.Add(pair.Key);
        }

        return (String[])tmpArray.ToArray(typeof(String));
    }

    /// <summary>
    /// Adds or replaces a setting to the table to be saved.
    /// </summary>
    /// <param name="sectionName">Section to add under.</param>
    /// <param name="settingName">Key name to add.</param>
    /// <param name="settingValue">Value of key.</param>
    public void AddSetting(String sectionName, String settingName, String settingValue)
    {
        SectionPair sectionPair;
        sectionPair.Section = sectionName.ToUpper();
        sectionPair.Key = settingName.ToUpper();

        if (keyPairs.ContainsKey(sectionPair))
            keyPairs.Remove(sectionPair);

        keyPairs.Add(sectionPair, settingValue);
    }

    /// <summary>
    /// Adds or replaces a setting to the table to be saved with a null value.
    /// </summary>
    /// <param name="sectionName">Section to add under.</param>
    /// <param name="settingName">Key name to add.</param>
    public void AddSetting(String sectionName, String settingName)
    {
        AddSetting(sectionName, settingName, null);
    }

    /// <summary>
    /// Remove a setting.
    /// </summary>
    /// <param name="sectionName">Section to add under.</param>
    /// <param name="settingName">Key name to add.</param>
    public void DeleteSetting(String sectionName, String settingName)
    {
        SectionPair sectionPair;
        sectionPair.Section = sectionName.ToUpper();
        sectionPair.Key = settingName.ToUpper();

        if (keyPairs.ContainsKey(sectionPair))
            keyPairs.Remove(sectionPair);
    }

    /// <summary>
    /// Save settings to new file.
    /// </summary>
    /// <param name="newFilePath">New file path.</param>
    public void SaveSettings(String newFilePath)
    {
        ArrayList sections = new ArrayList();
        String tmpValue = "";
        String strToSave = "";

        foreach (SectionPair sectionPair in keyPairs.Keys)
        {
            if (!sections.Contains(sectionPair.Section))
                sections.Add(sectionPair.Section);
        }

        foreach (String section in sections)
        {
            strToSave += ("[" + section + "]\r\n");

            foreach (SectionPair sectionPair in keyPairs.Keys)
            {
                if (sectionPair.Section == section)
                {
                    tmpValue = (String)keyPairs[sectionPair];

                    if (tmpValue != null)
                        tmpValue = "=" + tmpValue;

                    strToSave += (sectionPair.Key + tmpValue + "\r\n");
                }
            }

            strToSave += "\r\n";
        }

        try
        {
            TextWriter tw = new StreamWriter(newFilePath);
            tw.Write(strToSave);
            tw.Close();
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    /// <summary>
    /// Save settings back to ini file.
    /// </summary>
    public void SaveSettings()
    {
        SaveSettings(iniFilePath);
    }
}

Answer 2

Here is my own version, using regular expressions. This code assumes that each section name is unique - if however this is not true - it makes sense to replace Dictionary with List. This function supports .ini file commenting, starting from ';' character. Section starts normally [section], and key value pairs also comes normally "key = value". Same assumption as for sections - key name is unique.

/// <summary>
/// Loads .ini file into dictionary.
/// </summary>
public static Dictionary<String, Dictionary<String, String>> loadIni(String file)
{
    Dictionary<String, Dictionary<String, String>> d = new Dictionary<string, Dictionary<string, string>>();

    String ini = File.ReadAllText(file);

    // Remove comments, preserve linefeeds, if end-user needs to count line number.
    ini = Regex.Replace(ini, @"^\s*;.*$", "", RegexOptions.Multiline);

    // Pick up all lines from first section to another section
    foreach (Match m in Regex.Matches(ini, "(^|[\r\n])\\[([^\r\n]*)\\][\r\n]+(.*?)(\\[([^\r\n]*)\\][\r\n]+|$)", RegexOptions.Singleline))
    {
        String sectionName = m.Groups[2].Value;
        Dictionary<String, String> lines = new Dictionary<String, String>();

        // Pick up "key = value" kind of syntax.
        foreach (Match l in Regex.Matches(ini, @"^\s*(.*?)\s*=\s*(.*?)\s*$", RegexOptions.Multiline))
        {
            String key = l.Groups[1].Value;
            String value = l.Groups[2].Value;

            // Open up quotation if any.
            value = Regex.Replace(value, "^\"(.*)\"$", "$1");

            if (!lines.ContainsKey(key))
                lines[key] = value;
        }

        if (!d.ContainsKey(sectionName))
            d[sectionName] = lines;
    }

    return d;
}

Answer 3

Preface

Firstly, read this MSDN blog post on the limitations of INI files. If it suits your needs, read on.

This is a concise implementation I wrote, utilising the original Windows P/Invoke, so it is supported by all versions of Windows with .NET installed, (i.e. Windows 98 - Windows 10). I hereby release it into the public domain - you're free to use it commercially without attribution.

The tiny class

Add a new class called IniFile.cs to your project:

using System.IO;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;

// Change this to match your program's normal namespace
namespace MyProg
{
    class IniFile   // revision 11
    {
        string Path;
        string EXE = Assembly.GetExecutingAssembly().GetName().Name;

        [DllImport("kernel32", CharSet = CharSet.Unicode)]
        static extern long WritePrivateProfileString(string Section, string Key, string Value, string FilePath);

        [DllImport("kernel32", CharSet = CharSet.Unicode)]
        static extern int GetPrivateProfileString(string Section, string Key, string Default, StringBuilder RetVal, int Size, string FilePath);

        public IniFile(string IniPath = null)
        {
            Path = new FileInfo(IniPath ?? EXE + ".ini").FullName.ToString();
        }

        public string Read(string Key, string Section = null)
        {
            var RetVal = new StringBuilder(255);
            GetPrivateProfileString(Section ?? EXE, Key, "", RetVal, 255, Path);
            return RetVal.ToString();
        }

        public void Write(string Key, string Value, string Section = null)
        {
            WritePrivateProfileString(Section ?? EXE, Key, Value, Path);
        }

        public void DeleteKey(string Key, string Section = null)
        {
            Write(Key, null, Section ?? EXE);
        }

        public void DeleteSection(string Section = null)
        {
            Write(null, null, Section ?? EXE);
        }

        public bool KeyExists(string Key, string Section = null)
        {
            return Read(Key, Section).Length > 0;
        }
    }
}

How to use it

Open the INI file in one of the 3 following ways:

// Creates or loads an INI file in the same directory as your executable
// named EXE.ini (where EXE is the name of your executable)
var MyIni = new IniFile();

// Or specify a specific name in the current dir
var MyIni = new IniFile("Settings.ini");

// Or specify a specific name in a specific dir
var MyIni = new IniFile(@"C:\Settings.ini");

You can write some values like so:

MyIni.Write("DefaultVolume", "100");
MyIni.Write("HomePage", "http://www.google.com");

To create a file like this:

[MyProg]
DefaultVolume=100
HomePage=http://www.google.com

To read the values out of the INI file:

var DefaultVolume = IniFile.Read("DefaultVolume");
var HomePage = IniFile.Read("HomePage");

Optionally, you can set [Section]'s:

MyIni.Write("DefaultVolume", "100", "Audio");
MyIni.Write("HomePage", "http://www.google.com", "Web");

To create a file like this:

[Audio]
DefaultVolume=100

[Web]
HomePage=http://www.google.com

You can also check for the existence of a key like so:

if(!MyIni.KeyExists("DefaultVolume", "Audio"))
{
    MyIni.Write("DefaultVolume", "100", "Audio");
}

You can delete a key like so:

MyIni.DeleteKey("DefaultVolume", "Audio");

You can also delete a whole section (including all keys) like so:

MyIni.DeleteSection("Web");

Please feel free to comment with any improvements!

Answer 4

This article on CodeProject "An INI file handling class using C#" should help.

The author created a C# class "Ini" which exposes two functions from KERNEL32.dll. These functions are: WritePrivateProfileString and GetPrivateProfileString. You will need two namespaces: System.Runtime.InteropServices and System.Text.

Steps to use the Ini class

In your project namespace definition add

using INI;

Create a INIFile like this

INIFile ini = new INIFile("C:\\test.ini");

Use IniWriteValue to write a new value to a specific key in a section or use IniReadValue to read a value FROM a key in a specific Section.

Note: if you're beginning from scratch, you could read this MSDN article: How to: Add Application Configuration Files to C# Projects. It's a better way for configuring your application.

Answer 5

If you want just a simple reader without sections and any other dlls here is simple solution:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Tool
{
    public class Config
    {
        Dictionary <string, string> values;
        public Config (string path)
        {
            values = File.ReadLines(path)
            .Where(line => (!String.IsNullOrWhiteSpace(line) && !line.StartsWith("#")))
            .Select(line => line.Split(new char[] { '=' }, 2, 0))
            .ToDictionary(parts => parts[0].Trim(), parts => parts.Length>1?parts[1].Trim():null);
        }
        public string Value (string name, string value=null)
        {
            if (values!=null && values.ContainsKey(name))
            {
                return values[name];
            }
            return value;
        }
    }
}

Usage sample:

    file = new Tool.Config (Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location) + "\\config.ini");
    command = file.Value ("command");
    action = file.Value ("action");
    string value;
    //second parameter is default value if no key found with this name
    value = file.Value("debug","true");
    this.debug = (value.ToLower()=="true" || value== "1");
    value = file.Value("plain", "false");
    this.plain = (value.ToLower() == "true" || value == "1");

Config file content meanwhile (as you see supports # symbol for line comment):

#command to run
command = php

#default script
action = index.php

#debug mode
#debug = true

#plain text mode
#plain = false

#icon = favico.ico