CurlSharp

CurlSharp is a modern C# (5.0/async) binding against libcurl with a System.Net.Http.HttpMessageHandler implementation for use with .NET 4.5's System.Net.Http.HttpClient.

Incomplete, Barely Tested, Proof of Concept

CurlSharp is a brand new project hacked on in spare time (started Jan 7, 2014). It's sort of an itch scratcher that may prove genuinely useful at some point (e.g. to avoid using the default System.Net.HttpWebRequest backend when using System.Net.Http.HttpClient, which has its own set of issues).

As such, do not use it in production. You will probably find that much is missing. For example, POST isn't supported. That's useful.

Please do try it out and file issues on Github, however!

Classes

CurlHttpClientHandler

This class derives from System.Net.Http.HttpMessageHandler and can be used with System.Net.Http.HttpClient to provide a cURL-powered HTTP experience in .NET. This is the easiest and recommended way to use this library.

var client = new HttpClient (new CurlHttpClientHandler ());
var cats = client.GetStringAsync ("http://catoverflow.com/api/query").Result;
Console.WriteLine (cats);

Easy

This class implements a wrist and code completion friendly binding over the cURL easy API, which is the core API for interacting with cURL. It is a blocking and single-threaded API.

using (var stdout = Console.OpenStandardOutput ()) {
	using (var easy = new Easy {
		Url = "http://catoverflow.com/api/query",
		WriteHandler = buffer => stdout.Write (buffer, 0, buffer.Length)
	}) {
		easy.Perform ();
	}
	stdout.Flush ();
}

Multi

This class implements a wrist and code completion friendly binding over the cURL multi API, which provides facilities for non-blocking IO and sits atop the cURL easy API. It supports select operations on fd_set handles provided by cURL for efficient IO, though using this API is optional.

using (var stdout = Console.OpenStandardOutput ()) {
	using (var multi = new Multi {
		new Easy {
			Url = "http://catoverflow.com/api/query",
			WriteHandler = buffer => stdout.Write (buffer, 0, buffer.Length)
		}
	}) {
		do {
			multi.AutoPerformWithSelect ();
		} while (multi.HandlesRemaining > 0);
	}
	stdout.Flush ();
}

Native

This class provides an extremely thin P/Invoke layer over the actual libcurl API. Using this API is very much like working with cURL's raw C API.

using (var stdout = Console.OpenStandardOutput ()) {
	var easy = Native.Easy.Init ();
	try {
		Native.Easy.SetOpt (easy, Native.Option.URL, "http://catoverflow.com/api/query");
		Native.Easy.SetOpt (easy, Native.Option.WRITEFUNCTION, (data, size, nmemb, user) => {
			var length = (int)size * (int)nmemb;
			var buffer = new byte [length];
			System.Runtime.InteropServices.Marshal.Copy (data, buffer, 0, length);
			stdout.Write (buffer, 0, length);
			return (IntPtr)length;
		});
		Native.Easy.Perform (easy);
		stdout.Flush ();
	} finally {
		if (easy != IntPtr.Zero)
			Native.Easy.Cleanup (easy);
	}
}

CurlResponseStream

This class provides the most .NET-familiar wrapper that does not integrate into any real framework (e.g. like CurlHttpClientHandler). It derives from System.IO.Stream and takes either a Curl.Multi and a Curl.Easy or just a Curl.Easy.

It then consumes these objects to provide a standard .NET read-only stream with efficient select-based IO. This class is used by CurlHttpClientHandler to perform the bulk of its work.

var easy = new Easy { Url = "http://catoverflow.com/api/query" };
using (var stream = new CurlResponseStream (easy))
	Console.WriteLine (new StreamReader (stream).ReadToEnd ());