http://it-ebooks.info Downloader

it-ebooks.info Downloader.cs

using System;
using System.IO;
using System.Net;
using System.Text;
using System.Threading;

public static class Program
{
	private const string BookUrlPattern = "http://it-ebooks.info/book/{0}/";

	public static void Main()
	{
		string filesPath = Environment.CurrentDirectory + "\\Books";
		Directory.CreateDirectory(filesPath);

		for (int i = 1; i < 2000; i++)
		{
			var webClient = new WebClient();
			var html = webClient.DownloadString(string.Format(BookUrlPattern, i));

			if (!html.Contains("<h1 itemprop="))
			{
				// Book not found!
				Console.WriteLine("Book #{0} => Not found!", i);
				continue;
			}

			var bookName = html.GetStringBetween("<h1 itemprop=\"name\">", "</h1>");
			var downloadLink = "http://it-ebooks.info" + html.GetStringBetween("<a id=\"dl\" href=\"", "\"");
			var year = html.GetStringBetween("<b itemprop=\"datePublished\">", "</b>").ToInteger();

			Directory.CreateDirectory(string.Format("{0}\\{1}", filesPath, year));

			var filePath = string.Format("{0}\\{1}\\{2}", filesPath, year, bookName.ToValidFileName());
			webClient.DownloadFile(downloadLink, filePath);

			var fileExtension = webClient.ResponseHeaders["Content-Disposition"].GetFileExtension();

			if (File.Exists(string.Format("{0}.{1}", filePath, fileExtension)))
			{
				File.Delete(filePath);
			}
			else
			{
				File.Move(filePath, string.Format("{0}.{1}", filePath, fileExtension));
			}

			Console.WriteLine("Book #{0} => {1}", i, bookName);

			// Wait 2 seconds so they won't threat the bot as flooder
			Thread.Sleep(1000);
		}
	}
}

public static class StringExtensions
{
	public static string GetStringBetween(this string text, string startString, string endString, int startFrom = 0)
	{
		text = text.Substring(startFrom);
		startFrom = 0;
		if (!text.Contains(startString) || !text.Contains(endString))
		{
			return string.Empty;
		}

		var startPosition = text.IndexOf(startString, startFrom, StringComparison.Ordinal) + startString.Length;
		if (startPosition == -1)
		{
			return string.Empty;
		}

		var endPosition = text.IndexOf(endString, startPosition, StringComparison.Ordinal);
		if (endPosition == -1)
		{
			return string.Empty;
		}

		return text.Substring(startPosition, endPosition - startPosition);
	}

	public static int ToInteger(this string text)
	{
		int integerValue;
		int.TryParse(text, out integerValue);
		return integerValue;
	}

	public static string ToValidFileName(this string fileName)
	{
		var invalidCharacters = Path.GetInvalidFileNameChars();
		var fixedString = new StringBuilder(fileName);
		foreach (var ch in invalidCharacters)
		{
			fixedString.Replace(ch, '_');
		}

		return fixedString.ToString();
	}

	public static string GetFileExtension(this string text)
	{
		var parts = text.Split('.');
		return parts[parts.Length - 1];
	}
}