What I want to do is read a webpage and then store it in a sting I know how to do this using libcurl but is there any other way to do this without using libcurl?(Using Cygwin to compile)
You can implement a simple HTTP request using raw sockets. But for other than learning exercises I would not recommend this and just go with libcurl.
For an example program which uses raw sockets look here: http://coding.debuntu.org/c-linux-socket-programming-tcp-simple-http-client (randomly found on google, quality not assured).
While you can easily create an HTTP client using raw sockets as the other posters have suggested, I recommend against it if you want to deploy your software anywhere outside of your own computer. In the real world your users are likely to be behind proxies and firewalls, and may require authentication. Libraries like libCurl deal with this complexity for you.
If you really can't use libCurl and don't care about cross-platform code, most operating systems have built in APIs for accessing web pages. WinINET is the Windows library.
You can always speak HTTP directly yourself over a socket.
Related
I am building a server-client application that involves heavy signal processing (e.g. FFT). I have a working application written in C++/Qt, where everything (signal processing and other calculations) is done in client and server just sends raw data. Now I feel it would be easier to implement these features on the server. So, that maintenance becomes easier.
As I am doing signal processing, I think I should stick to C++ for performance. But I am open to new ideas.
Constraints:
I need type checking so javascript is out of discussion.
Scaling includes adding more server and each server will have at the max
10-12 users. So, Hardware cost is important. I cannot use x number of
i7 processors.
No option of using cloud services.
So, right now my question is as follows:
How can I create web services using C++ for Linux server? (Although cross platform is not important, I would appreciate if I can achieve it.)
EDIT [02:09:2015]
Right now, I think the choice is between poco and C++ Rest SDK. I feel I should go for C++ Rest SDK. Mainly because it has only those features that I need. And Also it is supported by microsoft and uses boost internally. So, I feel in future, this might be well integreated with standard.
You could use cross-platform Poco library to implement HTTP server, it is really straightforward with this framework, and they have a lot of examples. You can also use JSON serialization (like rapidjson library) to implement REST service on top of HTTP - this way your Web service will be accesable by most of the modern Web frameworks.
You might want to take a look at the C++ Rest SDK, an open source, cross platform API from Microsoft.
Like #nogard suggested, I also recommend POCO for now. It's the most serious and feature-full solution. Given you mentioned Qt, I suggest you to take a look at Tufão.
EDIT:
I forgot to mention one comparison of mine on the C++ HTTP server frameworks.
If you directly handle HTTP requests, you might loose the functionality what Web Servers does well what it was build to do. I had a similar issue, what I did was wrap up my Qt c++ code inside a PHP extension. In your case you can do the same. Wrap your logic inside what ever technology you are about to use, doesn't matter it's PHP, net , Java or anything else.
I need to download files/read strings from a specified url in C++. I've done some research with this, cURL seems to be the most popular method. Also, I've used it before in PHP. The problem with cURL is that the lib is huge, and my file has to be small. I think you can do it with winsock, but I can't find any simple examples. If you have a simple winsock example, a light cURL/Something else, or anything that could get the job done. I would greatly appreciated. Also, I need this to work with native C++.
I can repeat me answer Is it possible to handle proxies at socket level? (see also comments) about two important interfaces Windows Internet (WinINet) API and Windows HTTP Services (WinHTTP). An important restriction of WinINet is that WinINet should be not used in a service (only in GUI app.) because of possible dialogs.
you should try WinInet: this library is part of Windows operating system, and allows to download a resource identified by an URL, using either HTTP or FTP.
if you are using HTTP, you might find the InternetOpenUrl() function useful.
Basically my question is the exact same one as this:
Simple client/server, TCP/IP encrypting the message stream, SSL
The difference is that I need this for pure C++, not .NET. I cannot use 3rd party libraries, so unless it's a Windows system component (like the above) I need something with source so I can get the generel idea and build it myself.
Thanks :)
Quoting the other question for reference:
"Writing a little TCP/IP client server
app. Basically it creates a server,
and then you can create several
different clients and set up a bit of
a chat session. What I am wondering is
there is any way to incorporate, using
standard .net libraries some form of
encryption?
m_mainSocket = new
Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
Is there any way of speficying tcp
using rsa?
Or would you (me that is) have to
write some custom libaries to do key
exchange and then encrypt the
subsequent chat messages? I have done
that before for uni but that was in
java but I know it would'nt be hard to
convert them. Just trying not to have
to reinvent the wheel...
Or what about utilising a ssl?
Thanks, Ron."
Have you considered using the ASIO library? think-async dot com/Asio/
There is an example specifically for an SSL based client/server. http://think-async.com/Asio/asio-1.4.1/doc/asio/examples.html#asio.examples.ssl
Its as "pure c++" as you can get.
You can always look at OpenSSL which is open source, but that would be like implement SSL yourself. I would suggest wrapping OpenSSL and use it. Or use the SSL tunnel application available in OpenSSL.
Writing your own encryption code is "not recommended". It's easy enough to make a simple mistake when using one of these libraries, let alone when you try to write one yourself.
What you really want to use is OpenSSL with Boost.ASIO on top of it. If you can't do that then your next best alternative is to use the Internet Explorer COM object. This isn't quite as flexible, but might work out fine depending on what your exact needs are. You can also explore the Win32 API. Last I looked there weren't enough crypto APIs widely available to do this. The final way of dealing with this is to wrap the .NET APIs so that you can make use of them from native C++.
Only if none of that works out for you should you even consider writing this yourself. You will make mistakes and your application will be less secure as a result. So, before you start trying to write your own crypto code you could also try to look at tunnelling SOCKS over SSH and use somebody else's SSH implementation. The next thing I would look at is to buy in the code rather than write it yourself. The code won't be as good as open source offerings as it will be less used so will have more security problems, but it will still be better than anything you would write on your first outing doing this.
Only if you've exhausted all of these options should you think about writing this yourself. Once you think about it you should try all of the other options again to make sure that you didn't miss getting one of them to work for you the first time around.
If you do still write your own implementation then throw it away and use one of the other options before putting it into production use as there will be mistakes that compromise the security to the extent where you probably may as well not have bothered.
Sorry to sound down on all of this, but getting these things right is really hard and not something you can do by just taking a quick look at somebody else's implementation.
Can someone give me an example of a Unmanaged C++ HTML Client with proxy support?
I want to do some get and posts inside my unmanaged c++ programs, ideally I would like to allow for proxy server configuration, or just use the IE defaults.
I am not looking for hand outs, just something to go by, as I can't seem to find too much on this.
What, seriously?
Call WinHttpGetIEProxyConfigForCurrentUser to get the proxy configuration and then use the HTTP stack of your choice. I would avoid implementing your own psuedo HTTP stack, getting it right is more work then you probably think.
I'd start with Boost.ASIO. It does not deliver out-of-the-box what you request, there are more complete libraries out there, it just happens that I don't know them.
If you're developing on Windows, you can use WinHttp to write a C++ HTTP client, I just finished implementing a client with it here at work.
WinHttp is a fairly straightforward API to use and takes care of all the HTTP communication details for you.
I have recently been given a task to add the ability to interact with Web Map Services to an existing MFC application and I am in need of a client-side HTTP API.
Based on my research, the leading candidates seem to be CAtlHttpClient and WinHTTP. I was curious to see if anyone had experiences they could share or opinions on which would be the better way to go (or suggestions for something else entirely).
At first glance, CAtlHttpClient seems to be a bit higher level and easier to use. However, in my research it seemed that any time people had a problem with not being able to do something with it, the answer was "use WinHTTP".
Result
I wound up using WinHTTP because WinInet displays dialog boxes and our application is usable through a COM API. I avoided Ultimate TCP/IP because I work for a large company and getting third party software approved for use in a product is a complete nightmare.
The simplest one is the WinInet MFC wrappers: CInternetSession and friends.
WinHTTP, although a different API, is built on the same model as WinInet yet provides better HTTP support (no FTP though but you probably don't care). Whether you need the extra goodies provided by WinHTTP should be examined.
A down side of WinHTTP is that ATL/MFC don't provide wrappers for it, as opposed to WinInet.
And as Rob mentioned, UltimateTCP is a excellent alternative. One of its advantages is that it's a library: you link the code into your application, thereby eliminating DLL hell potential problems. Also, it comes with full source code which might be convenient if you run into a limitation of the implementation.
Make your pick!
Try Ultimate TCP/IP available for free from here:
http://www.codeproject.com/KB/MFC/UltimateTCPIP.aspx
It's a very good library and very easy to integrate with your apps.