can anyone suggest a good HTTP parsing library for linux?
libcurl?
It supports most web-based protocols, widely used, and stable. Available on most Linux distributions and should be around for Windows too. It supports both a simplified interface for quick-and-dirty implementations as well as an advanced interface for a robust implementation.
If you need a C++ wrapper for curl, you might like curl++. Do look it up.
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I think it is better if I explain the situation so this doesn't seem too arcane a question. I want to release some starter code for a project I want some of my students to work on. The project involves scraping through some internet webpages and as such, I want to provide them with a URLStream class that will download the html of an input url and return it as a string to them.
The issue is that I can't seem to find a particularly nice way to deal with networking in a way that will be cross platform (the students have mac/windows/linux machines). I know of libraries like Boost asio and libCurl, but the issue with using these is that I can't enforce all my students download them. So my question is twofold:
Is there any nice way to provide them this cross platform networking code?
If a library is the only way to do this, is there any way to attach the library to the starter project so that students don't have to download it? I know this might be a stupid question but I can't seem to find out if this is possible.
Boost.Asio is really not suitable for your needs as it involves huge Boost and building at least some of its non-header-only libs. You can still consider Asio lib that can be used w/o Boost and is header-only lib, so much less hassle for you and your students. As it's probably the most popular and modern networking C++ lib this exercise can provide some useful experience to the students. Asio examples also have a simple HTTP client.
As a side note, are you bound to C++ for this assignment? It would be much simpler in Python or similar languages that provide networking out of the box.
The Berkeley sockets API is the most common low-level socket API. It is supported on all POSIX platforms which means both Linux and macOS will have it.
Even Windows have it, but with a slight twist since sockets aren't descriptors like they are on POSIX systems.
Using sockets directly will lead to more boiler-plate code, but it is definitely possible to use it to make a simple HTTP client that supports only simple GET requests.
There are many tutorials and references on using sockets. Beej's Guide to Network Programming seems to be a popular tutorial, which should have notes about the tweaks needed for Windows.
cross-platform C++ library for network programming
asio is a cross-platform C++ library for network programming that provides
developers with a consistent asynchronous I/O model using a modern C++
approach. It has recently been accepted into Boost.
I copied that from the info window in Synaptic. If you're using Linux, install the library (and its documentation) thus:
sudo apt-get install libasio-dev libasio-doc
I am thinking of creating a multi-platform portable C++ server-client application. Is it even possible while using only standard libraries? If no, what other libraries are there?
Are there any improvements in this direction in C++11x? Like for threads, now we have std::threads.
To make it more clear.. I want something like boost::thread, which provides multiplatform portable multithreading, for networking.
And why C++ doesn't have libraries(standard) for such basic things like networking?
Update: Comparing to Python, which has everything (almost) built in to it... why not in C++?
There is Boost Asio. It has existed for "only" a small number of years...long ago we had ACE, but it feels dated now.
There is no standard portable option in C++11.
However the portable boost::asio is one of the best networking API's. It is based on the proactor pattern which is very efficient.
http://www.boost.org/doc/libs/1_49_0/doc/html/boost_asio.html
There have been many attempts to provide such a cross-platform library for networking over the years. The Berkeley socket library comes pretty close (and probably comes with your OS), but there are still platform-specific differences. Qt has network socket classes that attempt to be cross-platform within the subset of platforms that Qt normally supports. You can probably find lots of others.
There is no language standard networking library for C or C++ analogous to std::thread.
What is the most basic way to go to a webpage and download its contents? the webpage i wish to get only has text, most of which is in tables.
is there a std library that does it (like urllib in python)?
There's no official C++ network library, no. There are many different APIs available, though. Which is best for you would depend on what platform(s) you were targeting and what framework(s) you might already be using.
That said, cpp-netlib is a platform-neutral API that follows C++ idioms nicely. I've used it and it works.
A large number of tasks that are not covered by the C++ standard library can be done using boost, the collection of peer-reviewed portable libraries, which are used by pretty much every C++ project today. For networking, we use boost.asio.
Their tutorials include HTTP clients: http://www.boost.org/doc/libs/1_46_1/doc/html/boost_asio/example/http/client/sync_client.cpp and http://www.boost.org/doc/libs/1_46_1/doc/html/boost_asio/example/http/client/async_client.cpp
However, although this is highly portable and may end up becoming part of the C++ standard library in future, it is a bit too low-level for your task. libCURL is the today's default library for HTTP downloads.
are there any library similar to apache httpcomponents for c/c++ language?
Thanks in advance,
Dario.
I'm not sure how similar they are to those particular Apache components, but you might want to look at POCO and ACE. Both provide quite a bit in the way of networking in C++. ACE tends to be the more all-encompassing of the two (both in terms of supporting lots of protocols and such, and in terms of tending to control/dominate all of how an application is written/works).
Depending on exactly what you're after, you could also look at Boost.asio and/or LibCurl.
I have a set of functions in C/C++ that I need to be available to accept calls and return values to C/C++ code in a remote location, similar to RMI on the java platform. With RMI the Java methods are set up through the rmiregistry and remain available in memory to accept requests. I'm looking for similar functionality in C/C++, but i'm a bit confused with all the options that are out there. Is this type of scenario that CORBA was intended for and if so, is this still the best technology to use or are there better options out there. I've read about XML-RPC, CORBA, and a few others but i'm not sure which of these is what i need.
Thanks for your help.
Mike
Is this type of scenario that CORBA was intended for and if so, is this still the best technology to use or are there better options out there.
Yes, this is what CORBA was intended to solve. Whether it's "best" is subjective and argumentative. :) I can say, from my personal experience, I don't miss my short experience with CORBA and would suggest you explore other options.
I've read about XML-RPC, CORBA, and a few others but i'm not sure which of these is what i need.
As you seem to be aware, you're looking for any technology that implements RMI (also frequently called RPC). It's not built-in to C/C++.
On Linux, there is SunRPC. I would also recommend looking at Google protocol buffers, which provide a mechanism for serializing data as well as an interface for defining RPC services. There are several service implementations available, but I don't have experience with the service implementations.
On Unix-like platforms, you're probably looking for Sun RPC (remote procedure calls).
CORBA is also relevant but has a more natural binding to languages with object oriented capability.
There's no built in method for accomplishing this in C or C++. That said there are several libraries that can accomplish this.
If you're on Windows, then the best answer is probably DCOM, which is part of the OS itself. I'm not sure about other platforms.
I shall suggest either CORBA or any webservice library available
CORBA is a reasonable choice for you (though it may be a little bit old technology for now). I have been using CORBA for several years in my previous job.
I should say, learning curve for CORBA is kind of steep, and you need to cater a lot of extra setup, but once it it done correct, it become smooth to use. (The problem is it takes really some time to use it correctly)
Webservice is an de facto industrial standard now, and I believe C++ will have some reasonable implementation and library for that. CORBA cover more features than WS but those feature are seldom used in simple systems.