I intend to put/get file to/from an iRODS server. iRODS provides well documented JAVA and PHP APIs, however I'm looking for a C/C++ library providing such functions.
Are there libraries or examples of code I could use ?
Not exactly what you've requested, but you might be interested in Baton, which uses the iRODS C API, and has had a lot of work put into it, so you might be able to use it as-is, depending on your use case, rather than writing your own from scratch. Failing that, it provides a lot of examples of using the API.
If you have reasons that you must write your own, then in 4.x the the iRODS docs for the C API are much improved from the earlier 3.3.1 code path.
Good luck and do try the mailing list as a previous commenter mentioned - the developers respond often.
Related
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.
Is there a good, simple library which allows C++ to load a webpage? I just want to grab the source as text. I'm not using any IDE or significant library, just straight command line.
Tangentially, is there something fundamental I'm missing about programming in C++? I would think any language in common use today would have droves of web-based functionality, being so central to computer usage, but I can find next to no discussion on how to accomplish it. I realise C++ significantly predates the modern internet, so it lacking any core ability in the regard is reasonable, but the fact that relevant libraries seem so sparse is baffling.
Thanks for your help.
Sure, for example libcurl is powerful and popular.
Internet-related libraries for C++ are extremely abundant -- they're just not part of the C++ standard, partly because the current version of that standard is so old, though I'm sure that's not the only reason. But turn to the world of open sources and you'll find more than you can shake a stick at.
libcurl is a popular C library for fetching HTTP and other URLs. There's also cURLpp a C++ binding .
On Windows you have the WinINet and WinHTTP APIs.
I think HTTP is a bit too complex to be part of the C++ Standard Library. The specification would have to take a lot of details into account such as proxy servers and MIME types.
I know that a lot of c/c++ XML library questions have been asked already (I tried to read through all of them before getting to this).
Here are the things I'm going to need in my own project:
Excellent performance
SAX2
Validation
Open source
Cross platform
I was going to use Xerces-C, but I see that a simple SAX2 setup with nothing going on in the filter is taking 5 seconds to run. (Perhaps I'm doing something wrong here?)
I would like to use libxml++, but as I tried to get it set up on my MacBook, there were some crazy dependencies that took me all the way back to gtk-doc, at which point I sort of tabled the idea.
So now I'm at libxml2. Is this the way to go? Have I missed an important option, bearing in mind the five requirements above? I don't mind using a (good) c-library like libxml2, but a c++ interface would be nice. (I don't like Xerces-C's API very much.)
I am willing to bend on the SAX2 requirement if comparable functionality is available.
Having spent a goodly amount of time on this same problem, it was my conclusion that libxml2 is the best option available under your guidelines. The C interface is not too difficult to use and it's very fast.
There are some other good options for commercial libraries, but most of the other comparable open-source options are either painfully slow or are mired in a deep, annoying vat of dependency soup.
You say you need these things in your project, but don't give any idea of the pipeline. For example, we had a whole load of static XML files which needed to be loaded quickly, but only validated rarely. So validated using a separate process in batch (using RelaxNG as it was human writable markup ) and loaded the XML using expat. The system also used XMPP, so checked streaming input, but that didn't require validating against a schema (partly because it was streamed, and mostly because most of the possible errors were not expressible in a schema).
If you need a whole host of other facilities, you can consider Qt, which has good XML support. Be warned though, it's WAY more than an XML processing library; it's a full blown application framework with support for GUIs, networking and a whole host of other things.
Qt
You can also try Poco. It's another application framework, but not as huge as Qt (i.e. no GUI-related things etc.)
Poco
Lastly, if you don't mind a C library, you can use Expat. It's not SAX per se, but writing code using Expat is somewhat like SAX. It has C++ wrappers, but they're not officially part of the project IIRC, and may not be as well-maintained or designed. I'm not too sure though.
Expat
Hope this helps!
EDIT: I misread your original post: not too sure about the validation features of these libraries, I've never used them before.
I'm looking to add full text indexing to a Linux desktop application written in C++. I am thinking that the easiest way to do this would be to call an existing library or utility. This article reviews various open source utilities available for the Gnome and KDE desktops; metatracker, recoll and stigi are all written in C++ so they each seem reasonable. But I cannot find any notable documentation on how to use them as libraries or through an API. I could, instead, use something like Clucene or Xapian, which are generic full text indexing libraries. They seem more straightforward but if I used them, I'd have to implement my own indexing daemon, an unappealing prospect.
Also, Xesam seems to be the latest thing, does anyone have any evidence that it works?
So, does anyone have experience using any of the applications or libraries? How did you use it and what documentation was useful?
I used CLucene, which you mentioned (and also Lucene.NET), and found it to be pretty good.
There's also Strigi which AFAIK works with Xesam and is the default used in KDE.
After further looking around, I found and worked with Recol. It believe that it has the best C++ interface to a full text search engine, in this case Xapian.
It is important to realize that clucene and Xapian are both highly complex libraries designed primarily for multi-user server applications. Cutting them down to a level appropriate for a client-system is not easy. If I remember correctly, Strigi has a complex, pure C interface which isn't adapted.
Clucene also doesn't seem to be that actively maintained currently and Xapian seems to be maintained. But the thing is the existence of recol, which allows you to index particular files without the massive, massive setup that raw Xapian or clucene requires - creating your own "stemming" set is not normally desirable, etc.
I need to use XmlRpc in C++ on a Windows platform. Despite the fact that my friends assure me that XmlRpc is a "widely available standard technology", there are not many libraries available for it. In fact I only found one library to do this on Windows, (plus another one that claims "you'll have to do a lot of work to get this to compile on Windows). The library I found was Chris Morley's "XmlRpc++". However, it doesn't have support for SSL.
My question therefore is: what library should I be using?
I've written my own C++ library. It's available at sourceforge:
xmlrpcc4win
The reason I wrote it rather than using Chris Morley's was that:
The Windows "wininet.lib" library gives you all the functionality for handling Http requests, so I'd rather use that. As a result, I only needed 1700 LOC.
"wininet.lib", and therefore my implementation, supports HTTPS
Chris Morley's use of STL containers was quite inefficient (Chris, mail me if you read this).
Until I wrote my own library, (see above) here was my answer:
Currently, the XmlRpc++ library by Chris Morley is the only public domain/LPGL XmlRpc implementation for C++ on Windows.
There are a couple of C++ implementations for Linux, either of which could be presumably easily ported to Windows, but the fact seems to be that no-one has yet done so and made it publicly available. Also, as eczamy says, "The XML-RPC specification is somewhat simple and it would not be difficult to implement your own XML-RPC client."
I'm using Chris Morley's library successfully, despite having had to find and fix quite a number of bugs. The Help Forum for this project seems to be somewhat active, but no-one has fixed these bugs and done a new release. I have been in correspondence with Chris Morley and he has vague hopes to do a new release, and he has contributed to this stackOverflow question (see below/above) and he claims to have fixed most of the bugs, but so far he has not made a release that fixes the many bugs. The last release was in 2003.
It is disappointing to me that a supposed widely supported (and simple!) protocol has such poor support on Windows + C++. Please can someone reading this page pick up the baton and e.g. take over XmlRpc++ or properly port one of the Linux implementations.
There are dozens of implementations of the XML-RPC implementations, some in C++, but most in other languages. For example, besides XmlRpc++ there is also XML-RPC for C and C++. Here is a HOWTO on how the XML-RPC for C and C++ library can be used.
The XML-RPC specification is somewhat simple and it would not be difficult to implement your own XML-RPC client. Not to mention, it would also be possible to take an existing XML-RPC implementation in C and bring into your C++ project.
The XML-RPC home page also provides a lot of useful information.
Just wanted to note a couple of items:
The source in the cvs repository for XmlRpc++ has support for OpenSSL (although I have not tried it, it was contributed by another developer).
Most of the reported bugs are fixed in cvs; I don't have access to a linux machine at the moment, so I haven't made an official release.
XmlRpc++ is not public domain. It is copyrighted and licensed (LGPL).
Thanks,
Chris Morley
I was able to get Tim's version of xml rpc working with https and with basic username / password authentication.
For the authentication:
1) the username and password need to be passed to the InternetConnect(...) function
2) an http request header of "Authorization: Basic base64encoded(user:pass)" needs to be added prior to sending the HttpSendRequest(...) command.