With fear of being mocked due to the simplicity I venture out to ask you are question:
What do i have to download and what do i include in my project to get going with the cURL library?
I have tried different things but all resulting in unresolved externals meaning i am including it wrong, i guess.
An explanation of the install process in whole would be awesome! I'm not quite sure exactly what files to use and where to put them. Im using visual studio 2012.
Can anyone shed some light on this?
You need to link the library during link phase of the build. There is an option in the project properties for additional library dependencies - add the .lib file(s) that comes with curl there. Just including a file in your source is rarely enough to use a library.
Ok I am using visual studio (2008) for your work but I will answer to the best of my knowledge.I am assuming you have built libcurl using .sln file or are using a prebuilt set of binaries.
First of all build a solution in project wizard and get a project in it. Right click on project and select properties
In properties go the C++ general tab, add the include directories of curl. Now go to Linker general tab and put the lib directory(which contains the dlls and obj files of your build) in the additional library directories. Now go to input option and put libcurl_imp.lib or libcurldll.a(depending upon your version and compile method). These names can be different and depend upon your build, but the extensions will be of these two types. It is the linker step in which you are making a mistake.
After this compile and run.
Related
I am quite used to Linux development and Makefiles, and started using (Windows and) Visual Studio not so long ago.
What I want to do is (I think) quite simple, but I can't seem to find how to do it using Visual Studio.
I have to write an application, which I can divide into several independent sub-parts. I want to work incrementally, and create several projects that together with a main file will end up with my full project.
What I basically want is to be able to write a small project, have a main for it so that I can fully test it, and use it as a dependency for the next project. In this case, the smaller main would be deactivated (or I can comment it), and I would just change the startup project.
If I find a bug in a subset while writing my bigger software, I could just change the startup project and solve it at a smaller scale.
Well, that's what I do all day long in Python and Java.
I tried to create new projects into my project, but I always end up having linking problems, where my main projects knows about the files in the sub projects, but not the smaller ones, etc. . .
So, is there a guide somewhere I can find to work this way ?
Thank you
For individual projects:
Every individual project property sheet has a C++ options page. Here you can specify the 'Addional Include Directories' in a comma separated form.
Similarly, there should be a property sheet for Linker where you can specify the 'Addional Include Dependencies' and the names of the libraries it depends on.
For linker dependencies of the main executable:
Go to that main project, go to its properties, go to common properties and select 'Framework and References'. This should give you a list of all the projecs that are in your solution. Keep adding them and Visual Studio should add the right linker flags automatically for you.
Sorry, have no access to the computer now else would have provided exact steps. Visual Studio can get tricky sometimes but once you use it, you'll be amazed by what it can do for you. Personally, I love it.
Hope this helps.
Thanks to Vaibhav, I was able to find a solution:
I had to :
change subproject type to lib instead of exe
Add the subprojects as project dependencies in the main project (this just sets the build order)
Comment out the main of my subprojects, to keep only one active.
Add each subproject include directory in the include repos of the main project, so that the compiler can find the header files
Add the general directory as a dependency for the linker (in this case, it is not the debug/release folder of the subprojects, but the output directory of the complete project).
Add the names of the lib files of the subprojects in additional dependencies of the linker of the main project.
To make it simple, the project dependencies capability of VS2010 just changes the order in which the projects are built. . . I miss Eclipse.
If I find a bug and want to test on of the subprojects, I have to :
change the startup project to be the subproject I want to change.
uncomment the corresponding main
change the project type to be exe instead of lib to be able to compile it.
Debug, and do everything back again to continue working on my main project.
Quite boring, don't you think ?
Looks like you trying to do manual unit testing. Use something like Google.Test. You need to make test project for every lib.
We have directory with static libs projects. Another directory with tests projects. Every test solution contains one exe project and few existing lib projects. Every project have configured dependencies. You dont need to set additional dependencies of the linker manually (paths are evil, out dir for the lib file will be taken from project settings), open project properties with right mouse button, Common properties, Add new reference and select lib project. You only need to set additional include dirs.
When you find new bug - just open test project for the library with bug, add code which cause the bug, fix it, and be happy (and sometimes run all test). And even better - use TDD.
I'm fairly new to C++ and an trying to figure out to use the TagLib library for a project I am working on. I'm working with unmanaged C++ in Visual Studio 2010 on Windows 7 64bit. I've never used an external library before so I'm very confused on how to go about this.
From this blog entry I got the libtaglib.a and taglib.dll files. I ran across this SO question on how to use TagLib, but it deals with QT Creator, not Visual Studio and I'm not knowledgeable enough about the subject to understand what is being said to translate it into what needs done for Visual Studio.
So, some questions:
Is it even possible to do this with unmanaged code?
What exactly is the function of a .a file?
Most importantly, how do I go about using the taglib.dll in my program??
I've been all over Google looking for a way to do this, but my major problem is that everything I run across is over my head. Please let me know if more info is required. Any help is very much appreciated! Thanks!
I seem to have gotten it working successfully. Here's a rough outline of what I did:
1.) I used CMake to generate the Visual Studio solution.
2.) I attempted to build the tag project in the VS solution, but it failed.
3.) I made the corrections to a few source files as outlined here: http://old.nabble.com/taglib-fails-to-compile-with-MS-VC%2B%2B-2010-td29185593.html
4.) I built the tag project again in release mode. This time it was successful.
5.) I copied the resulting dll, def, and lib files to the same directory as the source files for my project.
6.) I copied the header files from the taglib source to a subdirectory in my project (not sure if this entirely good practice)
7.) In my project settings, I set the subdirectory with the header files as an additional include directory.
8.) I added the dll, exp, and lib files to my project by just going to Add>Existing Item.
9.) I added some code from the taglib examples and built it. Everything worked so I think I got it.
One caveat I ran into, since the DLL was built in release mode, my project had to be run in release mode or it would crash. I'm guessing that if I replaced the DLL with one built in debug mode I could run my program in debug mode, but I have not tried this.
You cannot use libraries specific to GCC (you can tell because they have .a extensions) with Visual Studio. You will have to build the library from source in order to use it with MSVC. Once you have done that it's a simple matter of adding the .lib generated from the build process to your project and things should work out of the box. (Note that it's a .lib you need whether you're compiling for dynamic linking or not -- doesn't matter in msvc land)
EDIT -- after looking at TagLib itself --
In order to compile TagLib you'll need to get the CMake build system, and TagLib itself, and have CMake build you a visual studio solution. Using that solution you'll be able to build the .libs and .dlls you need. Note that because TagLib is a KDE library, you'll probably need to also build some QT bits in order for everything work work successfully. However, I don't have specific experience with the library so I'm not going to be all that helpful here.
Yo do not have to recompile the source (to create the .lib file) if you have the .dll file. With dumpbin /exports and lib (both came with Visual Studio) yo can create a lib that you can link with your application. In this link you can see a nice explanation: http://www.coderetard.com/2009/01/21/generate-a-lib-from-a-dll-with-visual-studio/
But as Billy Said, probably you would need other parts of QT to use this library.
We have a large project using VS2008 and boost 1_42. I'm trying to upgrade to VS2010 and boost 1_44. I installed VS2010 and boost 1_44 and converted the project. Now I am trying to build, and everything compiles, but fails when linking:
LINK : fatal error LNK1104: cannot open file 'libboost_thread-vc90-mt-1_42.lib'
I have changed the include and lib directories to point to the new boost 1_44 files and I have renamed the old boost 1_42 directory.
Why is the linker still looking for a vc90-1_42 file, when it is only using 1_44 headers? Is there a way that I can determine WHY the linker wants this file? The linker obviously thinks it needs the file, but why?
I have cleaned the project and I am re-building to ensure any old build files are erased.
I've run into exactly this problem a couple of times too. It's usually been some old temporary files but like in your case cleaning didn't always do the trick straight away. Does your project include any static libs that might have been built with 1.42?
Something you can try which may or may not be helpful in tracking down your issue:
Rename the old boost directory back to it's original name
Clean the solution
Under C/C++->Command Line->Additional Options add "/showIncludes"
Under Linker->Command Line->Additional Options add "/verbose:lib"
Rebuild all
Then when you build you'll be able to see at which point 1.42 headers are included, etc. in the output window. Somehow doing this helped me in tracking down where the problem was.
Along with changing the lib directory, you need to change the name of the boost library. That's in the Linker | Input section of the project settings.
Your added comment makes it clear that the dependency on the Boost 1.42 library was being created indirectly by another library that hadn't been rebuilt.
For this you basically have two choices: either add that library as a project to your main solution, and make sure it has enough dependency information that it'll be re-built when you upgrade Boost, or use the /Zl compiler switch when you build your library. This tells the compiler you're building a library so you do not want to embed library dependencies like this.
Boost uses
#pragma comment(lib)
command to inform the linker of libraries it needs to link with. It is not an error. If Boost says you need it, it's likely you do.
On How can I find out why the linker wants this file?
There are programs which will go through your app and dlls/libs and report the content of manifests and what the binaries report they depend on. You could then scan the report for the unexpected libraries being included. We used this mainly to find libs including the previous version of the VC runtime.
Have not used the one we had in about 5 years though, now if only I could remember the name of the app!
DependancyWalker (depends.exe) will allow you to see dependancies of dll/exe but not static libs.
You could open each binary as a 'file' in MSVS and look at the manifest content by hand, but I imaging this would be a bit painful. I've not tried this with a static lib.
Made a new project, added main.cpp and wrote the code at this URL:
http://www.boost.org/doc/libs/1_43_0/doc/html/boost_asio/example/echo/async_tcp_echo_server.cpp
Also, added the appropriate include path.
What's next?!?!! It seems like a darn mystery to build a boost code!
Been digging on it for more than 10 hours.
Can anyone give a straightforward answer on how to build the boost library from the code under windows, VC9?
You need to use bjam. It is responsible for creating the libraries that your application will use. Once you use bjam, you are going to need to instruct your project to include the lib file. You do this by going into the project's properties -> Configuration Properties -> Linker -> General. Add the directory which created the lib file to Additional Library Directories. You should be capable of correctly linking after that.
I believe that this link describes the steps better than I could attempt in a post
#bogertron: I want to hug you! (:
So, at last, with a real head ache, I've managed to do so.
The exact steps I took, so others will be saved from the head ache:
Went to http://www.boost.org/doc/libs/1_43_0/more/getting_started/windows.html#or-build-binaries-from-source .
Followed the "5.3.1 Get bjam" clause. Downloaded the "pre-built bjam executable for your platform" at this URL: http://sourceforge.net/project/showfiles.php?group_id=7586&package_id=72941 .
Extracted the ZIP file (my platform is Windows).
Ran "build.bat". It produced the file "bin.ntx86/bjam.exe".
Copied this file to my PATH ("...../boost_1_43_0/").
From a command line, executed "bjam.exe" and waited for about 4-5 minutes.
Then got this message at the console: "The Boost C++ Libraries were successfully built!"
That's it, it even tells you where the include & lib files are.
Not all Boost libraries are header only, Boost.System is one of them. The documentation for Boost.Asio tells you that it depends on Boost.System.
With Visual Studio, the Boost libraries use auto-linking, which means you don't have to explicitly link to the libraries you need. You however need to have the necessary libraries in the library search path, either globally or per-project.
If you don't want to build the Boost libraries yourself, you can use the installers provided by boostpro (only up to Boost 1.42 though at the moment). If you want to build them yourself instead, the documentation covers that well.
I had the same error and i followed the SourceForge. The link will take you to a folder of zipped lib and dll files for version of boost.You can download and unzip related library and when copied it to the related location everything gonna be alright ;)
In Visual Studio, right-click on your project, then go to properties and select:
Properties -> Configuration Properties -> Linker
There you add the full path of your library in the tab named "Additional Library Directories".
From the "Boost Getting Started Directions":
"5.2 Or, Simplified Build From Source
If you wish to build from source with Visual C++, you can use a simple build procedure described in this section. Open the command prompt and change your current directory to the Boost root directory. Then, type the following commands:
bootstrap
.\b2"
On Windows, I opened the Visual Studio Command Line from the start menu. First I types "bootstrap" and then I typed ".\b2".
Now with boost_1.50 the Boost.build is included in the zip file: check tools\build\v2\ or better read: ...boost_1_50_0/more/getting_started/windows.html
I am relatively new to C++ and need to use a library for the first time.
I was hoping someone would be able to show me how to properly [ link to / include ] the library.
The library I want to use is the ID3 v3.8.8 that can be found here:
http://id3lib.sourceforge.net/
I have downloaded the Windows binaries and now just need a way to link to the library.
Files downloaded: Debug/id3lib.dll, Debug/id3lib.lib, Debug/id3lib.exp, Release/id3lib.dll, Release/id3lib.lib, Release/id3lib.exp
I am using Visual Studio 2010.
Any help is greatly appreciated. Thanks in advance.
Before you can do any C++ development with this library you'll need the headers too which are in the id3lib-3.8.3.zip file. You have only downloaded the binaries which will let you run an application that needs those libraries but not re-compile it.
There are several steps, and many a pitfall. If you are a rank newbie at using C++ and VC++ in particular, every step is going to require some (gasp) reading of documentation or googling.
In VC++ 2010, use the Property Manager "C/C++ General / Additional Include Directories" section if necessary to tell the compiler how to find the header-files.
Use the Property Manager "C/C++/ Code Generation / Runtime Library" section if necessary to tell the compiler what version of the Microsoft C Runtime Library the library requires.
Use Property Manager "Linker / Input / Additional Dependencies " to specify the .lib file id3lib.lib.
Use Property Manager "Linker / General / Additional Library Directories" to tell the linker where to find .lib file.
If the dll id3lib.dll is not in the directory where you will start your program, open a Microsoft Explorer window, and right-click on "My Computer." Select "Properties/Advanced/Environment Variables", and edit the user-variable PATH to contain the path of the directory that contains the dll. Be very careful doing this. Before you change it, copy the value that's there originally and save it to a text file, in case you mess up and need to restore it. If you get it wrong, other programs can fail to start.
Good luck.
Add id3lib.lib to your project, that should satisfy the linker and the resulting executable will depend on id3lib.dll.