Building an app on Linux for Windows - c++

I am new in the programming world and I am really glad that I have finished building my first program. Its a simple C++ game that I programmed in QT on Ubuntu. Now I want to create executable files which contain all the neccessary dependencies, so the program can be ran without having QT and the used libraries.
I've been reading through questions and forum posts for the last two days, but I cant get my head around the process. I know that in order to make the program executable it has to contain all the links to the .so files or the .dll on windows, but I have no idea how to convert from .so to .dll and how to include those into my program.
I really did look at a lot of posts and all of them seemed a bit too advance. Also the whole building, releasing, packaging, deploying processes are not clear to me, but I haven't found any decent information starting from scratch.Can you point me into the right direction ?
Thanks

I can't recommend enough not cross-compiling, get a virtual machine with your target OS and install the native toolchain plus any required libraries. This is simpler, less error-prone, and issues are easier to diagnose.
There's also the massive advantage that you can test the software on the platform you're building on. Remember you'll still need access to your target OS in order to test what you have built, so in reality cross-compiling offers you no advantage.
Of course everything I've said is irrelevant if you're building for an embedded OS whose toolchain is designed for cross-compilation anyway.

Get a cross-compiler installed on your linux machine, cross-compile Qt. Then cross-compile your code so it can generate executable for windows. I think MinGW has cross compilers for linux.
Check this out How do I configure Qt for cross-compilation from Linux to Windows target?

Related

Building executables from open-source library for portability (Festival TTS)

I'm working on a Python/C++ application that will run on Mac OS and relies on the Festival Speech Synthesis System, which I'm building from source here. In my project, I use Festival's shell-based API (i.e. calling compiled executables from within my app to perform tasks). I'm having issues compiling a portable build of Festival that I can ship around to other (Mac OS) machines. My issue is specifically with absolute paths; I can compile successfully with ./configure then make, but the resulting executables reference absolute paths on my system. Obviously transferring or shipping this build to other machines results in errors since those paths don't exist.
I'm looking for a way to create portable, standalone executables of Festival (on Mac OS). Is this an issue with how I'm compiling? Is there some default switch I can run at compile time to use relative paths, or would I have to edit the makefiles myself? I notice the top-level Makefile references a variable TOP that gets reused across other make files. It's declared as TOP=. but when I search the resulting build, I see that it's resolved to an absolute path on my system.
I'm not very deft with C compilers and I have the feeling I'm missing something obvious, since this must be a common task. Any advice would be much appreciated.

Releasing a program

So I made a c++ console game. Now I'd like to "release" the game. I want to only give the .exe file and not the code. How do i go about this. I'd like to make sure it will run on all windows devices.
I used the following headers-
iostream
windows.h
MMSystem.h
conio.h
fstream
ctime
string
string.h
*I used namespace std
*i used code::blocks 13.12 with mingw
& I used the following library-
libwinmm.a
Thank you in advance
EDIT
There are many different ways of installing applications. You could go with an installer like Inno or just go with a regular ZIP file. Some programs can even be standalone by packaging all resources within the executable, but this is not an easy option to my knowledge for C++.
I suppose the most basic way is to create different builds for different architectures with static libraries and then find any other DLLs specific to that architecture and bundle it together in one folder. Supporting x86/x86-64/ARM should be enough for most purposes. I do know that LLVM/Clang and GCC should have extensive support for many architectures, and if need be, you should be able to download the source code of the libraries you use and then compile them for each architecture you plan to support as well as the compilation options you need to compile to each one.
A virtual machine can also be helpful for this cross-compilation and compatibility testing.
tldr; Get all the libraries you need in either static or dynamic (DLL) format. Check that they are of the right architecture (x86 programs/code will not run on MIPS and vice versa). Get all your resources. Get a virtual machine, and then test your program on it. Keep testing until all the dependency problems go away.
Note: when I did this, I actually had some compatibility issues with, of all things, MinGW-w64. Just a note; you may need some DLLs from MinGW, or, if you're using Cygwin, of course you need the Cygwin DLL. I don't know much about MSVC, but I would assume that even they have DLLs needed on some level if you decide to support an outdated Windows OS.

A single makeFile-Windows/Linux/Mac OS

We have some applications written in C/C++ and makefiles for the same. Currently, we are using the GNU make system on windows (cygwin based). The makefiles were written long back considering only Windows OS in mind. Now we are going to revamp everything.
I am unaware of the factors to be considered while writing the makefiles so as to make them cross platform compatible. I looked at some Sources on the Internet, but they were unsatisfactory. Can someone please list out the issues to be considered while writing the makefiles so as to make them compatible across various platforms.
PS: I have seen this link, but i think it isn't what i want.
Makefiles and cross platform development
You can use cmake - it's a cross platform tool which generates makefiles or projects files with respect to your platform. So instead of writing Makefile you write CMakeLists.txt, then you run cmake and it will generate Makefiles. When you want to compile your program on another platform you just ru-run cmake with different target project system.

Running Qt program without IDE

How can i run a program which already has been built and compiled before on Qt IDE, so that i can take that program and run on any computer I want without recompiling it on that computer. I am a beginner so bare answering this question.:)
Thanks
There are a few parts to your problem.
1) You need to compile it for each architecture you want it to be used on.
2) Each architecture will have a set of Qt dynamic libraries associated with it too that need to be available.
3) Some architectures have an easy-to-deploy mechanism. EG, on a mac you can run "macdeployqt" to get the libraries into the application directory. For nokia phones (symbian, harmattan (N9), etc) QtCreator has a deploy step that will build a package for the phone and even include an icon.
4) For systems without such a feature, like linux and windows, you'll either need to distribute the binary and require the user to have Qt available or to package up a directory/zip containing the needed Qt libraries and distribute that.
It doesn't launch because it cannot find the dependencies. As you are on Windows, these libraries can be moved in the same directory as your application. To find which library is missing, use dependency walker
I am pretty sure these libraries are not found:
The Qt dynamic libraries (can be found on Qt bin directory, take the dll)
The C dynamic libraries used for compilation. If you are on creator and use default setting it will be mingw-xxx(can be found in the Qt installation directory, don t know exactly where)
Every Architect has a set of CPU Instructions.
so it's like when you hear a language that you don't understand. like when i speak Arabic To Someone who don't Understand The Language.
Every Architect Has a set of Processor Instructions, The Compiler only convert the code into instruction only understood by The Architecture that your CPU is.
That's Why Python and the most of High level languages Use Interpreter Instead of a Compiler.
But There are some cross compilers like MinGw that Support Cross compiling To Windows (.exe files)
Simply QT Have some libraries important to be in the working directory for your project.

Moving from Windows to Ubuntu [closed]

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I used to program in Windows with Microsoft Visual C++ and I need to make some of my portable programs (written in portable C++) to be cross-platform, or at least I can release a working version of my program for both Linux and Windows.
I am total newcomer in Linux application development (and rarely use the OS itself).
So, today, I installed Ubuntu 10.04 LTS (through Wubi) and equipped Code::Blocks with the g++ compiler as my main weapon. Then I compiled my very first Hello World linux program, and I confused about the output program.
I can run my program through the "Build and Run" menu option in Code::Blocks, but when I tried to launch the compiled application externally through a File Browser (in /media/MyNTFSPartition/MyProject/bin/Release; yes, I saved it in my NTFS partition), the program didn't show up.
Why? I ran out of idea.
I need to change my Windows and Microsoft Visual Studio mindset to Linux and Code::Blocks mindset.
So I came up with these questions:
How can I execute my compiled linux programs externally (outside IDE)?
In Windows, I simply run the generated executable (.exe) file
How can I distribute my linux application?
In Windows, I simply distribute the executable files with the corresponding DLL files (if any)
What is the equivalent of LIBs (static library) and DLLs (dynamic library) in linux and how to use them?
In Windows/Visual Studio, I simply add the required libraries to the Additional Dependencies in the Project Settings, and my program will automatically link with the required static library(-ies)/DLLs.
Is it possible to use the "binary form" of a C++ library (if provided) so that I wouldn't need to recompile the entire library source code?
In Windows, yes. Sometimes precompiled *.lib files are provided.
If I want to create a wxWidgets application in Linux, which package should I pick for Ubuntu? wxGTK or wxX11? Can I run wxGTK program under X11?
In Windows, I use wxMSW, Of course.
If question no. 4 is answered possible, are precompiled wxX11/wxGTK library exists out there? Haven't tried deep google search.
In Windows, there is a project called "wxPack" (http://wxpack.sourceforge.net/) that saves a lot of my time.
Sorry for asking many questions, but I am really confused on these linux development fundamentals.
Any kind of help would be appreciated =)
Thanks.
How can I execute my compiled linux
programs externally (outside IDE)? In
Windows, I simply run the generated
executable (.exe) file
On Linux you do the same. The only difference is that on Linux the current directory is by default not in PATH, so typically you do:
./myapp
If you add current dir to the path
PATH=".:$PATH"
then windows-like way
myapp
will do, but this is not recommended due to security risks, at least in shared environments (you don't want to run /tmp/ls left by somebody).
How can I distribute my linux application?
In Windows, I simply distribute the executable files with the corresponding DLL files (if any)
If you are serious about distributing, you should probably learn about .deb (Ubuntu, Debian) and .rpm (RedHat, CentOS, SUSE). Those are "packages" which make it easy for the user to install the application using distribution-specific way.
There are also a few installer projects which work similarly to windows installer generators, but I recommend studying the former path first.
What is the equivalent of LIBs (static library) and DLLs (dynamic library) in linux and how to use them?
.a (static) and .so (dynamic). You use them in more or less the same way as on Windows, of course using gcc-specific compilation options. I don't use Code::Blocks so I don't know how their dialogs look like, in the end it is about adding -llibrary to the linking options (guess what: on windows it is about adding /llibrary ;-))
Is it possible to use the "binary form" of a C++ library (if provided) so that I wouldn't need to recompile the entire library source code?
Yes. And plenty of libraries are already present in distributions.
Note also that if you use .deb's and .rpm's for distribution, you can say "my app needs such and such libraries installed" and they will be installed from the distribution archives. And this is recommended way, in general you should NOT distribute your copy of the libraries.
If I want to create a wxWidgets application in Linux, which package should I pick for Ubuntu? wxGTK or wxX11? Can I run wxGTK program under X11?
Try wxGTK first, dialogs may look better, gnome themes should be used etc.
If question no. 4 is answered possible, are precompiled wxX11/wxGTK library exists out there? Haven't tried deep google search.
Try
apt-cache search wx
(or spawn your Ubuntu Software Center and search for wx)
In short: you will find everything you need in distribution archives.
Navigate to the folder with your compiled program and execute ./program
Send the program, plus any .so files
.a is static library, .so is shared libraries.
Yes, but often you need to compile it yourself first.
Not sure about wxWidgets distributions, though.
Since Ubuntu comes with wxGTK packages you should definitely build against them. For development you should use a debug version though, so it might be good to build yourself, but for deployment building against the packages the system provides seems better.
wxX11 is a worse choice than wxGTK, use it only for systems where wxGTK doesn't exist or requires newer GTK libraries than are available.
Why not just stick with what you know and develop in .NET? Ubuntu comes native with Mono. You could keep using Visual C++ or step up to C# and make your life a whole lot easier.
A piece of general advice to Linux newcomers, but who are technically minded to begin with, is: You should learn to use your chosen distribution properly.
In your case, that means learning how to acquire the right development packages provided by Ubuntu. For instance, some other people are advising you to download the source for libraries you are going to use, but the better way is to use Ubuntu's package system to download the libraries you want to program against, together with the headers for that library (often put in a separate package) as well as the debug symbols for the library (also often in a separate package).
Look in the System->Administration menu in Ubuntu for the Synaptic tool, which allows you to search the package repositories on the Internet. You'll almost certainly find packages for the libraries you need, as well as all tools.
1, Unix generally doesn't have a particular extension for an executable - so myprog.exe would just be myprog.
You might have to set it to be executable if the IDE doesn't do this automatically, type "chmod +x myprog"
5, For wxWindows I would download the source and build it, check the build instructions but it's probably just a matter of "configure;make;make install". Generally in Unix you build libs form source so that they can correctly find all the components on your machine - you also have the source of examples etc.
I just added some information to rlbond's answer.
It is depens on Linux version. If you use a Ubuntu - create a deb-package. (http://ubuntuforums.org/showthread.php?t=51003)
Can I run wxGTK program under X11?
Yes, if you have wxGTK package installed :)
This is not really going to answer your questions, but I think is a valid recommendation.
You have two issues you are trying to deal with:
The Linux environment.
Making sure your program is
portable.
If I were you I would load CodeBlocks on Windows and run against either Cygwin or Mingw, that will help you make sure your code is portable across platforms. You are familiar with the environment and would gain maximum productivity getting over the OS hurdle.
Once you are satisfied with the above then take your code and move it to Linux. At that point any porting effort should be trivial.
When you say your program didn't show up I assume you mean that it was there in the file browser but when you double clicked it you got a busy cursor for a moment and then nothing happened?
If so then it means that the program failed to run, probably because it couldn't find the dynamic libraries it's linked against. To diagnose the problem you can run it from a terminal and then you'll be told what the problem is.
You might want to read the manual page for ld.so i.e. type
man ld.so
into a terminal. This tells you where the Linux dynamic library linker looks for libraries at run-time. It also refers you to another useful tool called ldd which I recommend becoming familiar with if your are doing Linux development.