How could I write a program which runs on both Windows 7, Mac OS X (and maybe linux too)?
I heard Qt are a great framework to build cross-platform GUIs, but I think every program version need a recompile, isn't that right? And should I compile the win version under windows, the mac version under mac os x, the linux version under linux and so on?
I'm getting ideas and/or suggestions
The underlying binary format is different on each platform, so unless you're using a virtual machine (like Java or Flash does) you will have to recompile your program on each platform.
Some compilers (like GCC) allow cross-compiling, but it is not trivial to set up. Probably the easiest system to cross-compile on is Linux (there are several open source projects that have cross compilation set up from Linux to Windows).
In case of a GUI application, it depends on the language -- if you're stuck with C++, Qt or wxWindows might be a reasonable choice providing an abstraction layer over the native windowing system.
If you can go with Java, it makes life simpler, however the windowing system is Java's and not native.
Another language to think about is FreePascal w/ Lazarus -- it has a pretty good GUI designer that compiles to the native windowing system on every platform (WinAPI on Windows, Cocoa on OSX and GTK on Linux).
Not sure if C++ is a must, but Adobe Air is a great cross platform development environment for desktop, and its growing for mobile development as well. If you need an example of a major application using Adobe Air to deploy to multiple desktop OSes, just check out tweetdeck http://www.tweetdeck.com/
I'd highly suggest also looking into Flex and Flash Builder if you go that route.
There are two separate issues I would highlight when writing cross-platform programs -- how to make your code portable, and how to arrange for it to be built on the various different platforms.
As far as the building side of things goes, I would look into a cross-platform build system like CMake (http://www.cmake.org). You essentially write a script and CMake will generate the appropriate project file/makefile for a specific platform. You then build your program on each platform as you would normally. For example, on Windows, you might use CMake to generate a Visual C++ project for you, and then use Visual C++ to actually build your executable. On Linux, you might use CMake to generate a makefile, and then build the executable using g++.
The other aspect is how to make your code portable -- the key is to write C++ standard-compliant code and make use of libraries that are themselves portable across the platforms you're interested in. You can (and may sometimes need to) write platform-specific code for each of the different platforms -- if you do, you should hide it behind a portable interface and have the rest of the code use that.
Yes, you need to compile for each version when using C++.
The only thing that prevents you from compiling a program, for example, for Windows on Mac is to get a tool for doing that. It is possible, but the problem is finding the toolset.
Also you can use a virtual machine for running diferent OSs and compiling code for all platforms on the same machine.
Java runs on Windows, OS X and Linux
Related
I use the Dev-Cpp program with the MinGW compiler that allows you to compile C / C ++ code to obtain a Windows launcher, but is there a compiler for Windows that allows you to create executables for Linux?
You can install Windows Subsystem for Linux, or set up a VM and do it that way.
Or as #user4581301 mentioned, use a cross-compiler.
http://metamod-p.sourceforge.net/cross-compiling.on.windows.for.linux.html
Ignoring the fact that Dev-C++ has been obsolete for nearly a decade (I may have an unpopular opinion however that you should use whatever tools you can to learn whatever you can, even if that means using 'obsolete software' [as long as it's purely for learning and not production use])...
You have a couple options, one of which has been mentioned by somebody. 1.) Use a cross-compiler, and 2.) (which I personally would recommend, if it is viable for your particular needs) simply compile on actual Linux.
To do this, you just need a working distribution of Linux with a development environment. You can use a virtual machine, Windows Subsystem for Linux (WSL), or a physical machine with Linux running on it.
From there, if you want the code to compile for multiple operating systems, you'll have to make sure your libraries and frameworks and other OS-specific code (e.g., filesystem paths, system calls) are properly handled, or just use cross-platform libraries. If you're dealing with standard C/C++, then this won't be of any concern.
Since Dev-C++ uses MinGW (the Windows port of GCC), then the actual compilation process should be the same, although on Linux IDEs are not commonly used, so you may have to get your hands dirty with shell commands, but that's not too hard once you get started. Good luck!
I am working on a C, project which uses ffmpeg library.
Currently I'm working on windows platform, and I'll be cross compiling the project for Linux ARM.
With that background, I have few basic questions.
If I use ANSI C++, I can be sure that, I'll be able to cross compile the project using corresponding compilers [ MSVC, MingW ]
But ..
If I'm using "Win32" and other "Windows" specific APIs in my project, how does the cross compiler will handle it, to make the project able to run on Linux.
Similarly, If I'm using Linux specific "features" in my project, how does the cross compiler will handle it, to make the project able to run on Windows.
When you cross-compile, the code that is being cross-compiled must use APIs that are available on the target platform (ie, the one that it will eventually run on). A cross-compiler does not magically give access to Win32 APIs when its output is run on a Linux machine; it is the same as compiling the code on the target machine, but means you don't need to actually do so. You could achieve the same thing, in other words, by just running a native (non-cross) compiler on an ARM Linux box, but you'd need a powerful enough ARM box to run the compiler.
That said, in principle, you could cross-compile to Linux while using winelib to provide win32 APIs. Not sure how well it works on ARM though - it's only really meant to be used on x86.
Finally, note that cross-compiling tends to be quite complex even in the best of times. It may make your life simpler to cross-compile from x86 Linux to ARM Linux instead of x86 Windows to ARM Linux - while it's possible to do cross-OS and cross-platform builds, the less variables you have changing the simpler things will be.
If you use Winapi, your project will not be able to run on Linux.
I have a C++ eclipse project that I would like to easily compile In Windows and OSX.
The project is currently using an automatically generated makefile.
The libraries that I need vary depending on the platform.
In osx I'm using the CoreMidi, CoreAudio, and CoreFoundation frameworks.
In Windows I'm using the winmm.lib and multithreaded libraries.
What's the simplest way to link different libraries/frameworks depending on the current platform?
I'm currently using the gcc toolchain on OSX. Should I start using the cross compile toolchain?
Should I have two projects. One for working in windows, and one for osx, checking them both in to version control?
Should I write a custom makefile instead of using the automatically generated option that has different g++ arguments depending on the platform?
I personally had the same goal for a project and came to the conclusion the Qt framework was the best thing for me. It handles multiple languages, unicode strings, XML, network communications, native looking user interfaces, console applications: it can do an AWFUL lot.
However, as Paul pointed out, you really have to plan it from the start.
Qt does a good job of abstracting the platform away (in a module called QtCore) allowing you to write vanilla C++ code, or you can chose to include some Qt C++ language extensions which a Qt helper application called the moc (meta object compiler) creates vanilla C++ from, which can then be compiled by most common C++ compilers.
It also has a nifty cross-platform makefile generator called qmake which works on project files to create normal make files for the platform its running on.
Off the top of my head at least Windows XP & 7, OSX 10.4, 10.5, 10.6 are supported currently. But note that OSX Lion is (as of writing) not officially supported but I suspect it will be in the next release.
Based on your description, I am not sure you can easily make it cross-platform. Even without using third-party library, you have to provide separate code for osx and windows. Most of time, they design the system as cross-platform first. It's really hard to make an existing project on single-platform to cross-one. If you have the cross-platform requirement, you'd better design in that way first and rewrite from scratch.
Even though Eclipse can run fine on both OS X and Windows, it is not designed to be used in this way.
The best way to do it is to use separate IDE projects for each platform. This this is the easiest way to have unique compilation settings for multiple platforms.
Yes, you can use two eclipse projects. Alternatively, it's not unusual to have a X-Code project for OSX, and a Visual Studio Project for MS Windows.
I have a question about writing programs to be portable between windows and linux.
Recently I have realized that if you write a program that uses any sort of external library, if that library doesn't have a linux version (or a windows version when developing in linux) then you're screwed.
Here then is my question: if I write a program in linux that links to lol.a and then I want to compile and run it on windows without recompiling lol.a into lol.lib, can something like MinGW or Cygwin do this? Link to .a files on a Windows platform to result in an .exe file that can Windows can run?
you will have to recompile all libraries for different operating systems. The binary formats for libraries vary from operating system to operating system. More importantly, even if you aren't using libraries, you need to recompile for the simple reason that the different operating systems have different syscall conventions. The only way to get around this is with a virtualizer.
In particular, CygWin cannot run linux programs. at all. CygWin provides only a posix compatibility layer between your program and the Windows kernel.
The situation is a bit less bleak on linux. Wine can run some native windows code (without the need to recompile anything, including your original code). But Wine also has limitations. It is not a complete Windows API, and anything that the library code requires to run must be available on Wine, or else it won't work either. For many, simple apps, this isn't a major problem, but many newer Windows API's, some dark corners of older ones that don't see much use, and in particular, anything that is hardware specific, probably won't be available.
If you intend to run on multiple platforms, it is urgent that you first verify that the libraries you intend to use are also cross platform, or that there are reasonable equivalents for all of the operating systems you wish to use.
No, Cygwin provides (partial) source portability for *ix programs. Of course, there are higher level toolkits that also provide source portability, like QT and GTK. Either way, you still have to recompile the program and library. For binary portability, you'd need essentially the opposite of wine, a program that understood ELF and mapped Linux system and library calls to Windows ones. As far as I know, that doesn't exist.
No. You have to build it separately for Windows or Linux.
There are couple of suggestions given your situation:
Develop the entire code for Windows, compile and run it.
On Linux, use the WINE emulator http://www.winehq.org/download/
If you choose to develop the code in Linux, look into Windows SFU http://en.wikipedia.org/wiki/Microsoft_Windows_Services_for_UNIX
If possible post us what kind of s/w you are trying to develop -- 3rd party libraries like boost [http://www.boost.org] have a whole host of functionality that is platform independent. You definitely want to check out the options that boost gives you. Also check out other open source sites like github etc.
Don't get into the habit of using platform specific libraries. I know they make life easier at times, but that is more than compensated when you need the code on a different platform.
is there any development environments that allow you to have one code base that can compile to Linux, Mac OS, and Windows versions without much tweaking? I know this is like asking for where the Holy Grail is burred, but maybe such a thing exists. Thanks.
This is achieved through a number of mechanisms, the most prominent being build systems and specific versions of code for certain systems. What you do is write your code such that, if it requires an operating system API, it calls a specific function. By example, I might use MyThreadFunction(). Now, when I build under Linux I get a linux specific version of this MyThreadFunction() that calls pthread_create() whereas the windows version calls CreateThread(). The appropriate includes are also included in these specific platform-files.
The other thing to do is to use libraries that provide consistent interfaces across platforms. wxWidgets is one such platform for writing desktop apps, as is Qt and GTK+ for that matter. Any libraries you use it is worth trying to find a cross-platform implementation. Someone will undoubtedly mention Boost at some point here. The other system I know if is the Apache Portable Runtime (APR) that provides a whole array of things to allow httpd to run on Windows/Linux/Mac.
This way, your core code-base is platform-agnostic - your build system includes the system specific bits and your code base links them together.
Now, can you do this from one desktop? I know you can compile for Windows from Linux and so probably for Mac OS X from Linux, but I doubt if you can do it from Windows-Linux. In any case, you need to test what you've built on each platform so my advice would be to run virtual machines (see vmware/virtualbox).
Finally, editors/environments: use whatever suits you. I use either Eclipse/GVim on Linux and Visual Studio on Windows - VS is my "Windows build system".
Maybe something like CodeBlocks?
Qt is a good library/API/framework for doing this in C++, and Qt Creator is a very pleasant IDE for it.
I've heard this is possible. Your compiler would need to support this. The only one that I know that does is GCC but it obviously requires a special configuration. I, however, have never used this feature. I've only seen that it exists.
What you are looking for is called "Cross Compiling"