Can i use windows libraries in linux and vice versa? - jpeg

As per my knowledge, windows uses .lib and .dll extension for libraries and linux uses .a and .so. I am working on a project in ubuntu for manipulation with jpeg image files. so i want to know if these libraries can be used interchangeably in linux and windows? for example if have created example.so library in ubuntu and now i want to use it in some compiler in windows...

If you're planning on running under Wine, then yes.
Otherwise the chances are small. Windows DLLs will most probably use Windows APIs not available on Linux. Even if they're not the DLLs are built for use with compilers running on Windows.
Why not use imagemagick? http://www.imagemagick.org/script/index.php

Related

Running Qt application built for Linux, on windows

I have a Qt application which I built on Linux. I would like to run the same application on Windows. Is it possible? If yes, how? The Qt application software that I downloaded and used, is version 4.7.4.
Is it possible? If yes, how?
Yes, it is possible if the application is cross-compiled for Windows target on Linux.
You would need to have the mingw compiler installed on the Linux box when building the application for Windows. You would also need to make sure to use the proper `-mkspec- option for qmake.
If this is missed while building the application on Linux, it is probably not cross-compiling, so you would not be able to run the code on Windows off-hand unless you have a virtual machine installed for Linux, in which case you could do it, for sure.
You can install a Windows alongside your Linux and install VS2010 and Qt 4.8.* libraries for windows and compile your project there. You may need to make some changes to your source code in order to be compatible with Qt 4.8.* .

Can I compile and run a linux app C++ source on Windows?

I have source code for a linux application. It seems I can compile it on windows with CygWin. My question is, after compilation, can I run it on Windows?
Depends totally on what APIs you use. If you stick to C standard library things, like <stdio.h>, <stdlib.h>, etc. then yes, you can just compile and run on either OS. Or for C++ apps, there is the Standard C++ Library, which any OS / development environment should provide.
If you use any OS-specific APIs, then of course it will not be compatible with another OS. There are libraries however, like APR that try to abstract out the OS-specific bits.
From a casual glance at the code you've linked to, it appears to not use any OS-specific APIs. However:
Note that this code requires the Gnu Scientific Library, http://www.gnu.org/software/gsl/
you'll need to get that library installed as well.
The simple answer is yes; if you can compile a Linux application with Cygwin, then the compiled application will run on windows. Cygwin provides windows implementations of many unix system functions and libraries.
Cygwin/mingw(http://www.mingw.org/) should have most of the tools you need to build the binary. Once the build succeeds, you can run the binary (only) on windows.

Deploy a Qt Application Binary on Linux, compatible with LSB

I have developed a small application in Qt Creator on Ubuntu 12.04 which I want should run on any other linux distro (mostly different versions of CentOS and ubuntu), just like any portable application on windows does.
I want to be able to simply share the binary file of the Application, and run the application.
I am able to successfully do this in windows, by just building the project in QT Creator and then putting the required libraries in the Application directory and then transfering them to other windows systems.
I searched all over and found out that I should be trying to build the project using LSB(Linux Standard Base) Compatibility, so that it runs on other linux distros. Is that the right way to do this?
I am very new to Qt and also to Linux (dont know much of Shell Scripting).
Thus, I dont know how I should proceed to make the Application LSB Compliant.
I have refered to, the following links:
Distributing Qt-based binaries on Linux and
Deploying Qt applications on Linux but have not beem able to understand what I am suposed to do.
I also found this question here which states a very similar situation as mine, but because I am a novice, I dont know how I should do this.
Moreover, considering that the first two articles were written 6 years back, shouldn't there be a simpler way to deploy Qt apps on the linux platform now?
I also saw something about static linking, is that the way to go?
Isn't there a way by which all of this can be done through Qt Creator itself?
If there is no hope of creating a portable Qt Application for Linux, then is there a way, say a shell script or something that would combine all the steps required to compile the Qt project on another computer and run it. Say, download Qt-SDK if not present, run qmake and make and then the newly compiled application, if not already there, so that the user can run the program just by running one script.
Your problem here is not the Linux Standard Base, but rather the presence or not of the specific version of Qt you need (or a later one).
Exactly like on a Windows machine, a user may have any of Qt installed, or they may not have it at all. On Windows it is easier to check for the presence of a certain version of Qt than it is on Linux, thus it is easier to write install tools that automate the experience.
To solve your problem there are a few ways:
Inform the user that your program requires a certain version of Qt or higher, and let the user handle the problem
Learn how to create packages for every distribution you want to target and create specific packages
Use a program like 0Install or Elf Statifier to create a package/executable containing all the necessary libraries.
The latter is similar to what many Windows and Mac programs do (they include every library they need within the installer), but it is not the preferred way on Linux, which relies heavily on shared libraries.
Making a binary application compatible with any other Linux distro is practically impossible since you will never know in advance which libraries are available in distro X, or what version of that library is available. Even among a single distro (e.g. Ubuntu), binary application are almost never backward-compatible, since anything built on Ubuntu 12.04 will have dependencies on versions libraries which are installed on that version of Ubuntu, and trying to run that binary on Ubuntu 10.04 will most probably fail simply because it doesn't have a recent enough version of glibc or some other necessary library.
However, the idea can be much more implementable if you limit yourself to a finite list of distros and versions of those distros. You can then know which libraries are available for those distros, and aim for the lowest common denominator. I used to maintain a binary application which had to support several distros (Ubuntu, Fedora, OpenSUSE, SLED, Mandriva), and the way I would do it is install the oldest distro I was targeting on my build machine. That way, the binary application would be linked to the oldest versions of the libraries available on those distros. Unless there's a new major version of such a library (which happens quite rarely, and even then, distros usually distribute the previous major version for a while for compatibility purposes), your compiled binary will then be compatible with all your targeted distros.
Therefore, the quick piece of advice I would give for your situation, use the oldest LTS version of Ubuntu which is still supported (10.04 at the moment) for your development, and you should be pretty safe for most recent popular distros. For the application you already developped on Ubuntu 12.04, you should have no problem simply recompiling the same source on 10.04. Understand that you will never however achieve 100% compatibility with a compiled C++ Qt application.
If Qt is not all that important to you, you could use a higher-level or interpreted language such as Python, Java, Perl or Ruby. With such languages, you can usually count on the language implementation already being installed on the target distro.
Deploy an application in Linux is a nightmare, luckily there are some solutions. Check this projects to build a portable binary with all their dependencies bundled:
http://statifier.sourceforge.net/statifier/main.html
http://www.magicermine.com/index.html
http://www.pgbovine.net/cde.html
Another solution is make a portable 0install package:
http://0install.net/
I recomend this solution. Personally I have been problems with the 3 first packagers.

NSIS support for Linux and Solaris

Does NSIS support Linux and Solaris? I read somewhere that we can compile nsis script on Linux but cant execute the .exe generated on any other platforms but Windows. Can somebody put more light in this?
No.
See the NSIS feature list for more information ...
Portable Compiler
The NSIS compiler can be compiled for POSIX platforms like
Linux and *BSD. Generated installer
will still run on Windows only, but
this way they can be generated without
Windows or WINE.
You can compile installers on POSIX and Windows systems, but it always produces a Win32 PE file that only runs on Windows (And maybe under WINE on *nix)
Check the NSIS manual for more info
The installer systems for Windows and Linux are completely different.
Whereas Windows' only contribution to a software management system is one registry entry pointing to the uninstaller, Linux has a full working software management system. There are apt, yum, pacman and many more out there, which are supporting many more features and possibilities including automatic execution of scripts and pulling in/installing dependencies. If you have a cross platform application you wanna share, you're either stuck with creating a tar-ball, or you learn how to build deb/rpm etc. packages.
Linux and Windows are not binary compatible, so you can't do that.
But, most of the windows binary installer could able to install at WINE

anyway to write dlls in linux?

Is there anyway to write dlls in linux?
Do I have to install windows to write dlls in linux? Right now one of my courses requires me to write a dll for this.
You should take a look into 'shared libraries'
http://www.linux.org/docs/ldp/howto/Program-Library-HOWTO/shared-libraries.html
Lots of folks are getting near the right answer but not providing it: gcc can generate win32 PE/COFF files without problem, and of course can always build as a cross compiler on any platform it can target. The binutils port targets windows .exe and .dll files natively, and there's a "dlltool" utility for handling the edge cases where Unix and Windows linkage metaphors are different.
Additionally, the "mingw32" project provides a set of link libraries and header files for building C applications against the win32 API. These likewise install just fine on any Unix.
Here's a site I turned up after a quick google with instructions for building the toolchain.
Not really. Building any kind of executable intended for OS "A" while using OS "B" is a process commonly known as cross-compilation. In this partciluar case, you would need a cross-compiler running on Linux, but targetting Windows. I don't know any vendor selling such a product.

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