I would like to know is openssl and curl are a part of android core .. becoz I have seen in many forums where users are trying build the openssl and curl for android ndk and use in there ..
Why do users go with their own build?
Android comes with /system/lib/libssl.so and /system/lib/libcrypto.so, which are ported from www.openssl.org. For example, the 4.0r1 (ICS) build includes version 1.0.0e. These libraries may not expose all the features of OpenSSL, though.
As for curl, look in Using cURL in Android for references.
They're not. On the other hand, both cryptographic primitives in the scope of OpenSSL and an HTTP stack are a part of Android API on the Java side.
Why do folks roll their own? Probably to migrate legacy C/C++ code, rather than rewrite into reflected Java calls. Those are ugly.
Related
The Android app I am working on is completely written in C++. I need to integrate it with a static library that also is written in C++. There is no dependency on STL in any of the projects.
The static library uses cmake to build. Unfortunately, the app is based on an old AOSP version of Android NDK and has no support for cmake.
I also have a newer version of Android NDK in a different directory. This version does support cmake toolchains.
I am thinking I will build the static library against the new NDK and use it in my main project. The ABI is the same for both the projects - armv7a.
I have tested this logic with a sample code. It seems to work. I am able to invoke methods in the static library from my main app.
Also, there are no name-mangling issues.
The question I have is if there is any issue I am overlooking.
I am thinking it should not matter that the compilers used to build the sources are different. As long as they are producing arm-compatible code, I should be able to able to integrate them.
As a matter of fact, another library that I am using, gstreamer, is available for download as pre-built binaries at https://gstreamer.freedesktop.org/data/pkg/android.
Please advice.
For those interested, mixing NDKs doesn't seem to be an issue as long as you follow certain guidelines. Some of them are listed at https://developer.android.com/ndk/guides/cpp-support.
Essentially, there is no problem if your project is 'C' based. However, if you are using C++, you must not use STL.
I have managed to build part of my code with two NDKs and I am not seeing any link time or runtime errors.
I have developed a .NET 4.5 application using WinForms. I want my application to run not only on Windows, but also on Linux, so I decided to port it to Mono.
However, I can't find any information on how to use Visual Studio for Mono. I don't want to switch to MonoDevelop, since VS provides much of the functionality I want and I am already familiar with it.
There apparently used to be something called Mono Tools for Visual Studio, which David Lively insists works on current VS editions, but I don't want to run an extension that was deprecated 3 years ago. I don't even know where to download the extension - it redirects to Xamarin, and Xamarin seems like not what I want because while it mentions VS integration, it forces me to install a bunch of Android and Java SDKs (why?).
As far as I can see, .NET and Mono code looks fairly similar, and there are 3 main concerns:
Making VS use the Mono compiler instead of the C# compiler, so I can tell if non-Windows users can compile my source, and also get notified about missing libraries
Making IntelliSense suggest only Mono-supported things
Making the "Run" command run the application using Mono, not .NET, so I can test it correctly
Is there really no easy way of accomplishing these?
Note: I want to develop Windows and Linux desktop apps, with a WinForms GUI or equivalent only. I am not interested in mobile.
In general, you can just target .NET 4.5 and compile with Visual Studio and the resulting assembly works as-is on Mono (assuming you don't use platform-specific stuff via p/invoke, etc).
Mono's WinForms support isn't perfect though (and nobody actively works on it), so you still need to test by running the app directly on Mono. Missing APIs aren't usually the problem, it's more that the Mono implementation has different behavior/bugs.
Another alternative to WinForms might be Xwt.
I was trying to follow the the installation tutorial of the Native Client SDK found here. However, my Samsung Chromebook (in developer mode) does not want to run ./naclsdk (chmod +x done), but instead returns the following:
32-bit runtime environment was not found on this
system. Specifically the 32-bit dynamic loader which is needed by the NaCl
compilers was not found ('/lib/ld-linux.so.2'). On modern debian/ubuntu
systems this is included in the 'libc6:i386' package.
On here they write that the PNaCl should run on ARM computers, however, on some other forums I read that wasn't the case. I've tried enabling two flags, as described on a site which I can't post due to a lack of reputation, but it looks like that'll only change things when using PNaCl, not during the installation of the SDK.
Is it possible to install that SDK on my Chromebook and, if so, how?
There's a bit of confusion: when the documentation says "PNaCl and NaCl work on ARM", it means the part that runs inside of Chrome which users would use. The SDK is currently only built for x86-64 Windows/Linux/OSX, and not for ARM. The main reason is that it's never been requested, probably because ARM machines are quite slow compared to usual development machines.
That being said, I don't think it's silly to use ARM as a development machine, and I've built my own PNaCl toolchain for ARM in the past. There are build instructions for the toolchain. I haven't built it recently, and it may have bitrotted a bit so if you run into issues I suggest emailing the team or better yet sending a patch! I expect any issue to be fairly minor, especially if you only want to use pnacl-clang or nacl-clang (as opposed to the GCC toolchain).
What is "node-waf" for node.js and how do I get it on a Windows development machine?
node-waf is a wrapper around the build system waf to simplify building of native C++ extensions for node.js. As far as I know there's not yet a replacement for windows.
But I know that some people managed to build native extensions with Vistual Studio instead.
This repository contains a windows build for contextify, needed for jsdom. Maybe you can look at how it is built and adapt that.
Hi I am new to android NDK Devlopment.I downloaded Android NDK 4 for windows.I read through the docs.But i am not clear with it.
First thing is that,I want to develop the native file which may be c 0r c++.I think Using Cygwin will come to play.I dont have any idea or how to use cygwin .From the Docs i just read Cygwin is required for Windows platform.Apart from it ,i dont have any knowledge about it.
Not yet started with NDK Concepts.Help Required
Cygwin is a way to make Windows support some linux functionality. If you install cygwin on your windows machine you'd be able to run some linux software on windows (you'd have to recompile it especially for cygwin though). You can find it and more information about it here. There's also a good explanation at the wiki page here.
If the Android NDK needs it I suppose the Android NDK needs some linux functionality or tools to work properly. The other option might be to install Linux on a machine and run the Android NDK on there, it might be better since I assume Linux is the native environment for Android NDK development.
Since you're saying that you're a bit unclear about the NDK, you should probably be aware that as far as I understand you can not build a whole Android app using it, you can only develop bits of it, you will still need to develop at least part of the app to run on top of the Dalvik virtual machine, which, as far as I know, means that you'll have to write that bit in Java. In general I think that you should develop Android apps only in Java unless there is a specific reason to build certain parts of it using the NDK.
From wiki:
Cygwin (pronounced /ˈsɪɡwɪn/,[2] SIG-win) is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment. Thus it is possible to launch Windows applications from the Cygwin environment, as well as to use Cygwin tools and applications within the Windows operating context.
Cygwin consists of two parts: a Dynamic-link library (DLL) as an API compatibility layer providing a substantial part of the POSIX API functionality, and an extensive collection of software tools and applications that provide a Unix-like look and feel.
So, Cygwin is a set of tools which allows you to emulate a unix-like (or linux) environment on your windows machines.
The NDK is the Android Native Development Kit. It allows you to write parts of your application in native code (C/C++) and integrate them into your application. Your application still runs under the Dalvik VM but it can load shared objects creating using a cross compiler. The NDK contains all the necessary tools and build scripts to generate native code binaries. It's an advanced concept and one you should probably wait on until you fully understand the architecture.
The reason why it requires Cygwin (or some flavor of linux) is because it uses GnuMake and other linux tools such as awk or Nawk. These tools are not available (or are really hard to use) on windows platforms, hence the need for at least Cygwin (though I would advise you do yourself a favor and just install linux).