How to compile C into an executable binary file and run it in Android from Android Shell?

Question

I have a Device on which I installed Android Gingerbread 2.3.4 Here i want to run C executable file on android device

I am able to run android NDK application on thi

Answer 1

In a nutshell,

First, to cross-compile your C code from your host machine, use NDK toolchain with sysroot option and position independent option -fPIE -pie.

$NDKROOT/toolchains/aarch64-linux-android-4.9/prebuilt/darwin-x86_64/bin/aarch64-linux-android-gcc \
--sysroot=$NDKROOT/platforms/android-22/arch-arm64 -fPIE -pie main.c -o main

the arch part arrch64 or arch-arm64, the toolchain version part 4.9, platform version part android-22, and the binary format for your host machine darwin-x86_64 may vary by your environment.

Second, push your binary under /data/local/tmp and execute it from adb shell.

Answer 2

the "/sdcard" location is not executable, meaning that any file there is not executable at all.

the only way to "adb push" executable would be to put them in "/data/local", which should be writable for adb, and allow execution for anyone.

Answer 3

I recently had the same problem on a new nexus-5. I'd like to add that /data/local was not writable by the user ("shell", uid 2000) I got with adb shell. But putting the executable in the subdirectory /data/local/tmp/ worked fine.

Answer 4

First, let me say that my answer is dependent on your using NDK r7b (it'll work for r7c as well) on Linux (change paths appropriately for other systems).

Edit: Last tested with NDK r8e on Linux and Nexus 4 with adb from SDK Platform-Tools Rev 18 on Windows 7 (latest as of 2013-07-25) without root access.

Yet Another Edit: Please read this question for altering my instruction for native binaries that need to run on Android 5.0(Lollypop) and later.

1. Go to $NDK_ROOT (The topmost folder of NDK zip when unzipped).
2. Copy $NDK_ROOT/samples/hello-jni directory as $NDK_ROOT/sources/hello-world.
3. Go to $NDK_ROOT/sources/hello-world.
4. Edit AndroidManifest.xml to give the application an appropriate name (This is optional).
5. Go to $NDK_ROOT/sources/hello-world/jni. This is where the source code is.
6. Edit hello-jni.c, remove all the code, and put in your hello world code. Mine is:

   #include 
   int main( int argc, char* argv[])
   {
       printf("Hello, World!");
       return 0;
   }

7. Edit Android.mk and change the line include $(BUILD_SHARED_LIBRARY) to include $(BUILD_EXECUTABLE). You can also change the LOCAL_MODULE line to the name you want for your executable(default is hello-jni)
8. Go back to $NDK_ROOT/sources/hello-world
9. Run ../../ndk-build to create the executable.
10. Copy it from $NDK_ROOT/sources/hello-jni/libs/armeabi/hello-jni to /data/local/tmp on the Android device and change it's permissions to 755 (rwxr-xr-x). If you changed the LOCAL_MODULE line in $NDK_ROOT/sources/hello-world/jni/Android.mk, the executable name will be the new value of LOCAL_MODULE instead of hello-jni. (All this is done via adb from the Android SDK.)
11. Execute the binary with full path as /data/local/tmp/hello-jni, or whatever you named it to.

And you're done( and free to start on the documentation in $NDK_ROOT/docs to get a better idea of what to do).

Answer 5

The best/easiest place to put a executable is /data/local. You'll also need to chmod the binary as executable. Often you'll also need to do this in two steps to get the binary from /sdcard/ to /data/local:

$ adb push mybin /sdcard/
$ adb shell
$ cp /sdcard/mybin /data/local/mybin
$ cd /data/local
$ chmod 751 mybin

Caveats:

• Not all systems have cp. You can use cat if this is the case:

  $ cat /sdcard/mybin > /data/local/mybin

• Some systems don't allow write in /data/local for the "shell" user. Try /data/local/tmp