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

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).