I just try to do a ndk-build for a simple hello program.

Android.mk file:

```
LOCAL_PATH:= $(call my-dir) # Get the local path of the project.
include $(CLEAR_VARS) # Clear all the variables with a prefix "LOCAL_"

LOCAL_SRC_FILES:=hello.cpp # Indicate the source code.
LOCAL_MODULE:= hello # The name of the binary.
LOCAL_ARM_MODE := arm
include $(BUILD_EXECUTABLE) # Tell ndk-build that we want to build a native executable.

```

Application.mk file:

```
APP_ABI := armeabi-v7a # Define the target architecture to be ARM.
APP_STL := gnustl_static
#APP_STL := gnustl_static
APP_CPPFLAGS := -frtti -fexceptions    # This is the place you enable exception.
APP_PLATFORM = android-19

```

source file (hello.cpp):

```
#include <iostream>

int main(int argc, char* argv[])
{
    std::cout<<"Hello from world!"<<std::endl;
    for(int i=0; i<argc; ++i)
        std::cout<<"Arg "<<i<<" is: "<<argv[i]<<std::endl;
    return 0;
}

```

The ndk-build is success:

```
[armeabi-v7a] Compile++ arm  : hello <= hello.cpp
[armeabi-v7a] Executable     : hello
[armeabi-v7a] Install        : hello => libs/armeabi-v7a/hello

```

But after I pushed this to the emulator and try to execute, I got this error:
**/system/bin/sh: ./hello: not executable: 32-bit ELF file**

Check with file command and it shows as:
**file libs/armeabi-v7a/hello
libs/armeabi-v7a/hello: ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /system/bin/linker, stripped**

Chck with readelf:
readelf --file-header libs/armeabi-v7a/hello

```
ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              DYN (Shared object file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x3898
  Start of program headers:          52 (bytes into file)
  Start of section headers:          205324 (bytes into file)
  Flags:                             0x5000200, Version5 EABI, soft-float ABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         8
  Size of section headers:           40 (bytes)
  Number of section headers:         26
  Section header string table index: 25

```

So, what's wrong with my setting? Just can't figure out why. 
Thanks in advance.