Question

我在构建使用本机（JNI）库的Android应用程序（GUI）方面取得了成功。

但是，现在我想创建一个从命令行运行的可执行文件（root权限），并且根本不使用GUI。我如何建立这样的东西？

Answer 1

从NDK r8d开始，这可以通过更简单的方式解决。

使用以下目录层次结构创建项目：

project/
    jni/
        Android.mk
        Application.mk
        *.c, *.cpp, *.h, etc.

使用以下内容填写Android.mk。最重要的是最后一行。检查NDK doc以了解其他变量的含义。

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE := name-of-your-executable
LOCAL_SRC_FILES := a.cpp b.cpp c.cpp etc.cpp
LOCAL_CPPFLAGS := -std=gnu++0x -Wall -fPIE         # whatever g++ flags you like
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog -fPIE -pie   # whatever ld flags you like

include $(BUILD_EXECUTABLE)    # <-- Use this to build an executable.

转到project/目录，然后输入
```
ndk-build
```
结果将放在project/libs/<arch>/name-of-your-executable。

Answer 2

http://www.bekatul.info/content/native-c-application-android [已破碎（2015年11月9日）]

总结文章......

测试代码为：

#include  <stdio.h>//for printf
#include  <stdlib.h>//for exit

int main(int argc, char **argv)
{
        int i = 1;
        i+=2;

        printf("Hello, world (i=%d)!\n", i);

        return 0;
        exit(0);
}

Makefile是：

APP := test
ROOT := /home/dd/android
INSTALL_DIR := /data/tmp
NDK_PLATFORM_VER := 8

ANDROID_NDK_ROOT := $(ROOT)/android-ndk-r5
ANDROID_NDK_HOST := linux-x86
ANDROID_SDK_ROOT := $(ROOT)/android-sdk-linux_86
PREBUILD := $(ANDROID_NDK_ROOT)/toolchains/arm-eabi-4.4.0/prebuilt/$(ANDROID_NDK_HOST)

BIN := $(PREBUILD)/bin/
LIB := $(ANDROID_NDK_ROOT)/platforms/android-$(NDK_PLATFORM_VER)/arch-arm/usr/lib
INCLUDE := $(ANDROID_NDK_ROOT)/platforms/android-$(NDK_PLATFORM_VER)/arch-arm/usr/include

CC := $(BIN)/arm-eabi-gcc
GDB_CLIENT := $(BIN)/arm-eabi-gdb

LIBCRT := $(LIB)/crtbegin_dynamic.o

LINKER := /system/bin/linker

DEBUG := -g

CFLAGS := $(DEBUG) -fno-short-enums -I$(INCLUDE)
CFLAGS += -Wl,-rpath-link=$(LIB),-dynamic-linker=$(LINKER) -L$(LIB)
CFLAGS += -nostdlib -lc

all: $(APP)

$(APP): $(APP).c
        $(CC) -o $@ $< $(CFLAGS) $(LIBCRT)

install: $(APP)
        $(ANDROID_SDK_ROOT)/platform-tools/adb push $(APP) $(INSTALL_DIR)/$(APP) 
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell chmod 777 $(INSTALL_DIR)/$(APP)

shell:
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell

run:
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell $(INSTALL_DIR)/$(APP)

debug-install:
        $(ANDROID_SDK_ROOT)/platform-tools/adb push $(PREBUILD)/../gdbserver $(INSTALL_DIR)/gdbserver
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell chmod 777 $(INSTALL_DIR)/gdbserver

debug-go:
        $(ANDROID_SDK_ROOT)/platform-tools/adb forward tcp:1234: tcp:1234
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell $(INSTALL_DIR)/gdbserver :1234 $(INSTALL_DIR)/$(APP)

debug:
        $(GDB_CLIENT) $(APP)

clean:
        @rm -f $(APP).o $(APP)

作者将这些文件存储在他/她的本地Linux计算机上：

/home/dd/android/dev/native/test.c
/home/dd/android/dev/native/Makefile

然后，作者编写并测试了它：

dd@abil:~/android/dev/native$ make clean; make; make install; make run
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-gcc -c  -fno-short-enums -I/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/include test.c -o test.o 
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-g++ -Wl,--entry=main,-dynamic-linker=/system/bin/linker,-rpath-link=/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -L/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -nostdlib -lc -o test test.o
/home/dd/android/android-sdk-linux_86/platform-tools/adb push test /data/tmp/test 
45 KB/s (2545 bytes in 0.054s)
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell chmod 777 /data/tmp/test
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell /data/tmp/test
Hello, world (i=3)!

使用的SDK和NDK是：

source code: /home/dd/android/dev/native
android ndk: /home/dd/android/android-ndk-r5
android sdk: /home/dd/android/android-sdk-linux_86

然而，调试指南是非常好的部分！复制并粘贴......

设置编译以启用调试：

DEBUG = -g
CFLAGS := $(DEBUG) -fno-short-enums -I$(ANDROID_NDK_ROOT)/platforms/android-$(NDK_PLATFORM_VER)/arch-arm/usr/include

将gdbserver文件（$（PREBUILD）/../ gdbserver）复制到模拟器，在Makefile中添加目标，而不是简化：

debug-install:
        $(ANDROID_SDK_ROOT)/platform-tools/adb push $(PREBUILD)/../gdbserver $(INSTALL_DIR)/gdbserver
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell chmod 777 $(INSTALL_DIR)/gdbserver

现在我们将调试它@port 1234：

debug-go:
        $(ANDROID_SDK_ROOT)/platform-tools/adb forward tcp:1234: tcp:1234
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell $(INSTALL_DIR)/gdbserver :1234 $(INSTALL_DIR)/$(APP)

然后执行它：

dd@abil:~/android/dev/native$ make clean; make; make install; make debug-install; make debug-go
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-gcc -c  -g -fno-short-enums -I/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/include test.c -o test.o 
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-g++ -Wl,--entry=main,-dynamic-linker=/system/bin/linker,-rpath-link=/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -L/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -nostdlib -lc -o test test.o
/home/dd/android/android-sdk-linux_86/platform-tools/adb push test /data/tmp/test 
71 KB/s (3761 bytes in 0.051s)
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell chmod 777 /data/tmp/test
/home/dd/android/android-sdk-linux_86/platform-tools/adb push /home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/../gdbserver /data/tmp/gdbserver
895 KB/s (118600 bytes in 0.129s)
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell chmod 777 /data/tmp/gdbserver
/home/dd/android/android-sdk-linux_86/platform-tools/adb forward tcp:1234: tcp:1234
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell /data/tmp/gdbserver :1234 /data/tmp/test
Process /data/tmp/test created; pid = 472
Listening on port 1234

现在打开其他控制台并执行调试器：

dd@abil:~/android/dev/native$ make debug
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-gdb test
GNU gdb 6.6
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "--host=x86_64-linux-gnu --target=arm-elf-linux"...
(gdb) target remote :1234
Remote debugging using :1234
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers
and track explicitly loaded dynamic code.
0xb0001000 in ?? ()
(gdb) b main
Breakpoint 1 at 0x82fc: file test.c, line 6.
(gdb) c
Continuing.
Error while mapping shared library sections:
/system/bin/linker: No such file or directory.
Error while mapping shared library sections:
libc.so: Success.

Breakpoint 1, main (argc=33512, argv=0x0) at test.c:6
6               int i = 1;
(gdb) n
7               i+=2;
(gdb) p i
$1 = 1
(gdb) n
9               printf("Hello, world (i=%d)!\n", i);
(gdb) p i
$2 = 3
(gdb) c
Continuing.

Program exited normally.
(gdb) quit

好吧，没关系。而另一个控制台将提供额外的输出：

Remote debugging from host 127.0.0.1
gdb: Unable to get location for thread creation breakpoint: requested event is not supported
Hello, world (i=3)!

Child exited with retcode = 0 

Child exited with status 0
GDBserver exiting

Answer 3

这是一个遵循KennyTM答案的示例项目。您可以从头开始创建它或修改另一个项目，例如，NDK样本中的hello-jni。

JNI / main.c中：

#include <stdio.h>
int main() {
    printf("hello\n");
    return 0;
}

JNI / Application.mk：

#APP_ABI := all
APP_ABI := armeabi-v7a

JNI / Android.mk：

LOCAL_PATH := $(call my-dir)

# first target: the hello-jni example
# it shows how to build multiple targets
# {{ you may comment it out
include $(CLEAR_VARS)

LOCAL_MODULE    := hello-jni
LOCAL_SRC_FILES := hello-jni.c
LOCAL_LDLIBS := -llog -L$(LOCAL_PATH)/lib -lmystuff # link to libmystuff.so

include $(BUILD_SHARED_LIBRARY)
#}} you may comment it out


# second target
include $(CLEAR_VARS)

LOCAL_MODULE := hello
LOCAL_SRC_FILES := main.c

include $(BUILD_EXECUTABLE)    # <-- Use this to build an executable.

我必须注意，您不会在stdout输出中看到任何记录，您必须使用adb logcat才能看到它。

所以如果你想要记录：

JNI / main.c中：

#include <stdio.h>
#include <android/log.h>
int main() {
    printf("hello\n");
    __android_log_print(ANDROID_LOG_DEBUG  , "~~~~~~", "log %i", 0); // the 3rd arg is a printf-style format string
    return 0;
}

并且 jni / Android.mk 中的相应部分变为：

LOCAL_PATH := $(call my-dir)

#...

include $(CLEAR_VARS)

LOCAL_MODULE := hello
LOCAL_SRC_FILES := main.c
LOCAL_LDLIBS := -llog   # no need to specify path for liblog.so

include $(BUILD_EXECUTABLE)    # <-- Use this to build an executable.

Answer 4

Someone Somewhere's answer让我朝着正确的方向前进，但它包含错误/误判。

就gdbserver而言，adb命令

$(ANDROID_SDK_ROOT)/platform-tools/adb push $(PREBUILD)/../gdbserver $(INSTALL_DIR)/gdbserver

由于显而易见的原因，

永远无法工作，因为“目录”$（PREBUILD）和gdbserver之间存在目录android-arm。最好设置

PREBUILDDEBUG=$(ANDROID_NDK_ROOT)/prebuilt/android-arm

并用

替换以前的命令

$(ANDROID_SDK_ROOT)/platform-tools/adb push $(PREBUILDDEBUG)/gdbserver $(INSTALL_DIR)/gdbserver

这一切都适用于我的Android虚拟设备。（没有明显的分段错误。）在我的真实设备上，我确实有分段错误。

make run

一部分。关于调试部分，无论是在模拟器上还是在真实设备上，当我这样做时，我总是得到“无法访问内存”

b main

在gdb模式下。我不知道为什么。

如何构建在Android上运行的本机（命令行）可执行文件？

4 个答案: