AndroidT(13) -- C plus plus 语言格式的LOG输出(二)
创始人
2024-02-25 06:35:14
0次
1.概览
上一章提到的是在Android系统中，以C语言格式方式进行log输出。本章就来讲讲c++语言格式的。
std::cout<<"This is a c++ log"<在Android中也同样提供了类似的接口
LOG(INFO)<<"This is a c++ log from Android.";
不同的是不需要后加 std::endl 来告知一行结束。在Android的log系统中，天然的就认为一个LOG就对应一行内容。
2. 打印LOG内容所属的类型
2.1 输出 Android系统的LOG到logd
在 Android 中，有着非常多的子系统，所以 Android 的 LOG 系统是支持多个buffer的，即不同类型的log写入不同的buffer中。它所支持的log类型可以简单的使用对应版本的 logcat 工具查看
board:/ # logcat -h
Usage: logcat [options] [filterspecs]General options:-b, --buffer= Request alternate ring buffer(s):main system radio events crash default allAdditionally, 'kernel' for userdebug and eng builds, and'security' for Device Owner installations.Multiple -b parameters or comma separated list of buffers areallowed. Buffers are interleaved.Default -b main,system,crash,kernel. 在c++语言风格的log接口中是没办法选择buffer输出的，它们默认被输出到 main buffer中去。
2.2 打印内容所属的级别
手头需要做的事有轻重缓急，log中的信息所代表的事项也同样如此。下面是Android log 系统的几个级别
//system\libbase\include\android-base\logging.h
namespace android {
namespace base {
...
enum LogSeverity {VERBOSE,DEBUG,INFO,WARNING,ERROR,FATAL_WITHOUT_ABORT, // For loggability tests, this is considered identical to FATAL.FATAL,
...
};
}
};
前面也说了，c++风格的LOG接口只支持打印到main buffer，所以和上面的log级别组合也就如下几种
//system\libbase\include\android-base\logging.h
#define LOG(severity) LOGGING_PREAMBLE(severity) && LOG_STREAM(severity)LOG(VERBOSE)
LOG(DEBUG)
LOG(INFO)
LOG(WARNING)
LOG(ERROR)
LOG(FATAL_WITHOUT_ABORT)
LOG(FATAL)
不同级别的log使用场景可以参考上一章节。
2.3 输出 Android系统的LOG到 kmsg
上面我们所说的 main/system/radio buffer实际上都是来自于logd的内部缓存，即属于logd这个进程。
但输出log到kernel中，则需要使用到kmsg了。kmsg大家应该更加的熟悉，因为linux存在时间可比Android悠久的多，它属于linux kernel的log子系统，Android系统是基于linux，所以除了Android系统本身规划的这些log外。还有一套linux kernel的log系统，它暴露的设备节点如下
board:/ # ls /dev/kmsg -Z
u:object_r:kmsg_device:s0 /dev/kmsg
2.4 切换LOG输出 – SetLogger
Android还是一如既往的周到，提供了切换接口
//file:system\libbase\include\android-base\logging.h
LogFunction SetLogger(LogFunction&& logger);
切换kernel log
SetLogger(android::base::KernelLogger);
其中KernelLogger定义如下
// Log to the kernel log (dmesg).
void KernelLogger(LogId log_buffer_id, LogSeverity severity, const char* tag, const char* file, unsigned int line, const char* message);
在代码中，调用了如上接口后，在其之后的log都会被打印到/dev/kmsg中。我们可以通过dmesg来获取。
同样的，我们也可以将log定向到标准输出中
SetLogger(android::base::StdioLogger);
3.使用实例 – logPrintCppStyle
3.1 编译配置 – Android.bp
cc_binary {name: "logPrintCppStyle",srcs: ["*.cpp",],shared_libs: ["libbase",],cppflags: ["-Wno-unused-parameter",],
}
C语言风格的log打印接口，只使用了库 libbase，所以只要包含它即可。
3.2 测试源码 – logPrintCppStyle.cpp
#define LOG_TAG "logPrintCppStyle"#include
#include //from libbase
#include
#include
#include int main(int argc, char* argv[])
{/*1.print the log to stdio but not logdboard:/ # logcat -s logPrintCppStyle&[1] 4971board:/ # logPrintCppStyleLOG(INFO):write INFO level to main buffer*///android::base::InitLogging(nullptr, android::base::StdioLogger);/*** 2. print the log to kernel log buffer but not logd * board:/ # logPrintCppStyle* board:/ # --------- beginning of kernel* 11-25 18:22:11.924 4975 4975 I logPrintCppStyle: LOG(INFO):write INFO level to main buffer* board:/ # dmesg|grep logPrintCpp* [15331.396227] logPrintCppStyle: LOG(INFO):write INFO level to main buffer*///android::base::InitLogging(nullptr, android::base::KernelLogger);/*** 3.default:* board:/ # logPrintCppStyle* --------- beginning of main* 11-25 18:26:59.983 4980 4980 I logPrintCppStyle: LOG(INFO):write INFO level to main buffer*//*** 4.Control the log to be shown by its level* 4.1 INFO is the default level. So VERBOSE don't shows in default.* board:/ # logPrintCppStyle* 11-24 19:07:43.577 2894 2894 I logPrintCppStyle: LOG(INFO):write log* 11-24 19:07:43.578 2894 2894 W logPrintCppStyle: LOG(WARNING):write log* 11-24 19:07:43.578 2894 2894 E logPrintCppStyle: LOG(ERROR):write log* 11-24 19:07:43.578 2894 2894 F logPrintCppStyle: LOG(FATAL_WITHOUT_ABORT):write log** board:/ # setprop log.tag.logPrintCppStyle V* board:/ # logPrintCppStyle* 11-24 19:08:12.676 2925 2925 V logPrintCppStyle: LOG(VERBOSE):write log* 11-24 19:08:12.677 2925 2925 D logPrintCppStyle: LOG(DEBUG):write log* 11-24 19:08:12.677 2925 2925 I logPrintCppStyle: LOG(INFO):write log* 11-24 19:08:12.677 2925 2925 W logPrintCppStyle: LOG(WARNING):write log* 11-24 19:08:12.677 2925 2925 E logPrintCppStyle: LOG(ERROR):write log* 11-24 19:08:12.677 2925 2925 F logPrintCppStyle: LOG(FATAL_WITHOUT_ABORT):write log** board:/ # setprop log.tag.logPrintCppStyle I* board:/ # logPrintCppStyle* 11-24 19:09:17.451 2929 2929 I logPrintCppStyle: LOG(INFO):write log* 11-24 19:09:17.451 2929 2929 W logPrintCppStyle: LOG(WARNING):write log* 11-24 19:09:17.451 2929 2929 E logPrintCppStyle: LOG(ERROR):write log* 11-24 19:09:17.451 2929 2929 F logPrintCppStyle: LOG(FATAL_WITHOUT_ABORT):write log** board:/ # setprop log.tag.logPrintCppStyle E* board:/ # logPrintCppStyle* 11-24 19:09:40.640 2931 2931 E logPrintCppStyle: LOG(WARNING):write log* 11-24 19:09:40.640 2931 2931 F logPrintCppStyle: LOG(FATAL_WITHOUT_ABORT):write log** board:/ # setprop log.tag.logPrintCppStyle F* board:/ # logPrintCppStyle* 11-24 19:09:47.405 2933 2933 F logPrintCppStyle: LOG(FATAL_WITHOUT_ABORT):write log*/LOG(VERBOSE)<<"LOG(VERBOSE):write log";LOG(DEBUG)<<"LOG(DEBUG):write log";LOG(INFO)<<"LOG(INFO):write log";LOG(WARNING)<<"LOG(WARNING):write log";LOG(ERROR)<<"LOG(ERROR):write log";//LOG(FATAL_WITHOUT_ABORT)<<"LOG(FATAL_WITHOUT_ABORT):write log";//LOG(FATAL)<<"LOG(FATAL):write log";/*** 5. using PLOG to show the detial error when error occurs* 11-24 19:17:49.677 2941 2941 E logPrintCppStyle: PLOG(ERROR):write log: No such file or directory*/open("/dev/fakeDev", O_APPEND);PLOG(ERROR) << "PLOG(ERROR):write log";/*** 6.control the location where log is shown. /dev/dmesg or logd's main buffer* board:/ # logPrintCppStyle* 11-24 19:20:31.142 2943 2943 V logPrintCppStyle: LOG(VERBOSE):write log* 11-24 19:20:31.143 2943 2943 D logPrintCppStyle: LOG(DEBUG):write log* 11-24 19:20:31.143 2943 2943 I logPrintCppStyle: LOG(INFO):write log* 11-24 19:20:31.143 2943 2943 W logPrintCppStyle: LOG(WARNING):write log* 11-24 19:20:31.143 2943 2943 E logPrintCppStyle: LOG(ERROR):write log* 11-24 19:20:31.143 2943 2943 F logPrintCppStyle: LOG(FATAL_WITHOUT_ABORT):write log* 11-24 19:20:31.143 2943 2943 E logPrintCppStyle: PLOG(ERROR):write log: No such file or directory* 11-24 19:20:31.143 2943 2943 I logPrintCppStyle: set StdioLogger as Logger...* LOG(INFO):write log*/LOG(INFO)<<"set StdioLogger as Logger...";SetLogger(android::base::StdioLogger);LOG(INFO)<<"LOG(INFO):write log";SetLogger(android::base::KernelLogger);/*** 7. making the crash in the application* 11-24 19:22:38.611 2958 2958 I crash_dump64: performing dump of process 2955 (target tid = 2955)* 11-24 19:22:38.642 417 417 I logd : logdr: UID=0 GID=0 PID=2958 n tail=0 logMask=8 pid=2955 start=0ns deadline=0ns* 11-24 19:22:38.648 417 417 I logd : logdr: UID=0 GID=0 PID=2958 n tail=0 logMask=1 pid=2955 start=0ns deadline=0ns* 11-24 19:22:38.641 2958 2958 F DEBUG : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** **** 11-24 19:22:38.641 2958 2958 F DEBUG : Build fingerprint: 'Fake/full_board_t/board:13/TP1A.220624.014/eng.flagstaff.20220920.145750:userdebug/test-keys'* 11-24 19:22:38.641 2958 2958 F DEBUG : Revision: '0'* 11-24 19:22:38.641 2958 2958 F DEBUG : ABI: 'arm64'* 11-24 19:22:38.641 2958 2958 F DEBUG : Timestamp: 2022-11-24 19:22:38.613264983+0800* 11-24 19:22:38.641 2958 2958 F DEBUG : Process uptime: 2s* 11-24 19:22:38.642 2958 2958 F DEBUG : Cmdline: logPrintCppStyle* 11-24 19:22:38.642 2958 2958 F DEBUG : pid: 2955, tid: 2955, name: logPrintCppStyl >>> logPrintCppStyle <<<* 11-24 19:22:38.642 2958 2958 F DEBUG : uid: 0* 11-24 19:22:38.642 2958 2958 F DEBUG : tagged_addr_ctrl: 0000000000000001 (PR_TAGGED_ADDR_ENABLE)* 11-24 19:22:38.642 2958 2958 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault addr --------* 11-24 19:22:38.642 2958 2958 F DEBUG : Abort message: 'LOG(FATAL_WITHOUT_ABORT):write log'* 11-24 19:22:38.642 2958 2958 F DEBUG : x0 0000000000000000 x1 0000000000000b8b x2 0000000000000006 x3 0000007ffea7f850* 11-24 19:22:38.642 2958 2958 F DEBUG : x4 000000000000000a x5 000000000000000a x6 000000000000000a x7 7f7f7f7f7f7f7f7f* 11-24 19:22:38.642 2958 2958 F DEBUG : x8 00000000000000f0 x9 0000007361352a80 x10 0000000000000001 x11 0000007361393760* 11-24 19:22:38.642 2958 2958 F DEBUG : x12 0000007ffea7eb34 x13 0000000000000002 x14 0000000000000000 x15 00000073613568e2* 11-24 19:22:38.642 2958 2958 F DEBUG : x16 0000007361400d58 x17 00000073613dc2a0 x18 00000073633e4000 x19 0000000000000b8b* 11-24 19:22:38.642 2958 2958 F DEBUG : x20 0000000000000b8b x21 00000000ffffffff x22 0000007362f63000 x23 0000000000000000* 11-24 19:22:38.642 2958 2958 F DEBUG : x24 0000000000000000 x25 0000000000000000 x26 0000000000000000 x27 0000000000000000* 11-24 19:22:38.643 2958 2958 F DEBUG : x28 0000000000000000 x29 0000007ffea7f8d0* 11-24 19:22:38.643 2958 2958 F DEBUG : lr 0000007361384248 sp 0000007ffea7f830 pc 0000007361384274 pst 0000000000001000* 11-24 19:22:38.643 2958 2958 F DEBUG : backtrace:* 11-24 19:22:38.643 2958 2958 F DEBUG : #00 pc 0000000000053274 /apex/com.android.runtime/lib64/bionic/libc.so (abort+164) (BuildId: 2909e25171905ab2aa55000ddb487289)* 11-24 19:22:38.643 2958 2958 F DEBUG : #01 pc 00000000000063fc /system/lib64/liblog.so (__android_log_default_aborter+12) (BuildId: ea3eb93b960dede93d1fb67c42ed7273)* 11-24 19:22:38.643 2958 2958 F DEBUG : #02 pc 0000000000016a50 /system/lib64/libbase.so (android::base::LogMessage::~LogMessage()+352) (BuildId: 805c1dfe4ea9454d03b5d1626665b3f0)* 11-24 19:22:38.643 2958 2958 F DEBUG : #03 pc 00000000000015dc /system/bin/logPrintCppStyle (main+1404) (BuildId: f7c3609dd3aa7216053ac5cd10d3df82)* 11-24 19:22:38.643 2958 2958 F DEBUG : #04 pc 000000000004b650 /apex/com.android.runtime/lib64/bionic/libc.so (__libc_init+96) (BuildId: 2909e25171905ab2aa55000ddb487289)*///LOG(FATAL)<<"LOG(FATAL):write log";/*** 8.* 11-27 12:37:17.677 5706 5706 V logPrintCppStyle: LOG(VERBOSE):write log* 11-27 12:37:17.677 5706 5706 D logPrintCppStyle: LOG(DEBUG):write log* 11-27 12:37:17.677 5706 5706 I logPrintCppStyle: LOG(INFO):write log* 11-27 12:37:17.678 5706 5706 W logPrintCppStyle: LOG(WARNING):write log* 11-27 12:37:17.678 5706 5706 E logPrintCppStyle: LOG(ERROR):write log* 11-27 12:37:17.678 5706 5706 E logPrintCppStyle: PLOG(ERROR):write log: No such file or directory* 11-27 12:37:17.678 5706 5706 I logPrintCppStyle: set StdioLogger as Logger...* 11-27 12:37:17.687 5706 5706 F logPrintCppStyle: Check failed: false == true (false=0, true=1)* error information:* 11-27 12:37:17.724 5709 5709 F DEBUG : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** **** 11-27 12:37:17.724 5709 5709 F DEBUG : Build fingerprint: 'Fake/full_board_t/board:13/TP1A.220624.014/eng.flagstaff.20220920.145750:userdebug/test-keys'* 11-27 12:37:17.724 5709 5709 F DEBUG : Revision: '0'* 11-27 12:37:17.724 5709 5709 F DEBUG : ABI: 'arm64'* 11-27 12:37:17.724 5709 5709 F DEBUG : Timestamp: 2022-11-27 12:37:17.707826659+0800* 11-27 12:37:17.724 5709 5709 F DEBUG : Process uptime: 1s* 11-27 12:37:17.724 5709 5709 F DEBUG : Cmdline: logPrintCppStyle* 11-27 12:37:17.724 5709 5709 F DEBUG : pid: 5706, tid: 5706, name: logPrintCppStyl >>> logPrintCppStyle <<<* 11-27 12:37:17.724 5709 5709 F DEBUG : uid: 0* 11-27 12:37:17.724 5709 5709 F DEBUG : tagged_addr_ctrl: 0000000000000001 (PR_TAGGED_ADDR_ENABLE)* 11-27 12:37:17.725 5709 5709 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault addr --------* 11-27 12:37:17.725 5709 5709 F DEBUG : Abort message: 'Check failed: false == true (false=0, true=1) '* 11-27 12:37:17.725 5709 5709 F DEBUG : x0 0000000000000000 x1 000000000000164a x2 0000000000000006 x3 0000007fde3c3c90* 11-27 12:37:17.725 5709 5709 F DEBUG : x4 000000000000000a x5 000000000000000a x6 000000000000000a x7 7f7f7f7f7f7f7f7f* 11-27 12:37:17.725 5709 5709 F DEBUG : x8 00000000000000f0 x9 0000007864688a80 x10 0000000000000001 x11 00000078646c9760* 11-27 12:37:17.725 5709 5709 F DEBUG : x12 0000007fde3c2f74 x13 0000000000000002 x14 0000000000000000 x15 000000786468c8e2* 11-27 12:37:17.725 5709 5709 F DEBUG : x16 0000007864736d58 x17 00000078647122a0 x18 0000007868288000 x19 000000000000164a* 11-27 12:37:17.725 5709 5709 F DEBUG : x20 000000000000164a x21 00000000ffffffff x22 0000007867a27000 x23 00000058c8e3fb8e* 11-27 12:37:17.725 5709 5709 F DEBUG : x24 00000058c8e3fc17 x25 00000058c8e3fc1a x26 00000058c8e3fc6c x27 00000058c8e3fbb3* 11-27 12:37:17.725 5709 5709 F DEBUG : x28 00000058c8e3fc8c x29 0000007fde3c3d10* 11-27 12:37:17.725 5709 5709 F DEBUG : lr 00000078646ba248 sp 0000007fde3c3c70 pc 00000078646ba274 pst 0000000000001000* 11-27 12:37:17.725 5709 5709 F DEBUG : backtrace:* 11-27 12:37:17.725 5709 5709 F DEBUG : #00 pc 0000000000053274 /apex/com.android.runtime/lib64/bionic/libc.so (abort+164) (BuildId: 2909e25171905ab2aa55000ddb487289)* 11-27 12:37:17.725 5709 5709 F DEBUG : #01 pc 00000000000063fc /system/lib64/liblog.so (__android_log_default_aborter+12) (BuildId: ea3eb93b960dede93d1fb67c42ed7273)* 11-27 12:37:17.725 5709 5709 F DEBUG : #02 pc 0000000000016a50 /system/lib64/libbase.so (android::base::LogMessage::~LogMessage()+352) (BuildId: 805c1dfe4ea9454d03b5d1626665b3f0)* 11-27 12:37:17.725 5709 5709 F DEBUG : #03 pc 000000000000131c /system/bin/logPrintCppStyle (main+700) (BuildId: dc17c42573ba586fece229f605ff661a)* 11-27 12:37:17.726 5709 5709 F DEBUG : #04 pc 000000000004b650 /apex/com.android.runtime/lib64/bionic/libc.so (__libc_init+96) (BuildId: 2909e25171905ab2aa55000ddb487289)*/CHECK_EQ(false, true);return EXIT_SUCCESS;
}
上面的例子大致包含了如下几种用法
a)使用接口SetLogger设置log的输出位置，其中 InitLogging 的功能和它是类似的，只不过更加自由，可以重新设置abort级别的log输出。
b)输出各级别的log
c)PLOG的使用，这个还是比较有意思的，因为他会直接把错误码直接转换成人类可阅读的形式输出log，下面是例子
/*** 5. using PLOG to show the detial error when error occurs* 11-24 19:17:49.677 2941 2941 E logPrintCppStyle: PLOG(ERROR):write log: No such file or directory*/open("/dev/fakeDev", O_APPEND);PLOG(ERROR) << "PLOG(ERROR):write log";
d)FATAL级别和CHECK_XX系列的接口，前者会直接造成程序进入abort分支，导致程序异常退出。后者在条件满足的条件下和前者表现完全一致
/*** 8.* 11-27 12:37:17.677 5706 5706 V logPrintCppStyle: LOG(VERBOSE):write log* 11-27 12:37:17.677 5706 5706 D logPrintCppStyle: LOG(DEBUG):write log* 11-27 12:37:17.677 5706 5706 I logPrintCppStyle: LOG(INFO):write log* 11-27 12:37:17.678 5706 5706 W logPrintCppStyle: LOG(WARNING):write log* 11-27 12:37:17.678 5706 5706 E logPrintCppStyle: LOG(ERROR):write log* 11-27 12:37:17.678 5706 5706 E logPrintCppStyle: PLOG(ERROR):write log: No such file or directory* 11-27 12:37:17.678 5706 5706 I logPrintCppStyle: set StdioLogger as Logger...* 11-27 12:37:17.687 5706 5706 F logPrintCppStyle: Check failed: false == true (false=0, true=1)* error information:* 11-27 12:37:17.724 5709 5709 F DEBUG : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** **** 11-27 12:37:17.724 5709 5709 F DEBUG : Build fingerprint: 'Fake/full_board_t/board:13/TP1A.220624.014/eng.flagstaff.20220920.145750:userdebug/test-keys'* 11-27 12:37:17.724 5709 5709 F DEBUG : Revision: '0'* 11-27 12:37:17.724 5709 5709 F DEBUG : ABI: 'arm64'* 11-27 12:37:17.724 5709 5709 F DEBUG : Timestamp: 2022-11-27 12:37:17.707826659+0800* 11-27 12:37:17.724 5709 5709 F DEBUG : Process uptime: 1s* 11-27 12:37:17.724 5709 5709 F DEBUG : Cmdline: logPrintCppStyle* 11-27 12:37:17.724 5709 5709 F DEBUG : pid: 5706, tid: 5706, name: logPrintCppStyl >>> logPrintCppStyle <<<* 11-27 12:37:17.724 5709 5709 F DEBUG : uid: 0* 11-27 12:37:17.724 5709 5709 F DEBUG : tagged_addr_ctrl: 0000000000000001 (PR_TAGGED_ADDR_ENABLE)* 11-27 12:37:17.725 5709 5709 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault addr --------* 11-27 12:37:17.725 5709 5709 F DEBUG : Abort message: 'Check failed: false == true (false=0, true=1) '* 11-27 12:37:17.725 5709 5709 F DEBUG : x0 0000000000000000 x1 000000000000164a x2 0000000000000006 x3 0000007fde3c3c90* 11-27 12:37:17.725 5709 5709 F DEBUG : x4 000000000000000a x5 000000000000000a x6 000000000000000a x7 7f7f7f7f7f7f7f7f* 11-27 12:37:17.725 5709 5709 F DEBUG : x8 00000000000000f0 x9 0000007864688a80 x10 0000000000000001 x11 00000078646c9760* 11-27 12:37:17.725 5709 5709 F DEBUG : x12 0000007fde3c2f74 x13 0000000000000002 x14 0000000000000000 x15 000000786468c8e2* 11-27 12:37:17.725 5709 5709 F DEBUG : x16 0000007864736d58 x17 00000078647122a0 x18 0000007868288000 x19 000000000000164a* 11-27 12:37:17.725 5709 5709 F DEBUG : x20 000000000000164a x21 00000000ffffffff x22 0000007867a27000 x23 00000058c8e3fb8e* 11-27 12:37:17.725 5709 5709 F DEBUG : x24 00000058c8e3fc17 x25 00000058c8e3fc1a x26 00000058c8e3fc6c x27 00000058c8e3fbb3* 11-27 12:37:17.725 5709 5709 F DEBUG : x28 00000058c8e3fc8c x29 0000007fde3c3d10* 11-27 12:37:17.725 5709 5709 F DEBUG : lr 00000078646ba248 sp 0000007fde3c3c70 pc 00000078646ba274 pst 0000000000001000* 11-27 12:37:17.725 5709 5709 F DEBUG : backtrace:* 11-27 12:37:17.725 5709 5709 F DEBUG : #00 pc 0000000000053274 /apex/com.android.runtime/lib64/bionic/libc.so (abort+164) (BuildId: 2909e25171905ab2aa55000ddb487289)* 11-27 12:37:17.725 5709 5709 F DEBUG : #01 pc 00000000000063fc /system/lib64/liblog.so (__android_log_default_aborter+12) (BuildId: ea3eb93b960dede93d1fb67c42ed7273)* 11-27 12:37:17.725 5709 5709 F DEBUG : #02 pc 0000000000016a50 /system/lib64/libbase.so (android::base::LogMessage::~LogMessage()+352) (BuildId: 805c1dfe4ea9454d03b5d1626665b3f0)* 11-27 12:37:17.725 5709 5709 F DEBUG : #03 pc 000000000000131c /system/bin/logPrintCppStyle (main+700) (BuildId: dc17c42573ba586fece229f605ff661a)* 11-27 12:37:17.726 5709 5709 F DEBUG : #04 pc 000000000004b650 /apex/com.android.runtime/lib64/bionic/libc.so (__libc_init+96) (BuildId: 2909e25171905ab2aa55000ddb487289)*/CHECK_EQ(false, true);
4.使用属性控制log级别输出
打印到logd中的log和C语言形式的log一样，也是支持根据log级别做有选择的方式进行输出的。但对于输出到标准输出以及kmsg的情况则是不适用的。
board:/ # setprop log.tag.logPrintCppStyle V
board:/ # logPrintCppStyle
LOG(INFO):write log
11-27 17:20:19.197 5914 5914 V logPrintCppStyle: LOG(VERBOSE):write log
11-27 17:20:19.197 5914 5914 D logPrintCppStyle: LOG(DEBUG):write log
11-27 17:20:19.197 5914 5914 I logPrintCppStyle: LOG(INFO):write log
11-27 17:20:19.197 5914 5914 W logPrintCppStyle: LOG(WARNING):write log
11-27 17:20:19.197 5914 5914 E logPrintCppStyle: LOG(ERROR):write log
11-27 17:20:19.197 5914 5914 E logPrintCppStyle: PLOG(ERROR):write log: No such file or directory
11-27 17:20:19.197 5914 5914 I logPrintCppStyle: set StdioLogger as Logger...
11-27 17:20:19.206 5914 5914 F logPrintCppStyle: Check failed: false == true (false=0, true=1)
Aborted
board:/ # setprop log.tag.logPrintCppStyle E
board:/ # logPrintCppStyle
11-27 17:20:24.767 5923 5923 E logPrintCppStyle: LOG(ERROR):write log
11-27 17:20:24.767 5923 5923 E logPrintCppStyle: PLOG(ERROR):write log: No such file or directory
11-27 17:20:24.775 5923 5923 F logPrintCppStyle: Check failed: false == true (false=0, true=1)
Aborted
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美国总统特朗普15日在卡塔尔出席一场商业圆桌会议时再次宣称，美国可以“接管加沙”，并将其打造为一个“...
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交通银行与工业和信息化部火炬中...
转自：北京商报5月16日，交通银行与工业和信息化部火炬中心联合发起的走进千企万户“五个一”专项行动之...
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又见“长存利少”！多家银行存款...
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600671、002092、6...
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巴西首次报告商业养殖场高致病性...
巴西农业部16日发布公报，确认该国南部一处商业养殖场出现家禽感染高致病性禽流感病毒病例。这是该国首次...
一女子被医院强制带走治疗！官方...
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中新网太原5月17日电 (记者 胡健)日前，晋祠博物馆联合太原市双塔西街小学共同开展“流动博物馆进校...
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联合国呼吁以色列与胡塞武装立即...
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