Android中dumpsys函数介绍与使用

dumpsys是系统中重要的函数，我们来看看它如何使用，都能dump出来一些什么东西

首先我们来看看dumpsys的源码，在4.1中，它在framework/native目录下面

frameworks/native/cmds/dumpsys/dumpsys.cpp

if (argc == 1) {
services = sm->listServices();
services.sort(sort_func);
args.add(String16("-a"));
} else {
services.add(String16(argv[1]));
for (int i=2; i args.add(String16(argv[i]));
}
}

const size_t N = services.size();

if (N > 1) {
// first print a list of the current services
aout << "Currently running services:" << endl;

for (size_t i=0; i sp service = sm->checkService(services[i]);
if (service != NULL) {
aout << " " << services[i] << endl;
}
}
}

for (size_t i=0; i sp service = sm->checkService(services[i]);
if (service != NULL) {
if (N > 1) {//dump多个Service时，Service信息之间的分隔
aout << "------------------------------------------------------------"
"-------------------" << endl;
aout << "DUMP OF SERVICE " << services[i] << ":" << endl;
}
int err = service->dump(STDOUT_FILENO, args);
if (err != 0) {
aerr << "Error dumping service info: (" << strerror(err)
<< ") " << services[i] << endl;
}
} else {
aerr << "Can't find service: " << services[i] << endl;
}
}

我只会java，上面的代码还是留给大家自己阅读吧，我就不详细解释了……

如果参数个数=1，则在ServiceManager中查找注册的Service

否则查找指定的Service，并且将剩余参数传给Serivce

如果执行dumpsys命令，那么将会dump所有Service，每个Service之间会分隔开

如果dumpsys一个没有注册的Service，那么则提示找不到Service，比如：

# dumpsys adb

Can't find service: adb