TCPDump-Buffer上的ReadLine有时会阻塞，直到杀死tcpdump为止
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我在Android应用程序中使用TCPDump时遇到问题。
它应该逐行读取tcpdump的输出并在我的Application中处理它。问题是：有时代码可以正常工作，它会立即读取捕获的数据包。但是有时，ReadLine会阻塞，直到我从Linux控制台（killall tcpdump）中杀死tcpdump进程为止。完成此操作后，将为每一行（有时是10，有时是1或2）处理我的循环-这意味着readLine应该可以，但没有。
我读过类似的问题，但没有找到解决该问题的任何方法……谢谢！
public class ListenActivity extends Activity {
static ArrayList<Packet> packetBuffer = new ArrayList<Packet>();
static Process tcpDumpProcess = null;
static ListenThread thread = null;
public static final String TCPDUMP_COMMAND = \"tcpdump -A -s0 | grep -i -e \'Cookie\'\\n\";
private InputStream inputStream = null;
private OutputStream outputStream = null;
@Override
protected void onStart() {
super.onStart();
try {
tcpDumpProcess = new ProcessBuilder().command(\"su\").redirectErrorStream(true).start();
inputStream = tcpDumpProcess.getInputStream();
outputStream = tcpDumpProcess.getOutputStream();
outputStream.write(TCPDUMP_COMMAND.getBytes(\"ASCII\"));
} catch (Exception e) {
Log.e(\"FSE\", \"\", e);
}
thread = new ListenThread(new BufferedReader(new InputStreamReader(inputStream)));
thread.start();
}
private class ListenThread extends Thread {
public ListenThread(BufferedReader reader) {
this.reader = reader;
}
private BufferedReader reader = null;
@Override
public void run() {
reader = new BufferedReader(new InputStreamReader(inputStream));
while (true) {
try {
String received = reader.readLine();
Log.d(\"FS\", received);
Packet pReceived = Packet.analyze(received);
if (pReceived != null) {
packetBuffer.add(pReceived);
}
} catch (Exception e) {
Log.e(\"FSE\", \"\", e);
}
}
}
}
没有找到相关结果
已邀请:
2 个回复
坝硷操
进程和进程都将等待，直到它们接收到足够的数据以免将其发送到程序中为止。不过，您很幸运，您选择使用的两个程序都准备修改其缓冲区行为（内部使用函数，以防您对细节感到好奇）： 对于：-l Make stdout line buffered. Useful if you want to see the data while capturing it. E.g., ``tcpdump -l | tee dat\'\' or ``tcpdump -l > dat & tail -f dat\'\'.：--line-buffered Use line buffering on output. This can cause a performance penalty.亲奋漏
必须更改线程内的run方法以读取输出文件：File dumpedFile = new File(\"/data/local/output.txt\"); //open a reader on the tcpdump output file BufferedReader reader = new BufferedReader(new FileReader(dumpedFile)); String temp = new String(); //The while loop is broken if the thread is interrupted while (!Thread.interrupted()) { temp = reader.readLine(); if (temp!=null) { Log.e(\"READER\",new String(temp)); } }