保存Logcat，但只保存我需要的Android

Question

我想从LogCat保存一些数据，但我不需要所有日志，我只需要从我的自定义标签登录，如果可能从dalvikvm登录，以GC_FOR_ALLOC开头

我已经设法使用以下方法保存Logcat数据：

 Process process = Runtime.getRuntime().exec(shell);  
               //Process process =  Runtime.getRuntime().exec(new String[]{"logcat", "-d", "", "CustomTag", "*:S"});

                InputStream inputStream = process.getInputStream();  

                boolean sdCardExist = Environment.getExternalStorageState().equals(  
                        android.os.Environment.MEDIA_MOUNTED);  
                File dir = null;  
                if (sdCardExist)  
                {  
                    dir = new File(_dm.getFilePath("log.txt")); 

                    if (!dir.exists())  
                    {  
                        dir.createNewFile();  
                    }  
                }  
                byte[] buffer = new byte[1024];  
                int bytesLeft = 5 * 1024 * 1024; // Or whatever  
                try  
                {  
                    FileOutputStream fos = new FileOutputStream(dir);  
                    try  
                    {  
                        while (bytesLeft > 0)  
                        {  
                            int read = inputStream.read(buffer, 0, Math.min(bytesLeft,  
                                    buffer.length));  
                            if (read == -1)  
                            {  
                                throw new EOFException("Unexpected end of data");  
                            }  
                            fos.write(buffer, 0, read);  
                            bytesLeft -= read;  
                        }  
                    } finally  
                    {  
                        fos.close(); 
                    }  
                } finally  
                {  
                    inputStream.close();  
                }  
//                String logcat = convertStreamToString(inputStream);  
//                outputFile2SdTest(logcat, "logwyx.txt");  
                Log.v(TAG, "LOGCAT = ok" );  
            } catch (IOException e)  
            {  
                e.printStackTrace();  
            } 

但我无法保存仅从CustomTAG中保存日志。 我怎样才能做到这一点 ？ 谢谢大家