StreamReader is not reading my entire file?

Question

Resolved:

The file on the SD card has a bunch of NULLs at that point in the file.

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I am using the Netduino Plus to read text from a file on the SD card. I'm using C# .NET Micro Framework 4.2 and FileReader / StreamReader to get it done. I've read the StreamReader buffer is 512 bytes long. Can you only read 512 bytes of data with the StreamReader and that's it? Here's why I'm wondering and a description of my problem...

Here's an example of the file that I'm reading...

40
3,241,17,17,1000,2000
3,14,92,223,1000,2000
3,101,229,12,1000,2000
3,16,215,228,1000,2000
3,50,240,11,1000,2000
3,232,213,10,1000,2000
3,234,219,219,1000,2000
3,202,13,222,1000,2000
3,240,5,65,1000,2000
3,25,234,3,1000,2000
3,236,5,164,1000,2000
3,26,229,12,1000,2000
3,225,217,18,1000,2000
3,8,229,216,1000,2000
3,49,0,7,1000,2000
3,12,99,190,1000,2000
3,222,7,226,1000,2000
3,12,221,208,1000,2000
3,4,37,227,1000,2000
3,4,122,48,1000,2000
3,88,181,192,1000,2000
3,1,17,222,1000,2000
3,56,235,19,1000,2000
3,236,15,101,1000,2000
3,13,175,231,1000,2000
3,229,218,17,1000,2000
3,9,74,239,1000,2000
3,10,233,17,1000,2000
3,12,73,227,1000,2000
3,234,3,3,1000,2000
3,7,128,110,1000,2000
3,5,209,241,1000,2000
3,8,61,229,1000,2000
3,237,1,238,1000,2000
3,228,19,19,1000,2000
3,16,228,92,1000,2000
3,243,206,14,1000,2000
3,193,3,220,1000,2000
3,236,7,7,1000,2000
3,115,236,7,1000,2000

-The first line indicates how many lines are to follow. -The first number in the following lines indicates how many data items will be read from the line. (in this example there are 3 data elements on each line) -The last two numbers on the line are times in ms.

My code reads this much of the file and stops.

40
3,241,17,17,1000,2000
3,14,92,223,1000,2000
3,101,229,12,1000,2000
3,16,215,228,1000,2000
3,50,240,11,1000,2000
3,232,213,10,1000,2000
3,234,219,219,1000,2000
3,202,13,222,1000,2000
3,240,5,65,1000,2000
3,25,234,3,1000,2000
3,236,5,164,1000,2000
3,26,229,12,1000,2000
3,225,217,18,1000,2000
3,8,229,216,1000,2000
3,49,0,7,1000,2000
3,12,99,190,1000,2000
3,222,7,226,1000,2000
3,12,221,208,1000,2000
3,4,37,227,1000,2000
3,4,122,48,1000,2000
3,88,181,192,1000,2000
3,1,17,222,1000,2000
3,56,235,19,1000,2000
3,236,15,101,1000,2000
3,13,175,231,1000,2000
3,229,218,17,1000,2000
3,9,74,239,1000,2000
3,10,233,17


other lines are not read

It misses the two time values on this readline call and the code breaks out on the assignment of time2 in the code below on a System.IndexOutOfRangeException since linearry is 5 elements long (the null doesn't nicely convert to an int lol) and looks like....

linearray[0] = "3"
linearray[1] = "10"
linearray[2] = "233"
linearray[3] = "17"
linearray[4] = ""

instead of being 6 elements long like the rest of the lines and looking like....

linearray[0] = "3"
linearray[1] = "10"
linearray[2] = "233"
linearray[3] = "17"
linearray[4] = "1000"
linearray[5] = "2000"

All the previous lines are read fine and linearray contains all the data it should. Am I not using StreamReader correctly?

Here's the code....

            FileStream fs2 = new FileStream(FilePath, FileMode.Open, FileAccess.Read, FileShare.None);
            StreamReader sr = new StreamReader(fs2);

            line = sr.ReadLine();

            numLines = Convert.ToInt32(line);

            line = "";
            for (int i = 0; i < numLines; i++)
            {
                line = sr.ReadLine();
                string[] linearray = line.Split(comma);
                numDataElements[i] = int.Parse(linearray[0]);

                for (int j = 1; j <= numDataElements[i]; j++)
                {
                    readData[i][j] = byte.Parse(linearray[j]);
                }
                //clear the rest of the channels
                for (int j = (numDataElements[i]+1); j <= MAXCHANNELS; j++)
                {
                    data[i][j] = (byte)0;
                }

                time1[i] = Convert.ToInt32(linearray[linearray.Length - 2]);
                time2[i] = Convert.ToInt32(linearray[linearray.Length - 1]);

            }

Thanks!

Answer 1

Just to answer this question, there was nothing wrong with the code above. I found a bug in the FTP server library . It was also using a 512 byte buffer and only writing that buffer is is was FULL. So that second buffer that was partially full was never written out to the incoming file. I fixed the FTP library code and all is good!