I am working on a project in c#. i want to read a binary file of 64k in length which is multiple of 16 bytes. each 16 byte is an event which has the form:
#pragma noalign(trace_record)
typedef struct trace_record
{
BYTE char tr_id[2]; // 2 bytes
WORD tr_task; //2 bytes
WORD tr_process; //2 bytes
WORD tr_varies; //2 bytes
KN_TIME_STRUCT tr_time; //8 bytes
} TRACE_RECORD;
i guess using Binaryreader class i can read the file but how to read it by multiples of 16 byte in this form. later i will extract some 16 byte traces for further processing. so I will be thankful for any help. please assume i am beginner in c# :)
The simplest working example is below. It can probably be improved though. If you have big-endian data i file, you can use a MiscUtil library for example.
public struct trace_record
{
// you can create array here, but you will need to create in manually
public byte tr_id_1; // 2 bytes
public byte tr_id_2;
public UInt16 tr_task; //2 bytes
public UInt16 tr_process; //2 bytes
public UInt16 tr_varies; //2 bytes
public UInt64 tr_time; //8 bytes
}
public static List<trace_record> ReadRecords(string fileName)
{
var result = new List<trace_record>();
// store FileStream to check current position
using (FileStream s = File.OpenRead(fileName))
// and BinareReader to read values
using (BinaryReader r = new BinaryReader(s))
{
// stop when reached the file end
while (s.Position < s.Length)
{
try
{
trace_record rec = new trace_record();
// or read two bytes and use an array instead of two separate bytes.
rec.tr_id_1 = r.ReadByte();
rec.tr_id_2 = r.ReadByte();
rec.tr_task = r.ReadUInt16();
rec.tr_process = r.ReadUInt16();
rec.tr_varies = r.ReadUInt16();
rec.tr_time = r.ReadUInt64();
result.Add(rec);
}
catch
{
// handle unexpected end of file somehow.
}
}
return result;
}
}
static void Main()
{
var result = ReadRecords("d:\\in.txt");
// get all records by condition
var filtered = result.Where(r => r.tr_id_1 == 0x42);
Console.ReadKey();
}
EDIT: it's probably better to use class
instead of struct
. See Why are mutable structs “evil”? Classes are more predictable, especially if you are new to C#. And result list will then store only references to objects.
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