Solved

Reading and writing Binary Data

Posted on 1998-05-07
3
136 Views
Last Modified: 2010-04-06
I have a file with a 128 byte header field, followed by RFC-822 text.  How would I go about reading in the binary header data from this file so that the data can be manipulated and/or added to the top of another existing text file.
0
Comment
Question by:sparklin
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 5

Accepted Solution

by:
inter earned 100 total points
ID: 1342562
Hi,
I propese the following code fragments:

READING BINARY DATA(128byte)
-------------------------------------
This code returns the first 128 bytes of a file named F in variable H:

type
 THeader = array[0..127] of byte;

function ReadHeader(F : string; var H : THeader):boolean;
var
  F : TFileStream;
begin
  F := TFileStream.Create(F, fmOpenRead);
  try
    F.Read(H, SizeOf(THeader));
    Result := true;
  finally
    F.Free;
  end;
end;

GIVEN HEADER READED BY ABOVE APPEND IT TO ANOTHER TEXT FILE

This routine adds the given header to the top of existing text file named F
and create a new file named N.

function AttachHeader(F,N : string; const H : THeader):boolean;
var
  T : TStringList;
  M : TMemoryStream;
begin
  F := TFileStream.Create(N, fmCreate or fmOpenWrite);
  M := TMemoryStream.Create;
  try
    //read text file
    M.LoadFromFile(F);
    //Write header to new file
    F.Write(H, SizeOf(THeader));
    //Append text file to the end of new file
    M.SaveToStream(F);
    Result := true;
  finally
    M.Free;
    F.Free;
  end;
end;


Regards,
Igor
0
 
LVL 4

Expert Comment

by:d003303
ID: 1342563
Hi d003303, (and sparklin ofcourse)
Did I understand the question wrong. If so, excuse me to post it as answer.
Regards,
Igor
0
 
LVL 5

Expert Comment

by:inter
ID: 1342564
Thanks guys.  I think that pretty much covers what I needed to confirm.
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Introduction The parallel port is a very commonly known port, it was widely used to connect a printer to the PC, if you look at the back of your computer, for those who don't have newer computers, there will be a port with 25 pins and a small print…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
Finding and deleting duplicate (picture) files can be a time consuming task. My wife and I, our three kids and their families all share one dilemma: Managing our pictures. Between desktops, laptops, phones, tablets, and cameras; over the last decade…
This video shows how to use Hyena, from SystemTools Software, to update 100 user accounts from an external text file. View in 1080p for best video quality.

751 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question