?
Solved

Read/write binary files

Posted on 1997-03-29
3
Medium Priority
?
195 Views
Last Modified: 2010-04-06
I'm trying to read the contents of a binary file into an array of records. e.g
 FileRead(FileHandle, TeamRecord[i], SizeOf(TeamRecord[i]));

The first field of the record is a string[25], and for some reason, the first letter of the string is not being read into the record. I'm new to Delphi - have I done something wrong??
0
Comment
Question by:ChrisGin
[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 3

Accepted Solution

by:
sperling earned 150 total points
ID: 1335057
This is probably because the string in the file is 0-terminated.

A pascal string stores the length of the string in the first character of the string, and then the actual data. (Not true for the D2 type STRING without any length specifier)

'ABC' pascal string :  #3 #65 #66 #67
'ABC' 0-terminated  :  #65 #66 #67 #0

What you should do, is to declare the TeamRecord type something like this:

type
  TTeamRecord =
    AString   : ARRAY [0..24] OF CHAR;
    .
    .

Or, maybe its ARRAY [0..25], depends on the binary file format.


If this didn't solve it, leave me a comment along with your record declarations and a bit more source code.

Regards,

Erik.


0
 

Author Comment

by:ChrisGin
ID: 1335058
Thanks! That solved the problem. However, by making it an array of characters, will this mean that I can no longer perform string operations on that field? If that's true, is there a conversion function I can use to convert an array of characters to a string?
0
 
LVL 3

Expert Comment

by:sperling
ID: 1335059
Yep.

StrPas(a) returns a string, if 'a' is either a PChar or a 0-terminated array of char

Regards,

Erik.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
Want to learn how to record your desktop screen without having to use an outside camera. Click on this video and learn how to use the cool google extension called "Screencastify"! Step 1: Open a new google tab Step 2: Go to the left hand upper corn…
Please read the paragraph below before following the instructions in the video — there are important caveats in the paragraph that I did not mention in the video. If your PaperPort 12 or PaperPort 14 is failing to start, or crashing, or hanging, …
Suggested Courses

649 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