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Appending data to existing file

Posted on 2000-05-09
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Last Modified: 2010-04-04
Appending data to existing file

var

C : String;
D : String;
F : Textfile

begin

C := #$3A+#$3B
D := #$00+#$2A

AssignFile (F, 'mama.txt');
Rewrite(F);
Writeln(F, C);
CloseFile(F);

AssignFile (F, 'mama.txt');
Append(F);
Writeln(F, D);
CloseFile(F);

end;

Every time you append to the 'mama.txt' file it tends to add a #$0D+#$0A which is exactly the same as #$0D, #$0A
From my knowledge its seems to be a [Ctrl+Z] in hex form
Does anyone know how to get rid of that extra #$0D+#$0A so that everything I append to a file is in continous line or continous string.

Ive tried this way

Assignfile (F, 'mama.txt');
Rewrite (F);
Writeln(F, C);
Writeln(F, D);

but it adds a [ASCII 26] which is not what I want

This is the extract from the Delphi Help Manual documenting the Append procedure

'If a Ctrl+Z (ASCII 26) is present in the last 128-byte block of the file, the current file position is set so that the next character added to the file overwrites the first Ctrl+Z in the block. In this way, text can be appended to a file that terminates with a Ctrl+Z.'

does anyone know how to overcome this problem?
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Comment
Question by:Ben_iti
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8 Comments
 
LVL 27

Expert Comment

by:kretzschmar
ID: 2792091
hi ben,

writeln appends alraedy$0D$0A
use write instead

#26 is allways added as file-end flag for a textfile, you can't get rid of it, if your filetyp is text.

meikl
0
 
LVL 10

Expert Comment

by:ECollin
ID: 2792093
Hi,

You can use Write instead of WriteLn.
Writeln adds the $0D,$0A at the end of the line.

Emmanuel
0
 
LVL 15

Accepted Solution

by:
simonet earned 60 total points
ID: 2792130

$D + $A  is the End-Of-Line marker. It's what makes the next character appear in the next line of the text file.

$D = CR = carriage return -> Makes the insertion point move to the beginning of the line.
$A = LF = Line feed -> Makes the insertion point move to the next line.

If you want your entire text to appear in a single line, then you can replace the WRITELN() function for WRITE() safely. Otherwise, if each entry is to appear on a different line of text, then you must keep the WRITELN() function.

Yours,

Alex
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LVL 1

Expert Comment

by:saulite
ID: 2796049
If you don't want #$0D+#$0A in every record, you must use

  write(F,C);
  write(F,D);

Instead of writeLN. It's because writeLN adds $0D+$0A, bur write - don't
0
 
LVL 27

Expert Comment

by:kretzschmar
ID: 2796463
saulite, do you think that it is fair to repaet comments as answer?

i recommend that you withdraw your answer
0
 

Author Comment

by:Ben_iti
ID: 2816500
im sorry but im going to have to unaccept your answer
thanks

Ben
0
 

Author Comment

by:Ben_iti
ID: 2824912
Congratulations Alex

The points go to you
Your answer included further documentation on the subject.

Thanks

Ben
0
 
LVL 15

Expert Comment

by:simonet
ID: 2825435
Thanks Ben. Good luck!

Alex
0

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