FileMode and TextFile not working?

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5 total messages Started by Rolf Frei Sun, 05 Nov 2006 16:35

#83

Author: Rolf Frei
Date: Sun, 05 Nov 2006 16:35

32 lines
1815 bytes

I have the following procedure to open an TextFile in readonly mode, but it 
seems not to work. It looks as the FileMode variable doesnt work with 
TextFile. I get all teh time an I/O error 32 for a textfile openend by Excel 
at the same time. Ist this correct and if so, how can I open a TextFile in 
R/O mode, to read teh file if it is open by another application?

procedure OpenReadOnlyTextFile(var F: TextFile; FileName: String);
begin
  AssignFile(F, Filename);
  FileMode := fmOpenRead;
  try
    try
      Reset(F);
    except
      on E: EInOutError do
      begin
        E.Message := RFSysErrorString(E.ErrorCode) + '. (' + FileName + ')';
        raise;
      end;
      on E: Exception do
      begin
        E.Message := E.Message + ' (' + FileName + ')';
        raise;
      end;
    end;
  finally
    FileMode := fmOpenReadWrite;
  end;
end;

Regards
Rolf

Re: FileMode and TextFile not working?

#84

Author: Kurt Barthelmess [TeamB]
Date: Mon, 06 Nov 2006 09:04

24 lines
1684 bytes

"Rolf Frei" <nospam-rolf@nospam-eicom.ch> wrote:

>I have the following procedure to open an TextFile in readonly mode, but it 
>seems not to work. It looks as the FileMode variable doesnt work with 
>TextFile. I get all teh time an I/O error 32 for a textfile openend by Excel 
>at the same time. Ist this correct and if so, how can I open a TextFile in 
>R/O mode, to read teh file if it is open by another application?

You may not be able to. If Excel has the file open with exclusive
rights, you can not get any access until it releases the file. You
might try using a FileMode of:

  fmOpenRead or fmShareDenyNone

That is the least restrictive and most accommodating access yu can
request. If that does not work, Excel will have to relases the file
first.

Note that if Excel is modifying the file, the content of what you read
is not guaranteed to be consistent.

Good luck.

Kurt

Re: FileMode and TextFile not working?

#86

Author: Peter Below TeamB
Date: Mon, 06 Nov 2006 19:19

23 lines
1665 bytes

Rolf Frei wrote:

> I have the following procedure to open an TextFile in readonly mode,
> but it seems not to work. It looks as the FileMode variable doesnt
> work with TextFile. 

Correct. The Reset routine opens a Textfile for read only access, but
it still uses a share mode that does not allow another program to open
the file.

You can open the file in the mode you want using a TFilestream. You can
then create a TStringlist and use its LoadFromStream method to load the
file contents of processing at your leisure. This way you can specify
fmReadOnly OR fmShareDenyNone as access, for example.

-- 
Peter Below (TeamB)  
Don't be a vampire (http://slash7.com/pages/vampires), 
use the newsgroup archives :
http://www.tamaracka.com/search.htm
http://groups.google.com
http://www.prolix.be

Re: FileMode and TextFile not working?

#87

Author: Jon Grewer
Date: Sun, 03 Dec 2006 14:33

27 lines
1877 bytes

I am unable to find fmReadOnly in SysUtils (D7).  Is is present in 
another unit?
The actual modes present are:
const
{ File open modes }
{$IFDEF MSWINDOWS}
  fmOpenRead       = $0000;
  fmOpenWrite      = $0001;
  fmOpenReadWrite  = $0002;

  fmShareCompat    = $0000 platform; // DOS compatibility mode is not 
portable
  fmShareExclusive = $0010;
  fmShareDenyWrite = $0020;
  fmShareDenyRead  = $0030 platform; // write-only not supported on all 
platforms
  fmShareDenyNone  = $0040;
{$ENDIF}
thanks,
--Jon G.

Peter Below (TeamB) wrote on 11/06/2006 :

> You can open the file in the mode you want using a TFilestream. You can
> then create a TStringlist and use its LoadFromStream method to load the
> file contents of processing at your leisure. This way you can specify
> fmReadOnly OR fmShareDenyNone as access, for example.

Re: FileMode and TextFile not working?

#88

Author: Wayne Niddery [TeamB]
Date: Sun, 03 Dec 2006 17:49

13 lines
1335 bytes

Jon Grewer wrote:
> I am unable to find fmReadOnly in SysUtils (D7).  Is is present in
> another unit?

>  fmOpenRead       = $0000;

Use that.


-- 
Wayne Niddery - Winwright, Inc (www.winwright.ca)
"Bandwagons are like streetcars, there'll be another along in a few
minutes."

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