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I/O error 104 when printing a file

mathes
mathes asked
on
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Last Modified: 2008-02-01
Hi experts,

with the following source code, I try to print an ASCII text file on my printer:

procedure TfrmPrintFile.Button3Click(Sender: TObject);

var filename: string;
    printer:textfile;
   
begin
  if opendialog1.execute then
   filename:=opendialog1.filename;
  assignPrn (printer);
  {$I-} rewrite (printer); {$I+}
  if ioresult<>0 then halt;
  while not eof (printer)
   do writeln (printer,filename);
  closefile(printer);
end;



Unfortunately Delphi complains about an  I/O error Nr. 104

in the line:

while not eof (printer)

What am I doing wrong here?

With kind regards

Christian

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Commented:
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Author

Commented:
Dear Matvey,

I basically know how one can print a file. But I don't know my error in the posted source. So can you please review my code and stick please a little bit closer at it with your reply? (You did not explain to me the error 104). In this situation I don't need to set a specific font. A simple printout will perfectly meet my expectations. Moreover I don't know at program start what I want to print. This decision is made by the user during run time of the program. This is the reason why I have to open a file and send its content to the printer. In my specific situation I can't send a certain string to the printer- as you do it in your sample code- because the concrete content of the strings are not known at program start.

So please, try it again.

With kind regards

Christian



Commented:
Hi. Your code produces the error on the "EOF(printer)" statement. It happends because the printer isn't concidered a readable device, so you can read it to find it's end. Therefore you have to avoid this statement.
To print your file you write something like this:

var filename, s: string;
    printer, t: textfile;
begin
  if opendialog1.execute then
    filename:=opendialog1.filename;
  try
    assignPrn(printer);
    rewrite(printer);
    reset(t, FileName);
    while not eof(t) do begin
      readln(t, s);
      writeln(printer, s);
    end;
  finally
    closefile(t);
    closefile(printer);
  end;
end;

-Sorry I was unclear and not specific.
All the best,
--Matvey

Author

Commented:
Dear Matvey,

thank you for reviewing my code concerning file printing. Now all works perfectly
as I like it.
Please excuse my unclear question. Of course it was well intended from
you when you provided me with details about font settings. I did not tell
you that I prefer a spartanic printout in this specific case.

With kind regards.

Christian

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