I did a button with followed code:
procedure TForm1.Button3Click(Sender: TObject);
var
S: TStringList;
M: TMemoryStream;
P: TProcess;
n: LongInt;
BytesRead: LongInt;
LZumZerlegen: String;
LErgebnis: TStringlist;
I, i1, i2 : integer ;
begin
combobox1.clear;
combobox2.clear;
listbox1.clear;
listbox2.clear;
// n := 0;
// listbox1.clear;
// listbox2.clear;
combobox1.text := 'updating ... ';
combobox2.text :='updating ... ';
memo2.lines.add(DateToStr(Date) + '-' +TimeToStr(Time) + ' - get HDD table') ;
// We cannot use poWaitOnExit here since we don't
// know the size of the output. On Linux the size of the
// output pipe is 2 kB. If the output data is more, we
// need to read the data. This isn't possible since we are
// waiting. So we get a deadlock here.
//
// A temp Memorystream is used to buffer the output
M := TMemoryStream.Create;
BytesRead := 0;
form1.memo2.lines.add('-- create process --');
P := TProcess.Create(nil);
P.CommandLine := 'fdisk -l';
P.Options := [poUsePipes];
form1.memo2.lines.add('-- executing --');
P.Execute;
while P.Running= true do
begin
sleep (250);
Application.ProcessMessages;
// make sure we have room
form1.memo2.lines.add('-- make sure we have room --');
M.SetSize(BytesRead + READ_BYTES);
// try reading it
form1.memo2.lines.add('-- try reading it --');
n := P.Output.Read((M.Memory + BytesRead)^, READ_BYTES);
if n > 0
then begin
form1.memo2.lines.add('-- n > 0 --');
Inc(BytesRead, n);
Write('.')
end
else begin
// no data, wait 100 ms
form1.memo2.lines.add('-- no data --');
Sleep(100);
end;
end;
// read last part
repeat
// make sure we have room
M.SetSize(BytesRead + READ_BYTES);
// try reading it
form1.memo2.lines.add('-- try reading it 2 --');
n := P.Output.Read((M.Memory + BytesRead)^, READ_BYTES);
if n > 0
then begin
form1.memo2.lines.add('-- n > 0 (2) --');
Inc(BytesRead, n);
Write('.');
end;
until n <= 0;
if BytesRead > 0 then WriteLn;
M.SetSize(BytesRead);
form1.memo2.lines.add('-- executed --');
S := TStringList.Create;
S.LoadFromStream(M);
form1.memo2.lines.add('-- linecount = ' + inttostr(S.Count) + ' --');
for n := 0 to S.Count - 1 do
begin
form1. listbox2.items.add(S[n]);
end;
form1.memo2.lines.add('-- end --');
S.clear;
M.clear;
S.Free;
P.Free;
M.Free;
memo2.lines.add(DateToStr(Date) + '-' +TimeToStr(Time) + ' - readout HDD table') ;
for i := 0 to listbox2.items.count -1 do
begin
if (Pos('dev/', listbox2.items[i]) > 0) then
begin
if (Pos(':', listbox2.items[i]) > 0) or (Pos('xtended', listbox2.items[i]) > 0)
then
begin
// nothing
end
else
begin
listbox1.items.add(listbox2.items[i]);
end;
end;
end;
for i1 := 0 to listbox1.items.count -1 do
begin
LZumZerlegen := listbox1.items[i1];
LErgebnis := TStringlist.Create;
splitString(LZumZerlegen, ' ', LErgebnis);
if LErgebnis[LErgebnis.count -1] = 'swap' then
begin
combobox2.items.add(LErgebnis[0] + ' - ' + LErgebnis[LErgebnis.count -1]);
end
else
begin
combobox1.items.add(LErgebnis[0] + ' - ' + LErgebnis[LErgebnis.count -1]);
end;
// listbox3.items.add (LErgebnis[0] + ' - ' + LErgebnis[LErgebnis.count -1]);
LErgebnis.Free;
end;
if combobox1.itemindex = -1 then combobox1.itemindex := 0;
if combobox2.itemindex = -1 then combobox2.itemindex := 0;
memo2.lines.add(DateToStr(Date) + '-' +TimeToStr(Time) + ' - get HDD table - done') ;
button1.enabled := true;
end;
When I click it the first time I get this in the log:
12-3-07-19:47 - Installer started
12-3-07-19:47 - get HDD table
-- create process --
-- executing --
-- make sure we have room --
-- try reading it --
-- n > 0 --
-- make sure we have room --
-- try reading it --
-- no data --
-- try reading it 2 --
-- executed --
-- linecount = 21 --
-- end --
12-3-07-19:47 - readout HDD table
12-3-07-19:47 - get HDD table - done
But when I click the button the second time I only get this in the log:
12-3-07-19:47 - get HDD table
12-3-07-19:47 - readout HDD table
12-3-07-19:47 - get HDD table - done
My question is now: why ???
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