I am using resource for my update program. i was compile resource with brcc32 than compile updater program. when updater program run its self check everything and write or update with new ones. but about this process you have to right write,delete privileges at where your programs run.
i am adding a sample code to below.
file exe.rc
newprog RCDATA Application.exe
file makeres.bat
brcc32 exe.rc
file updater.dpr
{$R exe.res}
unit file and procedures
procedure ExtractRes(resname,fname,ext:string);
var
rStream:TResourceStream;
fStream:TFileStream;
fNamex:string;
begin
fNamex:=ExtractFilePath(Application.ExeName)+fname+'.'+ext;
if not fileExists(fnamex) then
begin
try
rStream:=tresourcestream.Create(hinstance,ResName,RT_rcDATA);
fStream := TFileStream.Create(fnamex, fmCreate);
fStream.CopyFrom(rStream, 0);
finally
rStream.Free;
fstream.Free;
end;
end;
end;
procedure TForm1.Timer1Timer(Sender: TObject);
var
apath:string;
begin
if Timer1.Enabled then
Timer1.Enabled:=false;
apath:=ExtractFilePath(Application.ExeName);
lblMesg.Caption:='Backup old version';
Application.ProcessMessages;
if FileExists(apath+'Application_old.bak') then
DeleteFile(apath+'Application_old.bak') ;
while FileExists(apath+'Application.exe') do
begin
RenameFile(apath + 'Application.exe', apath + 'Application_old.bak');
sleep(1);
if FileExists(apath+'Application.exe') then
begin
lblMesg.Caption:='It seems application still running. Waiting for end';
if FileExists(apath+'Application_old.bak') then
DeleteFile(apath+'Application_old.bak');
DeleteFile(apath+'Application.exe');
end;
Application.ProcessMessages;
end;
lblMesg.Caption:='Creating New Version..';
Application.ProcessMessages;
ExtractRes('Application','Application','exe');
lblMesg.Caption:='Running New Version...';
Application.ProcessMessages;
WinExec(pchar(apath+'Application.exe'),sw_show);
Application.ProcessMessages;
Halt;
end;
i think this can help your 1,2,3 question. For 4 you can extend code.