Starting another application while terminating the actual one

[99Percent]

How do you begin execution on another application while simultaneously terminating the actual program? I need to do this so that the other application can delete the executable file.

Sorry if this is explained in the wiki, but the wiki is down (yet again).

[Zoran]

I don't think that it can be done. However, what you intend may be done by using another program which starts the first application, then after closing it, deletes it.

As I understand, that is what the startlazarus program does with lazarus (after you rebuild the IDE, it terminates lazarus process, deletes lazarus exe file and replaces it with the newly created one, then starts it).

[Leledumbo]

You can, try this:

Code: [Select]

with TProcess.Create(nil) do
  try
    CommandLine := 'Replace with your program';
    Options := [];
    Execute;
  finally
    Free;
  end;


[ivan17]

to quote the wiki

The simplest way if you don't need pipes or any form of control is to simply use SysUtils.ExecuteProcess('/full/path/to/binary',['arg1','arg2']);

so just do that and terminate your application.

meanwhile second application (without forms but non-console) should do this:

Code: [Select]

begin
  while DeleteFile('app1') = false do Sleep(500);  // if can't delete (locked), wait half a sec and try again
end.


see that there is only one instance of main program active.

[Leledumbo]

so just do that and terminate your application.

You can't, AFAIK SysUtils.ExecuteProcess blocks program execution.

[ivan17]

You can't, AFAIK SysUtils.ExecuteProcess blocks program execution.

my bad, never really used that one; ok then TProcess without poWaitOnExit in options.