how to eliminate extraneous console output after ctrl-c in Windows? - windows

Question

When pressing Ctrl-c there is almost always additional output. I'd like to ensure that after receiving the Ctrl-c the program doesn't show anything other than possibly "^C".
I found what is mostly the same question but, it was for Linux and my attempts to "port" the solution from Linux to Windows have not succeeded.
At this point, I'm out of things to try and can use some help, which I will definitely appreciate. Thank you.
The short example program below suffers from that problem.
{$APPTYPE CONSOLE}
program _SetConsoleCtrlHandler;
uses
Windows,
SysUtils
;
function CtrlHandler(CtrlType : DWORD) : BOOL; stdcall;
begin
result := FALSE;
case CtrlType of
CTRL_C_EVENT,
CTRL_BREAK_EVENT:
begin
result := TRUE;
ExitProcess(7);
end;
end;
end;
var
s : shortstring;
begin
SetConsoleCtrlHandler(#CtrlHandler, TRUE);
while TRUE do
begin
write('press <ctrl-c> to end this program : ');
readln(s);
end;
end.

Answer 1

The way I usually do this is to have a separate unit that is signaled and a simple wait, like the following. In the main console project you call WaitForCtrlC instead of Readln(). You could also use a TEvent and wait on the event instead of looping, like I show in this example:
uses
{$IFDEF LINUX}
Posix.Signal,
{$ENDIF}
{$IFDEF MSWINDOWS}
Windows,
{$ENDIF}
SysUtils;
procedure WaitForCtrlC;
implementation
var
Control_C: Boolean = False;
{$IFDEF MSWINDOWS}
function ConsoleCtrlHandler(dwCtrlType: DWORD): BOOL; stdcall;
begin
if (dwCtrlType = CTRL_C_EVENT) then
Control_C := True;
Result := True;
end;
{$ENDIF}
{$IFDEF LINUX}
var
sigIntHandler: sigaction_t;
procedure SigHandler(SigNum: Integer); cdecl;
begin
Control_C := True;
end;
{$ENDIF}
procedure WaitForCtrlC;
begin
while not Control_C do
Sleep(25);
end;
initialization
{$IFDEF MSWINDOWS}
Windows.SetConsoleCtrlHandler(#ConsoleCtrlHandler, True);
{$ENDIF}
{$IFDEF LINUX}
sigIntHandler._u.sa_handler := #SigHandler;
sigemptyset(sigIntHandler.sa_mask);
sigIntHandler.sa_flags := 0;
sigaction(SIGINT, #sigIntHandler, nil);
{$ENDIF}