Can I send a ctrl-C (SIGINT) to an application on Windows?

Question

I have (in the past) written cross-platform (Windows/Unix) applications which, when started from the command line, handled a user-typed Ctrl-C combination in the same way (i.e. to terminate the application cleanly).

Is it possible on Windows to send a Ctrl-C/SIGINT/equivalent to a process from another (unrelated) process to request that it terminate cleanly (giving it an opportunity to tidy up resources etc.)?

Answer 1

I have done some research around this topic, which turned out to be more popular than I anticipated. KindDragon's reply was one of the pivotal points.

I wrote a longer blog post on the topic and created a working demo program, which demonstrates using this type of system to close a command line application in a couple of nice fashions. That post also lists external links that I used in my research.

In short, those demo programs do the following:

• Start a program with a visible window using .Net, hide with pinvoke, run for 6 seconds, show with pinvoke, stop with .Net.
• Start a program without a window using .Net, run for 6 seconds, stop by attaching console and issuing ConsoleCtrlEvent

Edit: The amended solution from @KindDragon for those who are interested in the code here and now. If you plan to start other programs after stopping the first one, you should re-enable CTRL+C handling, otherwise the next process will inherit the parent's disabled state and will not respond to CTRL+C.

[DllImport("kernel32.dll", SetLastError = true)] static extern bool AttachConsole(uint dwProcessId);  [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)] static extern bool FreeConsole();  [DllImport("kernel32.dll")] static extern bool SetConsoleCtrlHandler(ConsoleCtrlDelegate HandlerRoutine, bool Add);  delegate bool ConsoleCtrlDelegate(CtrlTypes CtrlType);  // Enumerated type for the control messages sent to the handler routine enum CtrlTypes : uint {     CTRL_C_EVENT = 0,     CTRL_BREAK_EVENT,     CTRL_CLOSE_EVENT,     CTRL_LOGOFF_EVENT = 5,     CTRL_SHUTDOWN_EVENT }  [DllImport("kernel32.dll")] [return: MarshalAs(UnmanagedType.Bool)] private static extern bool GenerateConsoleCtrlEvent(CtrlTypes dwCtrlEvent, uint dwProcessGroupId);  public void StopProgram(Process proc) {     //This does not require the console window to be visible.     if (AttachConsole((uint)proc.Id))     {     // Disable Ctrl-C handling for our program     SetConsoleCtrlHandler(null, true);      GenerateConsoleCtrlEvent(CtrlTypes.CTRL_C_EVENT, 0);      //Moved this command up on suggestion from Timothy Jannace (see comments below)     FreeConsole();                      // Must wait here. If we don't and re-enable Ctrl-C     // handling below too fast, we might terminate ourselves.     proc.WaitForExit(2000);                      //Re-enable Ctrl-C handling or any subsequently started     //programs will inherit the disabled state.     SetConsoleCtrlHandler(null, false);      } } 

Also, plan for a contingency solution if AttachConsole() or the sent signal should fail, for instance sleeping then this:

if (!proc.HasExited) {     try     {     proc.Kill();     }     catch (InvalidOperationException e){} }