rdp · February 28, 2025 13:15 · Oct 21, 2019 · Jan 30, 2019 · Jan 29, 2019 · Jun 25, 2015
diff --git a/send_ctrl_c.c b/send_ctrl_c.c
@@ -37,7 +37,7 @@ void logLastError()
 void sendCtrlC(int pid)
 {
   //This does not require the console window to be visible.
-  printf("sending ctrl+c to pid %d", pid); // have to log here or we'll be sending it to the other console with printf [!] XXX could maybe duplicate descriptors first or some odd...oh well.
+  printf("sending ctrl+c to pid %d", pid); // if we want to log anything at all, have to log here or we'll be sending it to the other console with printf [!] XXX could maybe duplicate descriptors first or some odd...oh well.
   FreeConsole(); // free ourselves from our current console, in case we're being run from a cmd.exe otherwise can't attach to another (at most one).  And we probably are...if it fails because we don't have one, that's OK too.
   if (AttachConsole(pid))
   {
@@ -48,7 +48,7 @@ void sendCtrlC(int pid)
     // could also send it *another* ctrl_c_event, for instance if you're trying to interrupt something in a batch file and it has that ugly "Batch file interrupted, continue [y/n]" [?]
   }
   else {
-      logLastError();
+      logLastError(); // failure, PID might no longer exist, show a GUI error window
   }
 }
 

diff --git a/send_ctrl_c.cpp → send_ctrl_c.c b/send_ctrl_c.cpp → send_ctrl_c.c
diff --git a/send_ctrl_c.cpp b/send_ctrl_c.cpp
@@ -44,7 +44,7 @@ void sendCtrlC(int pid)
     // Disable Ctrl-C handling for our own program, so we don't "kill" ourselves on accident...though that might not hurt currently...
     SetConsoleCtrlHandler(NULL, true);
     GenerateConsoleCtrlEvent(CTRL_C_EVENT , 0); // these get sent to every process attached to this console, FWIW...
-    // TODO could wait here for process to exit, hard kill it after a pause, etc. see http://stackoverflow.com/a/31020562/32453
+    // TODO could wait here for process to exit, hard kill it after a sufficient wait, etc. see http://stackoverflow.com/a/31020562/32453
     // could also send it *another* ctrl_c_event, for instance if you're trying to interrupt something in a batch file and it has that ugly "Batch file interrupted, continue [y/n]" [?]
   }
   else {

diff --git a/send_ctrl_c.cpp b/send_ctrl_c.cpp
@@ -1,3 +1,6 @@
+// attribution: http://stackoverflow.com/a/15281070/32453
+// you can compile this with gcc [mingw or mingw-w64] and probably other compilers as well
+
 #include <stdlib.h> // NULL
 #include <stdbool.h> // false
 #include <windows.h> // AttachConsole, CTRL_C_EVENT, etc.
@@ -35,14 +38,14 @@ void sendCtrlC(int pid)
 {
   //This does not require the console window to be visible.
   printf("sending ctrl+c to pid %d", pid); // have to log here or we'll be sending it to the other console with printf [!] XXX could maybe duplicate descriptors first or some odd...oh well.
-  FreeConsole(); // free current console, in case we're being run from a cmd.exe otherwise can't attach to another (at most one).  And we probably are...if it fails because we don't have one, that's OK too.
+  FreeConsole(); // free ourselves from our current console, in case we're being run from a cmd.exe otherwise can't attach to another (at most one).  And we probably are...if it fails because we don't have one, that's OK too.
   if (AttachConsole(pid))
   {
-    // Disable Ctrl-C handling for our own program, so we don't "kill" ourselves on accident...
+    // Disable Ctrl-C handling for our own program, so we don't "kill" ourselves on accident...though that might not hurt currently...
     SetConsoleCtrlHandler(NULL, true);
     GenerateConsoleCtrlEvent(CTRL_C_EVENT , 0); // these get sent to every process attached to this console, FWIW...
-    // could also send CTRL_BREAK_EVENT
-    // TODO could wait here for process to exit, hard kill it (TerminateProcess) after a pause (pause info: http://stackoverflow.com/a/31020562/32453)
+    // TODO could wait here for process to exit, hard kill it after a pause, etc. see http://stackoverflow.com/a/31020562/32453
+    // could also send it *another* ctrl_c_event, for instance if you're trying to interrupt something in a batch file and it has that ugly "Batch file interrupted, continue [y/n]" [?]
   }
   else {
       logLastError();

diff --git a/send_ctrl_c.cpp b/send_ctrl_c.cpp
@@ -41,6 +41,7 @@ void sendCtrlC(int pid)
     // Disable Ctrl-C handling for our own program, so we don't "kill" ourselves on accident...
     SetConsoleCtrlHandler(NULL, true);
     GenerateConsoleCtrlEvent(CTRL_C_EVENT , 0); // these get sent to every process attached to this console, FWIW...
+    // could also send CTRL_BREAK_EVENT
     // TODO could wait here for process to exit, hard kill it (TerminateProcess) after a pause (pause info: http://stackoverflow.com/a/31020562/32453)
   }
   else {

diff --git a/send_ctrl_c.cpp b/send_ctrl_c.cpp
@@ -1,4 +1,3 @@
-
 #include <stdlib.h> // NULL
 #include <stdbool.h> // false
 #include <windows.h> // AttachConsole, CTRL_C_EVENT, etc.
@@ -42,7 +41,7 @@ void sendCtrlC(int pid)
     // Disable Ctrl-C handling for our own program, so we don't "kill" ourselves on accident...
     SetConsoleCtrlHandler(NULL, true);
     GenerateConsoleCtrlEvent(CTRL_C_EVENT , 0); // these get sent to every process attached to this console, FWIW...
-    // TODO could wait here for process to exit, hard kill it after a pause, etc. see http://stackoverflow.com/a/31020562/32453
+    // TODO could wait here for process to exit, hard kill it (TerminateProcess) after a pause (pause info: http://stackoverflow.com/a/31020562/32453)
   }
   else {
       logLastError();

diff --git a/send_ctrl_c.cpp b/send_ctrl_c.cpp
@@ -41,9 +41,8 @@ void sendCtrlC(int pid)
   {
     // Disable Ctrl-C handling for our own program, so we don't "kill" ourselves on accident...
     SetConsoleCtrlHandler(NULL, true);
-    GenerateConsoleCtrlEvent(CTRL_C_EVENT, 0); // these get sent to every process attached to this console, FWIW...
-    // TODO could wait here for process to exit, hard kill it, etc.
-    // don't know how to do that, so...just exit this program, basically.
+    GenerateConsoleCtrlEvent(CTRL_C_EVENT , 0); // these get sent to every process attached to this console, FWIW...
+    // TODO could wait here for process to exit, hard kill it after a pause, etc. see http://stackoverflow.com/a/31020562/32453
   }
   else {
       logLastError();

diff --git a/send_ctrl_c.cpp b/send_ctrl_c.cpp
@@ -0,0 +1,61 @@
+
+#include <stdlib.h> // NULL
+#include <stdbool.h> // false
+#include <windows.h> // AttachConsole, CTRL_C_EVENT, etc.
+#include <stdio.h> // printf
+
+#include <strsafe.h>
+void logLastError() 
+{ 
+    LPTSTR errorText = NULL;
+
+    FormatMessage(
+       // use system message tables to retrieve error text
+       FORMAT_MESSAGE_FROM_SYSTEM
+       // allocate buffer on local heap for error text
+       |FORMAT_MESSAGE_ALLOCATE_BUFFER
+       // Important! will fail otherwise, since we're not 
+       // (and CANNOT) pass insertion parameters
+       |FORMAT_MESSAGE_IGNORE_INSERTS,  
+       NULL,    // unused with FORMAT_MESSAGE_FROM_SYSTEM
+       GetLastError(),
+       MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+       (LPTSTR)&errorText,  // output 
+       0, // minimum size for output buffer
+       NULL);   // arguments - see note 
+
+    if ( NULL != errorText )
+    {
+       printf("failure: %s", errorText);
+       LocalFree(errorText);
+       errorText = NULL;
+    }
+}
+
+void sendCtrlC(int pid)
+{
+  //This does not require the console window to be visible.
+  printf("sending ctrl+c to pid %d", pid); // have to log here or we'll be sending it to the other console with printf [!] XXX could maybe duplicate descriptors first or some odd...oh well.
+  FreeConsole(); // free current console, in case we're being run from a cmd.exe otherwise can't attach to another (at most one).  And we probably are...if it fails because we don't have one, that's OK too.
+  if (AttachConsole(pid))
+  {
+    // Disable Ctrl-C handling for our own program, so we don't "kill" ourselves on accident...
+    SetConsoleCtrlHandler(NULL, true);
+    GenerateConsoleCtrlEvent(CTRL_C_EVENT, 0); // these get sent to every process attached to this console, FWIW...
+    // TODO could wait here for process to exit, hard kill it, etc.
+    // don't know how to do that, so...just exit this program, basically.
+  }
+  else {
+      logLastError();
+  }
+}
+
+int main( int argc, const char* argv[] ) {
+    // assume they know the pid...
+    if (argc != 2) {
+        printf("syntax: pid");
+        return 1;
+    }
+    int pid = atoi(argv[1]);
+    sendCtrlC(pid);
+}