// Watch the directory for file creation and deletion. dwChangeHandles[0] = FindFirstChangeNotification( lpDir, // directory to watch FALSE, // do not watch subtree FILE_NOTIFY_CHANGE_FILE_NAME); // watch file name changes
if (dwChangeHandles[0] == INVALID_HANDLE_VALUE) { printf("\n ERROR: FindFirstChangeNotification function failed.\n"); ExitProcess(GetLastError()); }
// Watch the subtree for directory creation and deletion. dwChangeHandles[1] = FindFirstChangeNotification( lpDrive, // directory to watch TRUE, // watch the subtree FILE_NOTIFY_CHANGE_DIR_NAME); // watch dir name changes
if (dwChangeHandles[1] == INVALID_HANDLE_VALUE) { printf("\n ERROR: FindFirstChangeNotification function failed.\n"); ExitProcess(GetLastError()); } // Make a final validation check on our handles. if ((dwChangeHandles[0] == NULL) || (dwChangeHandles[1] == NULL)) { printf("\n ERROR: Unexpected NULL from FindFirstChangeNotification.\n"); ExitProcess(GetLastError()); }// Change notification is set. Now wait on both notification // handles and refresh accordingly. while (TRUE) { // Wait for notification. printf("\nWaiting for notification...\n"); dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles, FALSE, INFINITE);
switch (dwWaitStatus) { case WAIT_OBJECT_0:
// A file was created, renamed, or deleted in the directory. // Refresh this directory and restart the notification. RefreshDirectory(lpDir); if ( FindNextChangeNotification(dwChangeHandles[0]) == FALSE ) { printf("\n ERROR: FindNextChangeNotification function failed.\n"); ExitProcess(GetLastError()); } break;
case WAIT_OBJECT_0 + 1:
// A directory was created, renamed, or deleted. // Refresh the tree and restart the notification. RefreshTree(lpDrive); if (FindNextChangeNotification(dwChangeHandles[1]) == FALSE ) { printf("\n ERROR: FindNextChangeNotification function failed.\n"); ExitProcess(GetLastError()); } break;
case WAIT_TIMEOUT: // A time-out occurred. This would happen if some value other // than INFINITE is used in the Wait call and no changes occur. // In a single-threaded environment, you might not want an // INFINITE wait.
printf("\nNo changes in the time-out period.\n"); break; default: printf("\n ERROR: Unhandled dwWaitStatus.\n"); ExitProcess(GetLastError()); break; } } }void RefreshDirectory(LPTSTR lpDir) { // This is where you might place code to refresh your // directory listing, but not the subtree because it // would not be necessary. _tprintf(TEXT("Directory (%s) changed.\n"), lpDir); }void RefreshTree(LPTSTR lpDrive) { // This is where you might place code to refresh your // directory listing, including the subtree. _tprintf(TEXT("Directory tree (%s) changed.\n"), lpDrive); }
FindNextChangeNotification()
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <tchar.h>void RefreshDirectory(LPTSTR);
void RefreshTree(LPTSTR);
void WatchDirectory(LPTSTR);void _tmain(int argc, TCHAR *argv[])
{
if(argc != 2)
{
_tprintf(TEXT("Usage: %s <dir>\n"), argv[0]);
return;
} WatchDirectory(argv[1]);
}void WatchDirectory(LPTSTR lpDir)
{
DWORD dwWaitStatus;
HANDLE dwChangeHandles[2];
TCHAR lpDrive[4];
TCHAR lpFile[_MAX_FNAME];
TCHAR lpExt[_MAX_EXT]; _tsplitpath_s(lpDir, lpDrive, 4, NULL, 0, lpFile, _MAX_FNAME, lpExt, _MAX_EXT); lpDrive[2] = (TCHAR)'\\';
lpDrive[3] = (TCHAR)'\0';
// Watch the directory for file creation and deletion.
dwChangeHandles[0] = FindFirstChangeNotification(
lpDir, // directory to watch
FALSE, // do not watch subtree
FILE_NOTIFY_CHANGE_FILE_NAME); // watch file name changes
if (dwChangeHandles[0] == INVALID_HANDLE_VALUE)
{
printf("\n ERROR: FindFirstChangeNotification function failed.\n");
ExitProcess(GetLastError());
}
// Watch the subtree for directory creation and deletion.
dwChangeHandles[1] = FindFirstChangeNotification(
lpDrive, // directory to watch
TRUE, // watch the subtree
FILE_NOTIFY_CHANGE_DIR_NAME); // watch dir name changes
if (dwChangeHandles[1] == INVALID_HANDLE_VALUE)
{
printf("\n ERROR: FindFirstChangeNotification function failed.\n");
ExitProcess(GetLastError());
}
// Make a final validation check on our handles.
if ((dwChangeHandles[0] == NULL) || (dwChangeHandles[1] == NULL))
{
printf("\n ERROR: Unexpected NULL from FindFirstChangeNotification.\n");
ExitProcess(GetLastError());
}// Change notification is set. Now wait on both notification
// handles and refresh accordingly.
while (TRUE)
{
// Wait for notification.
printf("\nWaiting for notification...\n"); dwWaitStatus = WaitForMultipleObjects(2, dwChangeHandles,
FALSE, INFINITE);
switch (dwWaitStatus)
{
case WAIT_OBJECT_0:
// A file was created, renamed, or deleted in the directory.
// Refresh this directory and restart the notification.
RefreshDirectory(lpDir);
if ( FindNextChangeNotification(dwChangeHandles[0]) == FALSE )
{
printf("\n ERROR: FindNextChangeNotification function failed.\n");
ExitProcess(GetLastError());
}
break;
case WAIT_OBJECT_0 + 1:
// A directory was created, renamed, or deleted.
// Refresh the tree and restart the notification.
RefreshTree(lpDrive);
if (FindNextChangeNotification(dwChangeHandles[1]) == FALSE )
{
printf("\n ERROR: FindNextChangeNotification function failed.\n");
ExitProcess(GetLastError());
}
break;
case WAIT_TIMEOUT: // A time-out occurred. This would happen if some value other
// than INFINITE is used in the Wait call and no changes occur.
// In a single-threaded environment, you might not want an
// INFINITE wait.
printf("\nNo changes in the time-out period.\n");
break; default:
printf("\n ERROR: Unhandled dwWaitStatus.\n");
ExitProcess(GetLastError());
break;
}
}
}void RefreshDirectory(LPTSTR lpDir)
{
// This is where you might place code to refresh your
// directory listing, but not the subtree because it
// would not be necessary. _tprintf(TEXT("Directory (%s) changed.\n"), lpDir);
}void RefreshTree(LPTSTR lpDrive)
{
// This is where you might place code to refresh your
// directory listing, including the subtree. _tprintf(TEXT("Directory tree (%s) changed.\n"), lpDrive);
}