win32 - ReadDirectoryChangesW的使用
任务:创建一个进程,并在进程内创建一个文本,再创建另一个进程来监控第一个进程内的文本变化
//Process 1 #include <windows.h> #include <iostream> int wmain(int argc, wchar_t* argv[]) { std::string buffer; while (1) { std::cin >> buffer; HANDLE hFile = CreateFile(L"log.txt", FILE_APPEND_DATA, FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0); DWORD written = 0; WriteFile(hFile, buffer.c_str(), buffer.size(), &written, NULL); CloseHandle(hFile); } return 0; }
//Process 2 #include <windows.h> #include <iostream> int wmain(int argc, wchar_t* argv[]) { DWORD returned = 0; DWORD dwOffset = 0; FILE_NOTIFY_INFORMATION* pInfo = NULL; HANDLE hFile = CreateFile(L"Directory of log.txt", GENERIC_READ, FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS, 0); while (1) { BYTE szBuffer[1024] = { 0 }; ReadDirectoryChangesW(hFile, szBuffer, sizeof(szBuffer), false, FILE_NOTIFY_CHANGE_SIZE, &returned, NULL, NULL); do { pInfo = (FILE_NOTIFY_INFORMATION*)&szBuffer[dwOffset]; if (wcscmp(pInfo->FileName, L"log.txt") == 0) { HANDLE hFile = CreateFile(L"path\\log.txt", FILE_APPEND_DATA, 0, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0); DWORD size = GetFileSize(hFile, NULL); std::cout << "File Size: " << size << std::endl; CloseHandle(hFile); } dwOffset += pInfo->NextEntryOffset; } while (pInfo->NextEntryOffset != 0); } return 0; }
相关:https://stackoverflow.com/questions/63620862/using-file-as-a-mutex-with-createfile/63627936#63627936