LLM wrote this.

fs_watch.c

#define _CRT_SECURE_NO_WARNINGS
#include <Windows.h>
#include <stdio.h>

#define BUFFER_SIZE 4096

int main(int argc, char *argv[]) {
  HANDLE hDir;
  DWORD bytesReturned;
  char buffer[BUFFER_SIZE];
  FILE_NOTIFY_INFORMATION *pNotify;
  WCHAR fileName[MAX_PATH];
  WCHAR fullPath[MAX_PATH];
  WCHAR dirPathW[MAX_PATH];
  WIN32_FILE_ATTRIBUTE_DATA fileInfo;
  SYSTEMTIME st;
  const char *dirPath = (argc > 1) ? argv[1] : ".";

  hDir = CreateFileA(dirPath, FILE_LIST_DIRECTORY,
                     FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
                     NULL, OPEN_EXISTING,
                     FILE_FLAG_BACKUP_SEMANTICS, NULL);

  if (hDir == INVALID_HANDLE_VALUE) {
    printf("Failed to open directory: %s (error %lu)\n", dirPath, GetLastError());
    return 1;
  }

  printf("Watching directory: %s\n", dirPath);
  printf("Press Ctrl+C to exit...\n\n");

  // Convert directory path to wide string for later use
  MultiByteToWideChar(CP_ACP, 0, dirPath, -1, dirPathW, MAX_PATH);

  while (1) {
    if (!ReadDirectoryChangesW(hDir, buffer, BUFFER_SIZE, TRUE,
                                FILE_NOTIFY_CHANGE_FILE_NAME |
                                FILE_NOTIFY_CHANGE_DIR_NAME |
                                FILE_NOTIFY_CHANGE_ATTRIBUTES |
                                FILE_NOTIFY_CHANGE_SIZE |
                                FILE_NOTIFY_CHANGE_LAST_WRITE |
                                FILE_NOTIFY_CHANGE_CREATION,
                                &bytesReturned, NULL, NULL)) {
      printf("ReadDirectoryChangesW failed: %lu\n", GetLastError());
      break;
    }

    pNotify = (FILE_NOTIFY_INFORMATION *)buffer;
    while (1) {
      wcsncpy(fileName, pNotify->FileName, pNotify->FileNameLength / sizeof(WCHAR));
      fileName[pNotify->FileNameLength / sizeof(WCHAR)] = L'\0';

      printf("Action: ");
      switch (pNotify->Action) {
        case FILE_ACTION_ADDED:
          printf("ADDED");
          break;
        case FILE_ACTION_REMOVED:
          printf("REMOVED");
          break;
        case FILE_ACTION_MODIFIED:
          printf("MODIFIED");
          break;
        case FILE_ACTION_RENAMED_OLD_NAME:
          printf("RENAMED_OLD_NAME");
          break;
        case FILE_ACTION_RENAMED_NEW_NAME:
          printf("RENAMED_NEW_NAME");
          break;
        default:
          printf("UNKNOWN");
      }
      printf(" - File: %ls", fileName);

      // Construct full path and get file info
      swprintf(fullPath, MAX_PATH, L"%ls\\%ls", dirPathW, fileName);
      if (GetFileAttributesExW(fullPath, GetFileExInfoStandard, &fileInfo)) {
        // Convert file time to system time
        FILETIME localTime;
        FileTimeToLocalFileTime(&fileInfo.ftLastWriteTime, &localTime);
        FileTimeToSystemTime(&localTime, &st);

        // Calculate file size
        ULONGLONG fileSize = ((ULONGLONG)fileInfo.nFileSizeHigh << 32) | fileInfo.nFileSizeLow;

        printf(" - Size: %llu bytes - Modified: %04d-%02d-%02d %02d:%02d:%02d.%03d\n",
               fileSize, st.wYear, st.wMonth, st.wDay,
               st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
      } else {
        printf(" - (Unable to get file info)\n");
      }

      if (pNotify->NextEntryOffset == 0)
        break;
      pNotify = (FILE_NOTIFY_INFORMATION *)((char *)pNotify + pNotify->NextEntryOffset);
    }
  }

  CloseHandle(hDir);
  return 0;
}