test.c

#include <direct.h>
#include <stdio.h>
#include <windows.h>

int
main(int argc, char *argv[])
{
	printf("Creating file foo.txt...\n");
	HANDLE file = CreateFile("foo.txt", GENERIC_WRITE,
							 FILE_SHARE_DELETE, NULL,
							 CREATE_NEW, FILE_ATTRIBUTE_NORMAL, NULL);
	if (file == INVALID_HANDLE_VALUE)
	{
		printf("Failed, error = %d, errno = %d (%s).\n", GetLastError(), errno, strerror(errno));
		exit(1);
	}

	printf("Creating file bar.txt...\n");
	HANDLE file2 = CreateFile("bar.txt", GENERIC_WRITE,
							 FILE_SHARE_DELETE, NULL,
							 CREATE_NEW, FILE_ATTRIBUTE_NORMAL, NULL);
	if (file2 == INVALID_HANDLE_VALUE)
	{
		printf("Failed, error = %d, errno = %d (%s).\n", GetLastError(), errno, strerror(errno));
		exit(1);
	}

#if 0
	printf("Unlinking bar.txt...\n");
	if (unlink("bar.txt") != 0)
	{
		printf("Failed, error = %d, errno = %d (%s).\n", GetLastError(), errno, strerror(errno));
		exit(1);
	}
	CloseHandle(file);
	CloseHandle(file2);
#endif

#if 0
	/* this doesn't work */
	printf("Renaming foo.txt to bar.txt...\n");
	if (rename("foo.txt", "bar.txt") != 0)
	{
		printf("Failed, error = %d, errno = %d (%s).\n", GetLastError(), errno, strerror(errno));
		exit(1);
	}
#endif

	/* this does work */
	const wchar_t *new_name = L"bar.txt";
	size_t len = wcslen(new_name);
	FILE_RENAME_INFO *rename_info = malloc(sizeof(FILE_RENAME_INFO) + len * sizeof(wchar_t));
	rename_info->Flags = FILE_RENAME_FLAG_POSIX_SEMANTICS;
	rename_info->ReplaceIfExists = TRUE;
	rename_info->RootDirectory = NULL;
	rename_info->FileNameLength = len;
	wmemcpy(rename_info->FileName, new_name, len);
	printf("Performing mysterious SetFileInformationByHandle operation...\n");
	if (SetFileInformationByHandle(file, FileRenameInfoEx, &rename_info, sizeof(FILE_RENAME_INFO) + len * sizeof(wchar_t)))
	{
		printf("Failed, error = %d, errno = %d (%s).\n", GetLastError(), errno, strerror(errno));
		exit(1);
	}

	return 0;
}