[Python-Dev] Python 2.5.1

[Alexey Borzenkov]

On 5/1/07, "Martin v. Löwis" <martin at v.loewis.de> wrote:
> > After doing some research I found that it seems to be impossible to
> > use CreateFile for a file that doesn't have SHARE_READ. I played with
> > different combinations and with FLAG_BACKUP_SEMANTICS and nothing
> > helped. However on Windows there's still a possibility to read
> > attributes: use FindFirstFile. _WIN32_FIND_DATA structure seems to
> > have all the necessary fields (attributes, file times, size and
> > full/short filename), and FindFirstFile doesn't care about sharing at
> > all...
> So what about GetFileAttributesEx? What are the conditions under which
> I can successfully invoke it?

Seems to have the same problems as with CreateFile(...):

// 1.cc
#include <windows.h>
#include <stdio.h>

int main(int argc, char** argv)
{
	WIN32_FILE_ATTRIBUTE_DATA data;
	if(!GetFileAttributesEx("pagefile.sys", GetFileExInfoStandard, (LPVOID)&data))
	{
		char buffer[1024];
		FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(), 0,
buffer, 1024, NULL);
		printf("Error %d: %s\n", GetLastError(), buffer);
		return 1;
	}
	printf("Success\n");
	return 0;
}

// 2.cc
#include <windows.h>
#include <stdio.h>

int main(int argc, char** argv)
{
	WIN32_FIND_DATA data;
	if(INVALID_HANDLE_VALUE == FindFirstFile("pagefile.sys", &data))
	{
		char buffer[1024];
		FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(), 0,
buffer, 1024, NULL);
		printf("Error %d: %s\n", GetLastError(), buffer);
		return 1;
	}
	printf("Success\n");
	return 0;
}

C:\>C:\3\1.exe
Error 32: The process cannot access the file because it is being used
by another process.

C:\>C:\3\2.exe
Success