simsong
Check whether C++17 can now read raw disk partitions, or if I need to put back in the WIN32-specific code
C++17 has no such support.
But, you can open volumes and physical disks as files in Windows. A physical device path would be like “\.\PhysicalDevice0”. You have to run the program with administrative privileges.
On Oct 10, 2021, at 6:38 PM, Simson L. Garfinkel @.***> wrote:
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The question is, if I open the physical disk as a Windows file, do the C++ intrinsics for getting the file length and seeking in the file work, or do I need to use this code that I've now deleted based on GetDiskGeometry() and ReadFile and Windows handles to read the raw device once it is opened?
I… think… everything works. Let me verify the fseek(end), ftell() behavior.
Sent from my iPhone
On Oct 10, 2021, at 7:53 PM, Simson L. Garfinkel @.***> wrote:
The question is, if I open the physical disk as a Windows file, do the C++ intrinsics for getting the file length and seeking in the file work, or do I need to use this code that I've now deleted based on GetDiskGeometry() and ReadFile and Windows handles to read the raw device once it is opened?
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I'll be double checking! It would be great to get rid of the GetDiskGeometry() stuff.
I wonder whether std::filesystem would work, too, with the \.\PhysicalDevice0 path. It may be a better way to go.
https://en.cppreference.com/w/cpp/filesystem/file_size
On Oct 10, 2021, at 8:20 PM, Simson L. Garfinkel @.***> wrote:
I'll be double checking! It would be great to get rid of the GetDiskGeometry() stuff.
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In fact, std::filesystem::file_size is what I moved to, and it really simplified a lot. But I need to test it with \\.\PhysicalDevice0
I think getting file size is still an issue for block devices.
terminate called after throwing an instance of 'std::filesystem::__cxx11::filesystem_error'
what(): filesystem error: cannot get file size: Operation not supported [/dev/sdb]
Also note that \\.\C: behaves differently from \\.\PhysicalDevice0 and typically you'll need to issue the correct WINAPI calls to get it reading the full volume.
