For the below code:

std::error_code ec;
auto long_path = std::filesystem::canonical("W:\\31\\arawat.fielsystem_default_check\\matlab\\check_std\\check_std\\").string();

I am getting the value of long_path as:

"\\\\bgl-zp31-cifs\\vmgr\\sbs31\\arawat.fielsystem_default_check\\matlab\\check_std\\check_std"

std::filesystem::canonical() is converting the path to a network UNC path. Is there any way to prevent it, or to get the original drive letter path back from a network path?

I have tried using Windows APIs like WNetGetUniversalName(), etc.

For the below code:

std::error_code ec;
auto long_path = std::filesystem::canonical("W:\\31\\arawat.fielsystem_default_check\\matlab\\check_std\\check_std\\").string();

I am getting the value of long_path as:

"\\\\bgl-zp31-cifs\\vmgr\\sbs31\\arawat.fielsystem_default_check\\matlab\\check_std\\check_std"

std::filesystem::canonical() is converting the path to a network UNC path. Is there any way to prevent it, or to get the original drive letter path back from a network path?

I have tried using Windows APIs like WNetGetUniversalName(), etc.

• c++
• windows
• winapi
• std-filesystem

Share Improve this question Follow edited Mar 10 at 21:51 Remy Lebeau 601k3636 gold badges507507 silver badges851851 bronze badges asked Mar 10 at 12:53 Atul RawatAtul Rawat 1911 silver badge11 bronze badge 4

• 1 Perhaps because the W drive is a network drive? And why is this a problem? – Some programmer dude Commented Mar 10 at 12:55
• 8 That is literally what "canonical path" means. If you were to mount (some subpath of) that network share to a different drive, you would get back the canonical URL again. This is a feature, not a bug. – Botje Commented Mar 10 at 13:59
• 4 I don't think that there's an inverse function. You could have W: and X: mapped to the same network location (or a subdirectory thereof). Then the inverse function would need to return 2 results. – Thomas Weller Commented Mar 10 at 14:18
• The function is performing properly and doing what it's meant to do. Maybe it would help if you explained what result you are expecting in the above example? – Jonathan Potter Commented Mar 12 at 17:32

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 2

is there any way to prevent it ...

Yes, just use std::filesystem::path:

auto long_path = std::filesystem::path("...");

If the path contains relative elements and you'd like to resolve them into a full path, use std::filesystem::absolute:

auto long_path = std::filesystem::absolute("...");

Example:

#include <iostream>
#include <filesystem>

int main()
{
    auto long_path = std::filesystem::path(R"aw(N:\proj\stackoverflow\..)aw");
    std::cout << long_path << '\n';
    std::cout << std::filesystem::absolute(long_path) << '\n';
    std::cout << std::filesystem::canonical(long_path) << '\n';
}

Possible output:

"N:\\proj\\stackoverflow\\.."
"N:\\proj"
"\\\\192.168.1.4\\ted\\proj"