simple-unc 0.2.3

Simplify Windows UNC path for `fs::canonicalize`
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[![CI-badge]][CI]
[![crate-badge]][crate]
[![docs-badge]][docs]

[CI-badge]: https://github.com/kojiishi/simple-unc/actions/workflows/rust-ci.yml/badge.svg
[CI]: https://github.com/kojiishi/simple-unc/actions/workflows/rust-ci.yml
[crate-badge]: https://img.shields.io/crates/v/simple-unc.svg
[crate]: https://crates.io/crates/simple-unc
[docs-badge]: https://docs.rs/simple-unc/badge.svg
[docs]: https://docs.rs/simple-unc/

# SimpleUnc

On Windows,
[`fs::canonicalize`] returns a path prefixed by "`\\?\`".
such as:
```
\\?\UNC\server\share\dir
```
The "`\\?\`" prefix is called the [Win32 File Namespaces].
It has advantages such as long paths,
and is fine for most modern APIs,
but some programs can't handle them.
PowerShell and `cmd.exe` are examples of such programs.

The `SimpleUnc` simplifies network share UNC paths
so that these programs can handle.

| | `C:\dir` | `Z:\x` (network) |
| --- | --- | --- |
| [`fs::canonicalize`] | `\\?\C:\dir` | `\\?\UNC\server\share\x` |
| `SimpleUnc` | `C:\dir` | `\\server\share\x` |
| `SimpleUnc` with [`map_to_drive`] | `C:\dir` | `Z:\x` |

Since the simplification may not always be safe,
it does so if they are currently mapped to drives.

Let's say your PC has a network share on the `Z:` drive:
```
net use Z: \\server\share
```
If you run the following code on this PC:
```rust
let path = r"Z:\dir\file";
let canonicalized = fs::canonicalize(path)?;
println!("{}", canonicalized.display());
```
prints:
```
\\?\UNC\server\share\dir\file
```
Neither PowerShell nor `cmd.exe` can handle this path.

With the `SimpleUnc`:
```rust
let path = r"Z:\dir\file";
let simplified = SimpleUnc::default().canonicalize(path)?;
println!("{}", simplified.display());
```
prints:
```
\\server\share\dir\file
```
This path works fine for PowerShell and `cmd.exe`.

## Drive

If you prefer to use the network drive in the path:
```rust
let path = r"Z:\dir\file";
let unc = SimpleUnc { map_to_drive: true, ..Default::default() };
let simplified = unc.canonicalize(path)?;
println!("{}", simplified.display());
```
prints:
```
Z:\dir\file
```

## Dunce

The `SimpleUnc` calls the [`dunce`] crate
to normalize some other cases, such as:
```
\\?\C:\foo
```
to:
```
C:\foo
```
You can skip the [`dunce`] simplification if you prefer:
```rust
let unc = SimpleUnc { skip_dunce: true, ..Default::default() };
```

## Other Platforms

On other platforms,
the `SimpleUnc` returns without doing anything.

You can wrap the calls with `#[cfg(windows)]` if you prefer,
though it's not necessary to build and run.

[`dunce`]: https://crates.io/crates/dunce
[`fs::canonicalize`]: https://doc.rust-lang.org/std/fs/fn.canonicalize.html
[`map_to_drive`]: https://docs.rs/simple-unc/latest/simple_unc/struct.SimpleUnc.html#structfield.map_to_drive
[Win32 File Namespaces]: https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#win32-file-namespaces