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Subject: Re: [PHP-DEV] Directory separators on Windows
From: php@fleshgrinder.com (Fleshgrinder)

On 3/30/2017 3:25 PM, Rasmus Schultz wrote:
> Thoughts?
> 

Windows and paths is a complicated and lengthy story.

TL;DR all versions of Windows are able to deal with slashes, and we
could easily use slashes everywhere all the time.

# History
The story why Windows is using the backslash might be of interest, read:

http://blogs.msdn.com/b/larryosterman/archive/2005/06/24/432386.aspx

This also explains that Windows IS supporting forward slashes since at
least the 1990s. However, there are programs that have significant
problems with it, but usually those are old or otherwise shitty programs.

There are various ways paths can be represented in Windows, the so
called path variants. There are 7 in total:

1. Root
2. Disk
3. UNC
4. Device Namespace
5. Verbatim Disk
6. Verbatim UNC
7. Verbatim Device Namespace

## Root
This works just line on Unix an can be either `\` or `/`. It always
refers to the root directory of the current drive.

### Home
PowerShell also supports the home short-hand `~` like Unix systems,
however, `cmd.exe` does not.

## Disk
This is the one we all know. The drive letter comes first, followed by a
colon `:`, and then continues with the actual path.

`C:\Folder\Resource`
`C:/Folder/Resource`

## UNC
Is short for **Universal Naming Convention** or **Uniform Naming
Convention** allows one to refer to network paths or server shares.

`\\ComputerName\SharedFolder\Resource`
`//ComputerName/SharedFolder/Resource`

It also has an extended form for web resource:

`\\CompuserName[@SSL][@Port]\SharedFolder\Resource`

## Device Namespace
This allows one to directly address special devices, or again the disks
themselves.

`\\.\Device\Resource`
`//./Device/Resource`

## Verbatim *
The verbatim paths work exactly the same way as the respective normal
counterpart, the difference is that the slash to backslash conversion
does NOT happen auto-magically:

`\\?\C:\Folder\Resource`
`\\?\Server\Share`
`\\?\UNC\Server\Share`

https://en.wikipedia.org/wiki/Path_(computing)

I highly recommend you to have a look at Rust's path implementation, as
it takes care of all these things in a very intelligent manner. It is
also capable of dealing with all variants of paths in Windows, unlike
PHP which only supports a few:

https://doc.rust-lang.org/std/path/index.html

-- 
Richard "Fleshgrinder" Fussenegger