Editing Path (computing) (section)

==Universal Naming Convention==
{{Anchor|UNC}}
The Microsoft '''universal naming convention''' ('''UNC'''), a.k.a. '''uniform naming convention''', a.k.a. '''network path''', specifies a syntax to describe the location of a network resource, such as a shared file, directory, or printer. A UNC path has the general form:

 \\ComputerName\SharedFolder\Resource

Some Windows interfaces allow or require UNC syntax for [[WebDAV]] share access, rather than a URL. The UNC syntax is extended<ref>{{cite web |title=DavGetHTTPFromUNCPath function |department=WebDAV: Windows |website=[[Microsoft Docs]] |series=series |date=13 October 2021 |url=https://learn.microsoft.com/windows/win32/api/davclnt/nf-davclnt-davgethttpfromuncpath |access-date=2023-10-04}}</ref> with optional components to denote use of SSL and TCP/IP port number, a WebDAV URL of <code>http[s]://HostName[:Port]/SharedFolder/Resource</code> becomes

 \\HostName[@SSL][@Port]\SharedFolder\Resource

When viewed remotely, the "SharedFolder" may have a name different from what a program on the server sees when opening "\SharedFolder". Instead, the SharedFolder name consists of an arbitrary name assigned to the folder when defining its "sharing".

Some Windows interfaces also accept the "Long UNC":

 \\?\UNC\ComputerName\SharedFolder\Resource

Windows uses the following types of paths:

* local file system (LFS), such as <code>C:\File</code>
* universal naming convention (UNC), such as <code>\\Server\Volume\File</code> or /<code><internet resource name>[\Directory name]</code> (at least in Windows 7 and later)
* "long" device path such as <code>\\?\C:\File</code> or <code>\\?\UNC\Server\Volume\File</code>.<ref name="netpaths">{{cite web |title=File path formats on Windows systems |department=File and Stream I/O: .NET |website=[[Microsoft Docs]] |url=https://learn.microsoft.com/dotnet/standard/io/file-path-formats |access-date=2019-07-14}}</ref> This path points to the local file namespace and {{code|\\.\}} is a similar one that points to the local DOS device namespace. This format is also the "raw" or "uninterpreted" path, since it sends paths straight to the file system without converting {{mono|/}} to {{mono|\}} and interpreting names like {{mono|..}}.<ref name="w32paths" />
* [[Object Manager (Windows)|Windows NT object manager]] <code>\\??\</code>-prefixed paths (global DOS namespace).<ref>{{cite web |title=winapi - Is there a difference between \??\ and \\?\ paths? |website=Stack Overflow |url=https://stackoverflow.com/questions/25090101/is-there-a-difference-between-and-paths}}</ref><ref>{{cite web |title=Path prefixes \??\ and \\?\ |website=Stack Overflow |url=https://stackoverflow.com/a/46019856}}</ref>

In versions of Windows prior to Windows XP, only the APIs that accept "long" device paths could accept more than 260 characters.

The [[Windows shell|shell]] in [[Windows XP]] and [[Windows Vista]], [[explorer.exe]], allows path names up to 248 characters long.{{citation needed|date=February 2014}}

Since UNCs start with two backslashes, and the backslash is also used for string escaping and in [[regular expression]]s, this can result in extreme cases of [[leaning toothpick syndrome]]: an escaped string for a regular expression matching a UNC begins with 8 backslashes – <code>\\\\\\\\</code> – because the string and regular expression both require escaping. This can be simplified by using [[raw string]]s, as in C#'s <code>@"\\\\"</code> or Python's <code>r'\\\\'</code>, or regular expression literals, as in Perl's <code>qr{\\\\}</code>.