Editing 9P (protocol) (section)

{{Short description|A network protocol developed for the Plan 9 distributed operating system}}
{{Multiple issues|
{{Technical|date=February 2017}}
{{Primary sources|date=August 2015}}
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{{Infobox networking protocol
| title        = 9P
| logo         = 
| logo alt     = 
| image        = 
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| caption      = 
| is stack     = No
| abbreviation = 
| purpose      = Connecting components
| developer    = [[Bell Labs]]
| date         = {{Start date and age|1992}}
| based on     = 
| influenced   = 9P2000
| osilayer     = 
| ports        = 
| rfcs         = 
| hardware     = 
}}
{{IPstack}}
'''9P''' (or the '''Plan 9 Filesystem Protocol''' or '''Styx''') is a [[network protocol]] developed for the [[Plan 9 from Bell Labs]] [[distributed operating system]] as the means of connecting the components of a Plan 9 system. Files are key objects in Plan 9. They represent [[window (computing)|windows]], [[computer network|network]] connections, [[process (computing)|processes]], and almost anything else available in the operating system.

9P was revised for the 4th edition of Plan 9 under the name '''9P2000''', containing various improvements. Some of the improvements made are the removal of certain filename restrictions, the addition of a 'last modifier' metadata field for directories, and authentication files.<ref>{{Cite web|url=https://9p.io/plan9/about.html|title=Plan 9 from Bell Labs — Overview|website=9p.io}}</ref> The latest version of the [[Inferno operating system]] also uses 9P2000. The Inferno file protocol was originally called Styx, but technically it has always been a variant of 9P.

A server implementation of 9P for Unix, called u9fs,<ref>{{Cite web|url=https://www.netlib.org/research/|title=research: u9fs.tgz is the source code tarbal|website=www.netlib.org}}</ref><ref>{{Cite web|url=http://9p.io/magic/man2html/4/u9fs|title=Plan 9 /sys/man/4/u9fs|website=9p.io}}</ref> is included in the Plan 9 distribution. A 9P [[OS X]] client [[kernel extension]] is provided by Mac9P.<ref>{{Cite web|url=https://github.com/benavento/mac9p|title=9P for Mac|author=benavento|date=April 19, 2019|via=GitHub}}</ref> A kernel client driver implementing 9P with some extensions for [[Linux]] is part of the [[v9fs]] project. 9P and its derivatives have also found application in embedded environments, such as the Styx-on-a-Brick project for [[Lego_Mindstorms#RCX|Lego Mindstorms Bricks]].<ref>{{Cite web |url=http://doc.cat-v.org/inferno/4th_edition/styx-on-a-brick/ |title=Styx-on-a-Brick |website=Cat-V Doc }}</ref>