Documentation for rc is here

There's a plethora of useful things here:

• rcrc - start-up script adding a nice prompt, pushd,popd,activate,deactivate activate and deactivate maintain a stack of VIRTUAL_ENV variables like pushd and popd. Internally, all the implementations use rc lists (path_history and venv_history, respectively).

  cp rcrc $HOME/.rcrc

• profile.rc - some other helpful functions (lmod support)

• vim/ - vim plugins to recognize rc scripts

  mkdir -p $HOME/.vim/ftdetect cp vim/ftdetect/rcshell.vim $HOME/.vim/ftdetect mkdir -p $HOME/.vim/syntax cp vim/syntax/rcshell.vim $HOME/.vim/syntax

• bin/* - various useful scripts

  mkdir $HOME/bin path = ($path $HOME/bin) cp bin/* $HOME/bin/

If you enjoy the rc shell, you might also like to try other 9P applications available inside plan9port.

The mk build system is especially notable. Also, the factotum+secstore+secstored triad makes a full featured password manager that even has ssh integration.

The push toward reliable containerization technology has made modern Linux able to provide many of the key features of Plan9.

Note especially the following projects:

• https://github.com/containers/fuse-overlayfs

  Which makes it possible to mount a user-defined filesystem that binds multiple paths together. Using this, it's possible to do things like merge /usr onto $HOME/local -- so that $HOME/local acts like /usr, but has user-additions.

• https://github.com/containers/bubblewrap

  This is a user-space sandbox that replaces / with a set of user-defined directories.

  For more context on what bubblewrap is doing, see Michael Kerrisk's LWN tutorial.

• https://pkg.go.dev/github.com/frobnitzem/go-p9p

  This provides a high-level way to create your own sever application that responds to 9P2000 file operations.

• https://github.com/mischief/9pfs

  This is one of the best fuse filesystems for mounting 9P2000 filesystems. It seems to have fallen out of maintainence - likely because FUSE has put on several version evolutions since 9pfs was written. Also, I remember fixing a bug in its directory caching mechanism somewhere, and need to upload that back to github.

• additional libraries

1. install plan9port

   then copy plan9port/bin/9 to $home/bin/9 and set its PLAN9 accordingly.

9 factotum

Interact with 9p following factotum protocol.

% 9 9p ls factotum/
confirm
conv
ctl
log
needkey
proto
rpc

Add a key

% 9 9p write factotum/ctl
> key role=client proto=pass service=ssh user=99r dom=ornl !password=12345

Lookup a key

% 9 9p rdwr factotum/rpc
> start proto=pass role=client service=ssh user=99r
< ok / error string
> read
< ok 99r 12345

Note this will return any matching key. If no key is present, it may return with, e.g.

needkey user? !password? proto=pass role=client service=ssh dom=olcf

Sending another read will return either error or ok <data> (if the needkey process supplied the needed key), as in the following,

start proto=pass role=client service=ssh dom=olcf
ok
read
needkey user? !password? proto=pass role=client service=ssh dom=olcf
read
error pass client nascent: no key found
start proto=pass role=client service=ssh dom=olcf
ok
read
needkey user? !password? proto=pass role=client service=ssh dom=olcf
read
ok a ok

Serve a key request:

% 9 9p rdwr factotum/needkey
< needkey tag=tagno <template>
[add key via factotum/ctl]
> tag=tagno

% pinentry -g
OK Pleased to meet you
SETPROMPT Password required for code.ornl.gov
OK
GETPIN
D nope
OK
GETPIN
ERR 83886179 Operation cancelled <Pinentry>

Providing "nope" on the first entry and pressing "Cancel" on the second.