FQA INDEX | FQA 7 - System Management | FQA 9 - Troubleshooting

FQA 8 - Using 9front

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i am form china

here is lots of people knows

 and documented is chinese

 the time comllexity is need you test youself

and you will find it

— wenwei peng

When applied consistently, simple conventions can combine to provide powerful results. In Plan 9, conventions are preferred to rules. This section explores the Plan 9 approach to actually using the computer.

8.1 - rc

The rc shell was written by Tom Duff for Research UNIX v10. It was later adopted as the shell for Plan 9. Some of its conventions are unusual compared with other command interpreters influenced by the Bourne shell. Although its syntax may seem strange at first, have patience; rc was designed this way on purpose. Once its (few, but powerful) features are internalized, rc simply gets out of the way.

Read: Rc - The Plan 9 Shell, rc(1)

8.1.1 - Prompts

Creating an rc function with the same name as your prompt allows you to easily double-click to select at the end of a previously typed line and then send it using the mouse button 2 menu (see the discussion of rio menus, below). This can be used to approximate a form of command history (see also the commands " and "", which print and execute the previous command, respectively).

Add something like this to your $home/profile:

fn term%{ $* }

In rc the ; character forces the end of a line and is treated as a noop when it appears alone, so it is also possible to create a simple prompt that would require no special prompt function in order for the prompt to be effectively ignored when selecting and sending:

prompt='; '

Obviously, the prompt can be named however the user sees fit.

8.1.2 - /env

Note: Contents of the /env directory are provided by the kernel and represent a separate accounting of the shell’s environment; rc reads /env only on startup, and flushes/writes /env only before executing programs.

8.2 - rio

rio is the Plan 9 window system. More accurately, rio multiplexes input devices with and serves a file interface to a series of rectangles, inside the boundaries of which are drawn an arbitrary arrangement of pixels. Controlling the rectangles is more straightforward, and at the same time more flexible, than what is commonly expected from most "window managers."

Read: rio(1), rio(4)

To effectively use rio, you need a three button mouse. If you only have a two button mouse you can emulate the middle button by holding down the shift key whilst pressing the right button.

Note: Button 1, 2, and 3 are used to refer to the left, middle, and right buttons respectively.

8.2.1 - The Pop-up Menu

Pressing and holding down mouse button 3 on the gray desktop or on a shell window will give you a menu with the following options:

Pressing and holding down mouse button 2 on a shell window results in a menu with the following options:

Select an item by releasing the button over the menu item. Rio uses the same button that started an action throughout that operation. If you press another button during the action the operation is aborted and any intermediate changes are reversed.

Each menu acts as a action verb selector which then requires an object (i.e. window) to be picked to indicate which window the verb is to act on. A further mouse action may then be required.

8.2.2 - Window control

Clicking on a window brings it to the front.

You can directly change the shape of a window by clicking and dragging on the edge or corner of the window border. Mouse button 1 or 2 will allow you to drag the edge or corner to a new size, and mouse button 3 will allow you to move the window.

The mouse button 3 menu contains a list of all windows that are corrently obstructed by other windows. Selecting a label tops the window.

The pop-up menu remembers the last command chosen, so as a shortcut you can just press and release button 3 without moving the mouse between pressing and releasing to select the previous command again.

In addition, rio serves a variety of files for reading, writing, and controlling windows. Some of them are virtual versions of system files for dealing with the display, keyboard, and mouse; others control operations of the window system itself. These files, as well as the window(1) command, allow for controlling windows programmatically by reading and writing text strings. Thus simplifying the automated opening and placement of various windows with user scripts.

Read: rio(4)

8.2.3 - Text in rio windows

Text in a rio window may be freely manipulated, edited, altered, deleted and/or acted upon using either mouse chords or the options from the mouse button menus. (For an example, see the discussion of the use of rc prompts, above.)

The special file /dev/text (for the current window), or /dev/wsys/n/text (for window n) contains all text that has already appeared in the window. The contents of this file may serve as a primitive form of command history (and may be acted upon using standard command line tools), but are lost when the window is closed.

Seriously, read: rio(4)

8.2.4 - Scrolling

By default, a rio window will fill up with text and then block, obviating the need for a separate pager program (though the p(1) pager program still ships with the system).

Endless scrolling may be enabled by selecting scroll from the mouse button 2 menu.

The up or down arrow keys and pgup or pgdwn keys may be used to scroll up or down in consistently measured increments.

Holding down the shift key and pressing the up or down arrow key will scroll a single line in the respective direction.

9front’s rio supports mousewheel scrolling. The heuristic employed is roughly the same as that of clicking in the scrollbar on the left of the window: when the mouse pointer is near the top of the window the scrolling increment is small, while as the mouse pointer approaches the bottom of the window the scrolling increment grows progressively larger. Presently this behavior is limited to rio, sam, and mothra but may later be extended to other programs.

Note: While the behavior of the arrow and page keys is fairly consistent between programs, mousewheel scrolling is not. So far, shift + up or down is only supported in rio windows.

8.2.5 - Mouse Chording

Almost anywhere — sam(1), acme(1), window(1) — you can use the following mouse chords:

mb1 — Select text.

mb1 double click — Select word under cursor, or at the end/start of a line, select the whole line.

After selecting with mb1 and while still holding mb1 down (these chords also work with text selected by double-clicking, the double-click expansion happens when the second click starts, not when it ends):

mb2 — Cut text.

mb3 — Paste text (can be reverted by clicking mb2 immediately afterwards).

To snarf (copy), click mb2 immediately followed by mb3.

8.2.6 - Keyboard Shortcuts

Almost anywhere — sam(1), acme(1), window(1) — you can use the following shortcuts:

Ctrl-u — Delete from cursor to start of line.

Ctrl-w — Delete word before the cursor.

Ctrl-h — Delete character before the cursor.

Ctrl-a — Move cursor to start of the line.

Ctrl-e — Move cursor to end of the line.

Ctrl-b — Move cursor to the position immediately after the prompt. (rio only)

Read: UNIX Keyboard Bindings

In a rio(1) window, scroll up or down one line by holding shift and pressing the up or down arrow.

8.2.7 - Color scheme

rio looks like this:

rio’s color scheme may be modified by editing the .c configuration files and re-compiling:

Note: Someone will mock you for doing this.

See: http://plan9.stanleylieber.com/rio

Rob Pike, rio’s author, was all like:

Rob Pike, 2003

Rob Pike, 2008

See: edwardtufte.com

8.2.8 - Why is rio like this?

Window systems should be transparent. That’s the argument put forward in the famous paper by rio’s author, Rob Pike.

Beyond this, Rob offered an explanantion (in response to a question on the 9fans mailing list) of some of the choices made in the design of and rio:

Rob Pike, 2001

8.2.9 - tips - Taking a screenshot

To capture the entire screen:

topng </dev/screen >screen.png

To capture only the current window:

topng </dev/window >window.png

It is also possible to capture other windows:

topng </dev/wsys/n/window >window.png

where n is the number of the window being captured.

Read: rio(4) - Prevent console messages from overwriting the screen

To capture console messages in a rio window, open a new window and:

cat /dev/kprint

8.3 Text Editors

8.3.1 - sam

The text editor sam was created by Rob Pike for Research UNIX V9 (circa 1986), and later included with Plan 9.

See: http://sam.cat-v.org


The Text Editor sam — The original paper by Rob Pike.

A Tutorial for the Sam Command Language — Documents the editing language.

sam quick reference card

sam(1) man page

Dan Flavin, Document for Untitled (to the “innovator” of Wheeling Peachblow), 1968 - Scrolling

9front’s slightly modified version of sam supports mousewheel scrolling in the same manner as rio.

Read: FQA 8.2.4 - Scrolling - Mouse Chording

9front sam supports the same mouse chording as rio.

Read: FQA 8.2.5 - Mouse Chording - Why does sam have a separate snarf buffer from rio?

The program’s author, Rob Pike, says:

Rob Pike, 2003 - Keyboard Shortcuts

Esc — Cut (and consequently, snarf) the selected text.

Ctrl-b — Switch focus to the edit window.

8.3.2 - acme

There is also an alternative user interface, acme(4), that some people use as their editor.

— Geoff Collyer

Handmade cyclogram by Russian cosmonaut, Georgi Grechko.

8.4 - Internet

Sending and receiving bits via alien protocols.

8.4.1 - Mail

Read: mail(1), FQA 7.7 - Mail server configuration and maintenance - upasfs

From upasfs(4):

Read: upasfs(4), pop3(8), faces(1) - Reading gmail via IMAP

upas/fs -f /imaps/imap.gmail.com/your.username@gmail.com

The first time this command is run, you should see an error that looks something like this:

upas/fs imap: server certificate 22471E10D5C1E41768048EF5567B27F532F33

    not recognized

upas/fs: opening mailbox: bad server certificate

To add this certificate to your system, type:

echo 'x509 sha1=22471E10D5C1E41768048EF5567B27F532F33' \


Once upas/fs is running, you can open as many additional gmail mailboxes (labels) as you wish:

echo open /imaps/imap.gmail.com/your.username@gmail.com/yourlabel \

    yourlabel >/mail/fs/ctl

Note: upas/fs reads the entire mailbox into RAM, which means it may fail to load mailboxes that exceed the available system memory. This problem has been addressed in Erik Quanstrom’s nupas, which reads the mailbox into an index file, then performs new operations on the index where possible. - nedmail

nedmail is a command line mail client similar to the classic mail client shipped with Research UNIX.

Read: nedmail(1) - nupas

Read: Scaling Upas, by Erik Quanstrom

Download, pre-patched for 9front: nupas.tgz

Note: Installing nupas replaces the system’s default upas. Read the included README.9front and mkfile before attempting to install.

8.4.2 - NNTP

Read: newt(1), nntpfs(4)

8.4.3 - IRC - ircrc

ircrc is an IRC client implemented in rc. It is included with 9front.

Read: ircrc(1) - irc7

A persistent IRC client was written in the c programming language by Andrey Mirtchovski. It has been modified slightly by 9front users (mainly, adding an -e flag to the ircsrv program that implements SSL connections).

Download it here:

8.4.4 - FTP

Read: ftpfs(4)

8.4.5 - HTTP - mothra

mothra is a trivial web browser written in 1995 by Tom Duff. It ignores Javascript, CSS and many HTML tags. It was dropped from Plan 9 after the 2nd Edition, but has been picked up and (somewhat) refined for 9front. mothra now uses webfs, and no longer supports non-HTTP protocols.

Read: mothra(1), webfs(4) - abaco

no. - hget

hget is a command line HTTP client (similar to programs such as curl or wget) that started out as a c program in Plan 9 from Bell Labs, but was re-implemented in rc for 9front. hget now uses webfs and no longer supports non-HTTP protocols.

Read: hget(1), webfs(4) - charon

The Inferno operating system can be run hosted on Plan 9, and includes a GUI web browser called charon, which implements ECMASCRIPT 1.0 as well as additional HTML attributes.

Note: charon is ancient and is not really a sufficient replacement for 9front’s web browsers. The rudimentary javascript support can be useful for some simple tasks. - i

There exists an unfinished/buggy port of charon from Inferno’s limbo programming language to Plan 9 c.

Source is available here:

8.4.6 - SSH

Several SSH clients exist for Plan 9, none of which are perfect. - ssh

9front ships with the original Plan 9 native SSH1 client from Bell Labs.

Read: ssh(1) - ssh2

Programmers at Coraid created a Plan 9 native SSH2 client that was picked up (and completely rewritten) by Bell Labs. It is currently not included with 9front.

Download the Bell Labs version (pre-patched for 9front) here: ssh2.tgz

Note: There are bugs and expected features are missing. Consult the source. - scpu

Two 9front users (taruti and mischief) worked on an SSH2 client written in the Go programming language. It has been extended to work with Plan 9 factotum(4), but still does not fully honor complex Plan 9 dial(2) strings.

Download it here: https://bitbucket.org/mischief/scpu. - Public Key Authentication

The scpu command can be configured to use public key authentication:

auth/rsagen -t ’service=ssh’ >$home/lib/ssh/key

auth/rsa2ssh -2 $home/lib/ssh/key >$home/lib/ssh/key.pub

cat $home/lib/ssh/key >/mnt/factotum/ctl    # must be present before running scpu

Then add the contents of $home/lib/ssh/key.pub to $HOME/.ssh/authorized_keys on the remote host.

Note: This same key may be used for multiple hosts. - OpenSSH

Plan 9 user fgb ported OpenSSH 4.7p1, OpenSSL 0.9.8g 19 Oct 2007 to Plan 9. It is available in his contrib directory (on the Bell Labs server), or a 386 binary is available here (to install, unpack it over /): openssh.tgz. - sftpfs

An implementation of sftpfs was created for Plan 9 that can work with either the native SSH clients or fgb’s OpenSSH port.

Download it here:
sftpfs.tgz - Mounting a remote u9fs share over SSH

The u9fs program runs on UNIX and serves an unencrypted 9P(2) share. It is possible to mount such a share over SSH.

With ssh2:

srv -s 5 -e 'ssh2 -l sl wm ''/usr/local/bin/u9fs \

    -u sl -na none''' wm /n/wm

With scpu:

srv -s 5 -e 'scpu -u sl -h wm -c \

    ''/usr/local/bin/u9fs -u sl -na none''' wm /n/wm

In both cases, an SSH connection is opened to remote UNIX host wm, logged in with user sl and mounted on Plan 9 under /n/wm.

Read: u9fs(4), srv(4)

8.4.7 - secstore

Typing in lots of passwords over and over again is annoying.

Secstore authenticates to a secure-store server using a password and optionally a hardware token, then saves or retrieves a file. This is intended to be a credentials store (public/private keypairs, passwords, and other secrets) for a factotum.

Read: FQA 7.4.3 - secstored for information on setting up the secstore server, and: FQA - Adding users to secstore to add users.

Once a user has been added to secstored, the user may add to the file read by factotum at startup. To do so, open a new window and type

% ramfs -p; cd /tmp

% auth/secstore -g factotum

secstore password: [user’s secstore password]

% echo 'key proto=apop dom=x.com user=ehg !password=hi' >> factotum

% auth/secstore -p factotum

secstore password: [user’s secstore password]

% read -m factotum > /mnt/factotum/ctl

and delete the window. The first line creates an ephemeral memory-resident workspace, invisible to others and automatically removed when the window is deleted. The next three commands fetch the persistent copy of the secrets, append a new secret, and save the updated file back to secstore. The final command loads the new secret into the running factotum.

The ipso command packages this sequence into a convenient script to simplify editing of files stored on a secure store. It copies the named files into a local ramfs and invokes editor on them. When the editor exits, ipso prompts the user to confirm copying modifed or newly created files back to secstore. If no file is mentioned, ipso grabs all the user’s files from secstore for editing.

By default, ipso will edit the secstore files and, if one of them is named factotum, flush current keys from factotum and load the new ones from the file.

Read: secstore(1), secstore(8)

8.4.8 - drawterm

drawterm is a program that users of non-Plan 9 systems can use to establish graphical cpu connections with Plan 9 cpu servers. Just as a real Plan 9 terminal does, drawterm serves its local name space as well as some devices (the keyboard, mouse, and screen) to a remote cpu server, which mounts this name space on /mnt/term and starts a shell. Typically, either explicitly or via the profile, one uses the shell to start rio. The original version is effectively abandoned, but is available here: http://swtch.com/drawterm

There also exists a fork of Russ Cox’s drawterm that incorporates features from 9front, most importantly DP9IK authentication support (see authsrv(6)) and the TLS based rcpu(1) protocol: http://drawterm.9front.org.

Note: The fork is the preferred version of drawterm for use with 9front because the old auth protocol is considered deprecated and the old CPU listeners are now disabled by default.

8.5 - Audio

Read: audio(1), audio(3)

8.6 - External Media

8.6.1 - Mount an ISO9660 CD-ROM

mount <{9660srv -s} /n/iso /dev/sdD1/data # cd-rom drive


mount <{9660srv -s} /n/iso /path/to/9front.iso

Read: dossrv(4)

8.6.2 - Burn a CD-ROM


cp 9front.iso /mnt/cd/wd

rm /mnt/cd/wd

Read: cdfs(4)

8.6.3 - Mount a FAT formatted USB device

FAT formatted USB devices are automatically mounted under the /shr directory.

Note: Devices must be FAT or FAT32 formatted; exFAT is not supported.

8.7 - Emulation

8.7.1 - Linux Emulation

linuxemu is a program that can execute Linux/i386 ELF binaries on Plan 9. Semi-modern web browsers and other Linux programs may be run using linuxemu (if necessary, in conjunction with the equis X11 server).

Download it here: linuxemu3.tgz

The equis X11 server is available from 9front.org/exra/, or contrib(1)).

Note: linuxemu can only be run on a Plan 9 system booted with a 386 kernel and binaries.


To run linuxemu, you need a Linux root file system packed into a tarball:



The mroot-linuxemu.tbz version contains no symlinks and can be extracted with plain Plan 9 tools bunzip and tar.

The mroot.tgz version contains the same Debian Sarge base as mroot-linuxemu.tbz, but with several additional packages pre-installed:

and more.

You can create your own mroot with debootstrap on Debian Linux, or help write an installer that unpacks and installs an alternative distribution on Plan 9... In any case, linuxemu is not hardwired to any Linux distribution!


Use the provided linux script to chroot into your Linux mroot. The linux script is neccesary because for Linux programs to run, shared libraries from your mroot have to appear in its /lib and /usr/lib directories, while configuration files are expected to be in /etc. The script will build a private namespace and then bind the Linux mroot over the Plan 9 root. The original Plan 9 namespace is mounted within linuxemu under /9.

Assuming mroot is located in the current directory, start linuxemu like this:

linux -r ./mroot /bin/bash -i

If the -r option is omitted, the Linux mroot defaults to /sys/lib/linux on the Plan 9 machine.

In the Linux mroot, /etc/resolv.conf should be changed to match your network nameserver. In addition, /etc/apt/sources.list should be updated to a working Debian mirror. Sarge packages can still be accessed at:

deb http://archive.debian.org/debian-archive/debian sarge main


Linux X11 programs may be used in conjunction with the equis X11 server. For example, to run the Opera web browser under your Linux mroot, start equis in a rio window, start linuxemu in another rio window and then from within linuxemu:

dwm & # X11 window manager

opera & # web browser

Opera should (eventually) appear in the equis window. A window manager (this example uses dwm) is recommended so that X11 programs interact with window resources properly.


If linuxemu crashes, use acid to figure out whats going on:

mk acid

acid -l linuxemu.acid <pid>

Then you can issue the following commands:


dump a (userspace) stacktrace for the current thread:

umem(Current())     dump the memory mappings

ufds(Current())     dump the filedescriptor table

utrace(Current())   dump the internal tracebuffer

            (enabled by -d option)

Use xasm() and xcasm() for disassembly for Linux code.

Read: acid(1)

You can also enable full trace logging:

linux -r ./mroot -dd /bin/bash -i >[2]/tmp/linuxemu.log

This slows linuxemu down considerably. In case of race conditions, it often happens that the bug disapears when doing full trace logging!

8.7.2 - Nintendo

Emulators for several Nintendo video game consoles ship with the system:

Read: nintendo(1)

8.7.3 - Sega

An emulator for the Sega Megadrive/Genesis video game console ships with the system:

Read: sega(1)

8.7.4 - Commodore

An emulator for the Commodore 64 home computer ships with the system:

Read: commodore(1)

8.8 - Additional Software

8.8.1 - 9front sources server

Additional 9front software is available from a 9P share that is accessible from any Plan 9 system:

9fs 9front

The following files and directories will then be available under /n/:

8.8.2 - 9front contrib

Some 9front users maintain a contrib directory on an official 9front 9P share (similar to the contrib arrangement provided by Bell Labs) that is accessible from any Plan 9 system:

9fs 9front

User directories will then be available under /n/contrib/.

These directories are also accessible via HTTP: http://contrib.9front.org

8.8.3 - Other public 9p servers

A list of active public 9p servers is maintained here: http://www.9paste.net/qrstuv/9pindex

8.9 - Bootstrapping architectures not included on the ISO

8.9.1 - amd64

To setup the amd64 port, install the 386 port from the ISO, then cross compile and install the amd64 binaries and kernel.

Read: FQA - Cross compiling, FQA 7.2.5 - How do I install a new kernel?

8.9.2 - Raspberry Pi

The most convenient way to use an rpi is to cross compile and install the arm binaries and the bcm kernel on the network file server, and then tcp boot the rpi.

Read: FQA - Cross compiling, FQA 6.7.1 - How do I tcp boot?

Outdated and possibly confusing instructions for installing directly onto the rpi’s sd card are detailed in Appendix J - Junk

8.10 - ACPI

Plan9front currently has partial ACPI support for PCI interrupt routing and system shutdown.

8.10.1 - Enabling ACPI

ACPI is enabled with the presence of *acpi= boot parameter.

This will create the /dev/acpitbls file that can be used to read the systems acpi tables. Specifying *acpi=0 will make acpi tables accessible thru the file but not use it in the kernel.

8.12 - Revision Control

8.12.1 - cvs

OpenCVS was ported to Plan 9.

Download it here:

An implementation of a cvs file server, called cvsfs, was also created for Plan 9.

Download it here: cvsfs.tgz

8.12.2 - git

More than one person has claimed to have ported git to Plan 9, but no code has ever been made public. Please stop telling unsuspecting newbs that git is available for Plan 9.

In the meantime, someone wrote a shell script wrapper that attempts to replicate some basic git actions by downloading a zip file from the repository and performing operations on it.

Download it here:

8.12.3 - Mercurial

9front ships with Mercurial.

Read: FQA - hgrc

See also: hgfs(4)

8.12.4 - svn


FQA INDEX | FQA 7 - System Management | FQA 9 - Troubleshooting