tshorter - plan9port - [fork] Plan 9 from user space
(HTM) git clone git://src.adamsgaard.dk/plan9port
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(DIR) commit e8b6ce11da23c3915fe0f71bfdec41d3564250e4
(DIR) parent adbb83845c5d3cb02343d7613cfb8385aa909909
(HTM) Author: rsc <devnull@localhost>
Date: Tue, 18 Jan 2005 05:42:48 +0000
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M NOTES | 253 ++-----------------------------
1 file changed, 11 insertions(+), 242 deletions(-)
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(DIR) diff --git a/NOTES b/NOTES
t@@ -1,258 +1,27 @@
-This is a port of some Plan 9 libraries and programs to Unix.
+This is a port of many Plan 9 libraries and programs to Unix.
-* Obtaining the source
+See http://swtch.com/plan9port for documentation.
+(Documentation is also in this tree, but you need to run
+a successful install first. After that, "9 man 1 intro".)
-Tarballs will be posted nightly (but only when there are updates!) at
-
- http://swtch.com/plan9port
-
-/usr/local/plan9 is the suggested location to keep the software.
-All the paths in the tarball begin with plan9/, so it's okay to unpack it
-directly in /usr/local.
-
-You can use CVS to obtain the very latest version and stay up-to-date.
-See below.
-
-* Building
-
-First, you need to extract the tarball or check out the CVS tree
-(see below for CVS). You should be able to install the tree anywhere
--- tools check the environment variable $PLAN9 for the root of the
-tree. Most of them assume /usr/local/plan9 if $PLAN9 is not set.
-
-To build and install, cd into the plan9/ directory and run "./INSTALL".
-This will first build "mk" and then use mk to build the rest of the
-system, installing libraries in plan9/lib/ and binaries in plan9/bin/.
-There are a few shell scripts already included in bin -- B, E,
-and samsave. Arguably these directories should be broken up by
-architecture so that
-
-During the initial build of mk, you will likely see a message like
-
- Assembler messages:
- Error: can't open getcallerpc-386.s for reading
- getcallerpc-386.s: No error
-
-This is not a problem. The script tries to build getcallerpc
-from assembly and then C. As long as one of them succeeds, great.
-
-There are various directories that are not built by default.
-They are listed in the BUGGERED definitions in src/mkfile and src/cmd/mkfile.
-These aren't built because they're not quite ready for prime time.
-Either they don't actually build or they haven't been very well tested.
-
-As of this writing, factotum is buggered because it's not done yet,
-and Venti and vac are buggered because they've hardly been tested
-and are in a state of flux (they were both quite rewritten for the port).
-
-
-* Writing programs
-
-The bin/ directory contains shell scripts 9a, 9c, 9l, and 9ar that mimic
-the Plan 9 tools pretty well, except in the object names: "9c x.c" produces
-x.o not x.9, and "9l x.o" produces "a.out" not "9.out" or "o.out".
-
-Mkfiles look substantially the same as in Plan 9, with slightly different
-names for the included rules. The most significant
-difference is that, since there is no autolinker, the Plan 9 libraries
-needed must be named explicitly. The variable SHORTLIBS can
-be used to list them without giving paths, e.g.:
-
- SHORTLIBS=thread bio 9
-
-The default is "SHORTLIBS=9". (Libc is known as lib9; libregexp is
-known as libregexp9; the rest of the libraries retain their usual names.)
-
-Various function names (like open, accept, dup, malloc) are #defined in
-order to provide routines that mimic the Plan 9 interface better
-(for example, open handles the OCEXEC flag). Lib9.h contains these
-definitions. Function "foo" is #defined to "p9foo". These definitions
-can cause problems in the rare case that other Unix headers are needed
-as well. To avoid this, #define NOPLAN9DEFINES before including lib9.h,
-and then add the p9 prefix yourself for the renamed functions you wish to use.
-
-* 9P servers and "name spaces"
-
-A few Plan 9 programs, notably the plumber and acme, are heavily
-dependent on the use of 9P to interact with other programs. Rather
-than rewrite them, they have been left alone. Via the helper program 9pserve,
-they post a Unix domain socket with a well-known name (for example,
-"acme" or "plumb") in the directory /tmp/ns.$USER.$DISPLAY.
-Clients connect to that socket and interact via 9P. 9pserve takes
-care of muxing the various clients of that socket onto a single 9P
-conversation with the actual server, just like the kernel does on Plan 9.
-
-The choice of "namespace" directory is meant to provide a different
-name space for each X11 session a user has. The environment variable
-$NAMESPACE overrides this. The command "namespace" prints the
-current name space directory.
-
-In order to run normal Unix commands with their input or output
-connected to a 9P server, there is a new 9P request "openfd" whose
-response contains a real Unix file descriptor. 9pserve handles
-this request by sending a normal open to the real 9P server and
-sending back one side of a pipe. Then 9pserver forks a thread to
-ferry bytes back and forth between its end of the pipe and the 9P
-conversation. This works reasonably well, but has the drawback
-that reads are no longer "demand-driven" (the ferry thread issues
-the reads and fills the pipe regardless of whether the other end
-of the pipe is being read) and writes cannot return errors (writes
-to the pipe by the application will always succeed even though the
-write in the ferry thread might actually draw an interesting error).
-This doesn't cause too many problems in practice, but is worth
-keeping in mind.
-
-The command "9p" interacts with a given server to read or write
-a particular file. Run "9p" for a usage message.
-
-* Plumbing
-
-There is a plumber. It expects to find a plumbing rule file in
-$HOME/lib/plumbing. $PLAN9/plumb/initial.plumbing is a
-good start.
-
-Sam and acme interact with the plumber as they do on Plan 9.
-(If there is no plumber, sam falls back to a named pipe
-as it always has on Unix.) Unlike on Plan 9, there is a "web"
-command whose purpose is to load files or URLs in a running
-web browser. Right now, only Mozilla Firebird and Opera are
-supported, but it should be easy to add others to the script.
-The plumbing rules in $PLAN9/plumb/basic know to run "web"
-to handle URLs.
-
-Because sam and acme read from the plumber using file descriptors
-(and therefore the openfd hack described above), if the editor exits,
-this fact is not noted until the ferry thread tries to write the next
-plumbing message to the pipe. At this point the ferry thread closes
-the corresponding plumber fid, but the plumber thinks the message
-has been sent -- the message is lost. The message did serve a purpose --
-now the plumber knows there are no readers of the "edit" channel,
-so when it gets the next message it will start a new editor.
-This situation doesn't happen often, but it is worth keeping in mind.
-
-Both acme and sam try to raise themselves when they get plumbing
-messages.
-
-* Acme
-
-Acme works.
-
-Programs executed with the middle button interact with acme by the
-"openfd" trick described above. In a plain execution (as opposed
-to >prog or |prog), because of the delay introduced by the pipes,
-there is no guarantee that the command output will finish being
-displayed before the exit status notice is displayed. This can be
-annoying.
-
-There is a "win" shell. Of course, since we're on Unix, win can't
-tell when programs are reading from the tty, so proper input point
-management is right out the window.
-
-* Rio, 9term
-
-There is a 9wm-derived window manager called rio.
-Along with the terminal 9term, the emulation feels
-quite like Plan 9.
-
-* Window Placement
-
-All the graphical Plan 9 programs accept a new -W option
-that can be used to specify window size. The syntax is
-
-acme -W spec
-
-where spec can be WIDTHxHEIGHT, WIDTHxHEIGHT@XMIN,YMIN
-'XMIN YMIN XMAX YMAX' or XMIN,YMIN,XMAX,YMAX.
-
-* Mouse scrolling
-
-The libraries pass along buttons 4 and 5, so if you have a
-scroll mouse and have X configured to send the up/down
-events as buttons 4 and 5, acme and 9term will scroll in
-response.
-
-You will likely need to change your X config to enable this.
-In my XF86Config-4 I have
-
-Section "InputDevice"
- Identifier "Mouse0"
- Driver "mouse"
- Option "Buttons" "5"
- Option "Emulate3Buttons" "off"
- Option "Protocol" "ImPS/2"
- Option "ZAxisMapping" "4 5"
- Option "Device" "/dev/psaux"
-EndSection
-
-You'll want to find your mouse section (which may have
-a different Identifier -- just leave it alone) and edit that.
-The "Buttons", "Protocol", "ZAxisMapping", and "Emulate3Buttons"
-lines are all important.
+Intro(1) contains a list of man pages that describe new features
+or differences from Plan 9.
* Helping out
-If you'd like to help out, great!
-
-The TODO file contains a small list.
+If you'd like to help out, great! The TODO file contains a small list.
If you port this code to other architectures, please share your changes
-so others can benefit. See PORTING for some notes.
+so others can benefit.
Please use diff -u or CVS (see below) to prepare patches.
* CVS
You can use CVS to keep your local copy up-to-date as we make
-changes and fix bugs. The idioms explained here are pretty much
-all you need to know about CVS.
-
-To check out from the anonymous CVS repository, use
-
- cd /usr/local
- >$HOME/.cvspass
- cvs -d :pserver:anoncvs@cvs.pdos.lcs.mit.edu:/cvs login
- cvs -d :pserver:anoncvs@cvs.pdos.lcs.mit.edu:/cvs checkout plan9
-
-When prompted for a password, just hit enter.
-
-If there is already a /usr/local/plan9 directory (from a previous
-unpacking), remove it or move it out of the way. You need write
-access to /usr/local in order to run the checkout, but after that
-you'll only need write access to the plan9 subtree. I typically run
-the initial checkout as root and then chown -R rsc plan9 so that
-I can do things as rsc afterward.
-
-From then on, when you want to update, you can do
-
- cd /usr/local/plan9
- cvs update -dAP
-
-If there are conflicts between changes you have made locally
-and changes on the server, cvs will warn about them and leave
-them clearly marked in the updated files.
-
-If you change something and want to submit the change (please do!),
-you can run
-
- cd /usr/local/plan9
- cvs diff -u
-
-to generate the diff in a format that will be easy to apply.
-(You can also use this to see what you've changed.)
-
- cvs diff -D20040101 -u
-
-shows you differences txixt your tree and the repository
-as of January 1, 2004.
-
-Running the cvs commands in /usr/local/plan9 makes them
-apply to the whole tree. Running them in a subdirectory applies
-only to the code rooted there in the code.
-
-There's not much magical about /usr/local/plan9. If you
-check out the tree in some other directory, it should work
-just as well.
+changes and fix bugs. See the cvs(1) man page here ("9 man cvs")
+for details on using cvs.
-Thanks.
+* Contact
Russ Cox <rsc@swtch.com>