Selected source code

Things I'd like to share which might be useful to you, but which don't quite merit their own page.
Most of these things should have man pages but don't (yet).

System utilities

nile
A derivitive of rio(1) with several changes:
stat.c - man (source, html)
A utility to print out various information about a file. Often easier than parsing or converting ls -l or similar.
mc.c
A modified version of mc which uses nile's new winfont file to get the font for the current window, reducing alignment errors when cpuing.
winwatch.c
A modified version of winwatch which adds a menu on botton 3 with Show, New, Delete, and Hide items. Mostly intended for use with nile's -m, but works regardless.
sping.c
Report how long it takes to stat a file, in microseconds. Use -f filename to specify the file; it defaults to ".". This was intended for getting a quick-and-dirty benchmark on some remote file systems, but doing sping -f '#/' turned up some interesting performance differences between VPS providers. If specified, -i interval will cause it loop for interval seconds; interval may be fractional.
The dumb name stands for "stat ping".
trickle.c
This copies input to output, inserting a delay between each byte (the code is half there to make the size of the unit copied configurable, but I didn't need it so it's unfinished). I used this to avoid flooding a serial link which lacked flow control.
waitloop
Run a command in a loop, with a minimum delay. Avoid chewing up the machine on commands with transient failures.

Date, time, and calendar related utilities

datefmt — man (source, html)
Like the + arguments in the unix date command, but as a stand-alone program. This implements most of the POSIX set, except for locales (EO) and the year-by-weeks stuff (gGUVW), with several extentions from other systems and a couple local ones. Use like "datefmt %Y-%M-%d".
Available in both C and Limbo versions:
datefmt.c — datefmt.b
mayan.c
Like datefmt, but for the Mayan calendar. Implements the Tzolk'in (260-day count), Haab' (365-day count), and the Long Count.
I am not 100% certain about all these conversions; don't use this for academic work without verifying them first.
timestamp.c
Copy input lines to output, prepending a timestamp. By default, the timestamp is fractional seconds since timestamp started; -i instead gives the time since the last line, and -f format prints the current date using datefmt, above.
This is modified from work by sqweek on IRC.

Graphics programs

The programs in this section all run on Plan 9 and under plan9port; where relevant, they detect unix by looking for $service being empty or set to "unix".
Download the source and documentation for this section.
jocelyn.c
Have you ever wondered what the cover of Joy Division's Unknown Pleasures would have looked like if it had been done by a Plan 9 user? Wonder no more! Pull down the original pulsar data and save it to $home/lib/pulsar.csv, and create your very own ridgeline plots of a stellar phenomenon. Options are -x and -y for x and y scaling, -o for the offset between lines, and -t for the line thickness. There's a bit of trial and error to find nice values for a given display; the defaults work nicely on my macbook under p9p, but my qemu terminal looks better with -x 2 -y 2 -o 8 -t 1.
wordwrap.c, wordwrap.h — man (source, html)
Implements word wrapping under draw(3). Given a string, font, insertion point, and margin, it'll try to fit each word into screen, which must be a defined global (as is set up by initdraw(2)).
litclock and marquee, below, depend on this.
litclock.c — man (source, html)
Modeled after Johannes Enevoldsen's Literature Clock, it will display a quote reflecting the current time. You'll need a quote database at $home/lib/litclock.csv; I use Johannes' but since his runs in a browser, his database has a few <br>-style breaks in there. Fix it by running the database through "sed 's/\<br ?.?\>/\\n/g'". Doesn't handle missing runes in the source text nicely.
marquee.c — man (source, html)
Read input and display it in a large font, wrapping text to the window. Use like 'fortune | marquee'.
This was mostly written to get the word wrapping right for use in litclock, which has now been turned into the library above, but this is fun, too.
Doesn't handle missing runes in the source text nicely.
magicclock.c — man (source, html) — screenshot (Plan 9, — plan9port)
Display a "magic clock": a letter grid that "highlights" words corresponding to the current time. Option -c will cause it to center the clock in its window.
colorsteps.c
Calculate and display a color ramp calculating a set number of intermediary colors between the specified colors. Usage: colorsteps [-D] [-s nsteps] color1 color2 [colorN...]
-D increases the debugging level (up to 2 are meaningful today), -s sets the number of steps between specified colors (default 4), and you specify checkpoint colors (at least two) as RRGGBB or RRGGBBAA hex values.
Tap 'q' in the window to exit.
slideshow—Coming Soon
Slide presentations in native Plan 9 C using draw().

Network programs

vernam.c
A version of aux/trampoline which creates a "Vernam tunnel" — a giant One Time Pad for all the network traffic. It's sort of logistically difficult to set up securely, but offers theoretically unbreakable security for your traffic.
Inspired by Vernam Tunnel.
prowl.c
Send a message to Prowl, to get arbitrary notifications to iOS devices. I use this in my pipemail file to get notifications about email from folks I don't want to miss, to send URLs to my iPad, and for system notifications like resource exhaustion.
ncp
A re-implementation of ncp, but without the broadcast bits. Often the simplest way to get a file from point A to point B.

Wiki utilities

wiki
A read-only command line wiki client. 'wiki -l' lists the pages, 'wiki foo' prints article foo, 'wiki foo bar' looks for an article called "foo_bar", then "foo-bar", then separate "foo" and "bar" articles. See my post on 9fans for more detail.
I have a version for both Plan 9 and plan9port:
wiki for Plan 9 — wiki-p9p for plan9port
wikiedits
Mail interested parties when the wiki has new edits.
whatsnewwiki
Update the "What's New" wiki page with what's new on the wiki. Best to only do this on a wiki you manage, to avoid thrashing. Change your name in here if you use this.
contrindx
[This one needs to be updated before it'll work again.] Update the wiki's "Contrib Index" page with an index of the "contrib" package system. Best to only do this on a wiki you manage, to avoid thrashing. Change your name in here if you use this.
This was based on work by uriel.

Toys and trivialities

iveble
Mostly a port of a twitter joke by thingskatedid. Inconclusive and illimitable.
s7r — shortener
An awful toy to take a line of text and generate substitutions like "i18n" for "internationalization". These are bad and you should not use them. Available, inexplicably, for both Plan 9 and plan9port:
s7r for Plan 9 — s7r-p9p for plan9port
Also — again, inexplicably — available as a service:
: ; echo 'S7R: abbreviate as a service' | nc 9srv.net 50002
S7R: a8e as a s5e
: ; echo 'Please finance this endeavor.' | nc 9srv.net 50002
P4e f5e this e6r.
curslife.c
Conway's Game of Life... played in your mouse cursor. Adapted from games/life; the options are the same.
writecursor.c
A trivial test while writing curslife; mostly just an example of the formats for setting your cursor.

See also: txtpunk.com/.