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Format fixes in 1990/jaw/README.md

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I did not check for typos and I believe I only fixed one. I will look
for typos at a later time.
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Cody Boone Ferguson committed 2023-04-09 05:10:17 -07:00
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@@ -1,28 +1,29 @@
# Best Entropy-reducer
James A. Woods
Research Institute for Advanced Computer Science
MS 230-5
NASA Ames Research Center
Moffett Field, CA 94131
USA
James A. Woods
Research Institute for Advanced Computer Science
MS 230-5
NASA Ames Research Center
Moffett Field, CA 94131
USA
Karl F. Fox
Morning Star Technologies, Inc.
1760 Zollinger Road
Columbus, OH 43221
USA
Karl F. Fox
Morning Star Technologies, Inc.
1760 Zollinger Road
Columbus, OH 43221
USA
Paul Eggert
Twin Sun Inc.
360 N. Sepulveda Blvd. #2055
El Segundo, CA 90245
USA
Paul Eggert
Twin Sun Inc.
360 N. Sepulveda Blvd. #2055
El Segundo, CA 90245
USA
## To build:
make all
```sh
make all
```
[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) fixed the script to
work properly in modern environments (to do with PATH not having '.' in it). He
@@ -40,14 +41,15 @@ Endoh](/winners.html#Yusuke_Endoh). Thank you Yusuke for your implementation of
To test the official C entry, one might try:
echo "Quartz glyph jocks vend, fix, BMW." | compress | ./btoa | ./jaw
```sh
echo "Quartz glyph jocks vend, fix, BMW." | compress | ./btoa | ./jaw
```
which should apply the identity transformation to a minimal
holoalphabetic sentence.
which should apply the identity transformation to a minimal holoalphabetic
sentence.
NOTE: Cody notes the above will not work under macOS. The `sh shark.sh jaw.*
README.md > receive` and following commands below do work with macOS after the
fixes he made.
Cody noted the above will not work under macOS. The commands in the judges'
comments do work in macOS after the fixes he made.
## Judges' comments:
@@ -55,19 +57,21 @@ fixes he made.
The program, in its base form, implements two useful utilities:
atob - ascii to binary conversion
zcat - decompression filter
Included with this entry is a shell script (with comments edited down
to reduce it to 1530 bytes) which implements the complete
shark utility. The script, shark.sh, contains a 'jaw.c' embedded
within it!
- `atob` - ascii to binary conversion
- `zcat` - decompression filter
Included with this entry is a shell script (with comments edited down to reduce
it to 1530 bytes) which implements the complete shark utility. The script,
shark.sh, contains a 'jaw.c' embedded within it!
The sender must have `compress` and `btoa`. To send, try:
sh shark.sh jaw.* README.md > receive
```sh
sh shark.sh jaw.* README.md > receive
```
The resulting file, 'receive', unpacks the input files
The resulting file, `receive`, unpacks the input files
even if the receiver lacks `uncompress` and `btoa`:
mkdir -p test
@@ -78,7 +82,7 @@ even if the receiver lacks `uncompress` and `btoa`:
## Authors' comments:
ABSTRACT
### ABSTRACT
Minimal, Universal File Bundling
(or, Functional Obfuscation in a Self-Decoding Unix Shell Archive)
@@ -92,63 +96,63 @@ even if the receiver lacks `uncompress` and `btoa`:
[anon., circa 1988, pre-Morris worm era]
Myriad formats have been proposed for network-mailable
data. A major difficulty undermining the popularity of most
file/message bundlers is that the sender assumes prior
installation of the computational dual of such bundling
software by the receiver. Command shell archives alleviate
this problem somewhat, but still require standardization for
the function of data compression and mail-transparency
encoding. On Unix, these coding format quandaries are over-
come by planting a novel Trojan Horse in the archive header
to perform negotiation-less decoding.
Myriad formats have been proposed for network-mailable data. A major difficulty
undermining the popularity of most file/message bundlers is that the sender
assumes prior installation of the computational dual of such bundling software
by the receiver. Command shell archives alleviate this problem somewhat, but
still require standardization for the function of data compression and
mail-transparency encoding. On Unix, these coding format quandaries are over-
come by planting a novel Trojan Horse in the archive header to perform
negotiation-less decoding.
Specifically, we outline the development of an extraordinarily compact
portable (un)bundler to (dis)assemble data-compressed,
binary-to-ASCII-converted, length-split, and checksummed directory structures
using standard Unix tools. Miniature versions of counterparts to a Lempel-Ziv
coder ('compress' or 'squeeze') and an efficient bit packet- izer ('btoa') are
compiled on-the-fly at mail destination sites where they may not already
exist. These are written in purposefully obfuscated-C to accompany
similarly-shrunk shell command glue. This resulting shell archiver is dubbed
'shark'.
Specifically, we outline the development of an extraordinarily compact portable
(un)bundler to (dis)assemble data-compressed, binary-to-ASCII-converted,
length-split, and checksummed directory structures using standard Unix tools.
Miniature versions of counterparts to a Lempel-Ziv coder ('compress' or
'squeeze') and an efficient bit packetizer ('btoa') are compiled on-the-fly at
mail destination sites where they may not already exist. These are written in
purposefully obfuscated-C to accompany similarly-shrunk shell command glue. This
resulting shell archiver is dubbed `shark`.
'Shark' procedure overhead consumes as few as three dozen shell lines (or
~1100 bytes), commensurate with the size of many Internet mail headers; it
`shark` procedure overhead consumes as few as three dozen shell lines (or
`~1100` bytes), commensurate with the size of many Internet mail headers; it
amortizes favorably with message size. 'Shark' is portable across Unix
variants, while the underlying technique is inherently generalizable to other
encoding schemes.
In the function-theoretic sense of minimal
Chaitin/Kolmogorov complexity, and within a modified Shannon
model of communication, the 'shark' effort aims to construct
a "shortest program" for source decoding in the Turing-
universal Unix environment.
In the function-theoretic sense of minimal Chaitin/Kolmogorov complexity, and
within a modified Shannon model of communication, the 'shark' effort aims to
construct a "shortest program" for source decoding in the Turing-universal Unix
environment.
----------------------------------------------
Oh, the shark has pretty teeth, dear--
And he shows them pearly white
Just a jackknife has Macheath, dear--
And he keeps it out of sight.
> Oh, the shark has pretty teeth, dear--
> And he shows them pearly white
> Just a jackknife has Macheath, dear--
> And he keeps it out of sight.
[Bertolt Brecht, Threepenny Opera]
> [Bertolt Brecht, Threepenny Opera]
----------------------------------------------
### Portability:
We have ported this program to a wide variety of systems. Among
these are:
SunOS 4.1 / Sun Sparcstation 1 (using both 'cc' and 'gcc 1.37.1')
SunOS 4.0.3 / Sun 3
BSD 4.3 / VAX 8650
SEIUX / Sumitomo Electric Ustation/S
Sony NEWS-OS 3.3 / Sony NEWS (fairly vanilla 4.3BSD)
System V.? / Hitachi 2050
System V.? / NEC EWS 4800
UNIOS-B / Omron Luna
Dynix / Sequent Balance ('cc' for Natl. Semi. base + 'gcc 1.36')
Unicos / Cray 2
- SunOS 4.1 / Sun Sparcstation 1 (using both 'cc' and 'gcc 1.37.1')
- SunOS 4.0.3 / Sun 3
- BSD 4.3 / VAX 8650
- SEIUX / Sumitomo Electric Ustation/S
- Sony NEWS-OS 3.3 / Sony NEWS (fairly vanilla 4.3BSD)
- System V.? / Hitachi 2050
- System V.? / NEC EWS 4800
- UNIOS-B / Omron Luna
- Dynix / Sequent Balance ('cc' for Natl. Semi. base + 'gcc 1.36')
- Unicos / Cray 2
### Obfuscation:
We (the authors) feel this program is obfuscated for the
following reasons:
@@ -172,32 +176,32 @@ preserved at amazing cost for sheer perversity.
5. Many, many micro obfuscations below, honed over three years time, in shell as
well as C. Ask about the 'tar' pit escape, the argv[0] flip, Paul's &4294967295
portability hack, the "void where prohibited by flaw" fix, the scanf()
spacesaver, shift shenanigans, signal madness, exit()ing stage left, and
space-saver, shift shenanigans, signal madness, `exit()`ing stage left, and
source-to-source transformations galore.
For extra credit:
### For extra credit:
Construct 'sharkmail', to auto-split sharkives into mailable
segments and mail them. Here's a simple one, which could be
extended to enable auto-reassembly with one shell cmd at the
far end.
------------------------ cut here for sharkmail -----------------------
#!/bin/sh
m=$1; shift
shark $* | split -800 - /tmp/shark$$
n=`ls /tmp/shark$$* | wc -l | sed 's/ *//'`
p=0
for f in `ls /tmp/shark$$*`
do
p=`expr $p + 1`
mail -s "bundle ($p of $n) from '`whoami`'" $m < $f
done
rm /tmp/shark$$*
------------------------ end of sharkmail -----------------------------
```sh
#!/bin/sh
m=$1; shift
shark $* | split -800 - /tmp/shark$$
n=`ls /tmp/shark$$* | wc -l | sed 's/ *//'`
p=0
for f in `ls /tmp/shark$$*`
do
p=`expr $p + 1`
mail -s "bundle ($p of $n) from '`whoami`'" $m < $f
done
rm /tmp/shark$$*
```
Shark history:
### Shark history:
May 1987: Karl Fox introduces 1023-byte zcat.c to USENET.
It's too late for the 4th IOCCC.