Unofficial FAQ: Re: How to view the art???

Hello!

Some remarks about the FAQ (thanks, John!!!):

John G Poupore (jgp...@rodan.syr.edu) wrote:

: --------WHY CAN'T I SIMPLY POST ANIMATIONS DIRECTLY ON THE USENET? 
: 	THIS is an important question (very good, Ian.  You've been 
: 	paying attention.)  Don't bet your life on this but I'm pretty 
: 	sure it is accurate.  When you post a letter, newsreaders 
: 	automatically filter out the Escape characters.  So when you 
: 	download the animation, it doesn't say "<ESC>[L" but "^[L" or 
: 	something, which means ZIPPO (Blip!) to a vt100 terminal.
: 	THAT IS WHY YOU MUST _ALWAYS_ (no, I mean always) UUENCODE animations
: 	before posting them (notice I said animations.  Normal pictures,
: 	of course, need no special attention besides artistic talent. :)
: 	If you don't uuencode your animation, people cannot view the
: 	animation, making it a BIG waste of a ton of people's money.(It
: 	is possible to rebuild, but I can't imagine many people will
: 	want to go through the trouble)

In fact, very often all the control characters (chars 0-31), sometimes
even trailing spaces are stripped. The end-of-line-conventions can
make CR's (13) and LF's (10) modified (end of line conversion).
And some hosts delete bytes with bit 7 set (or strip that bit).
That's the problem why uuencode is needed.

: --------WHAT IS UUENCODEing?
: 	uuencode is a program which takes files and encodes them in such
: 	a way that I have no idea, but the important thing is that there
: 	are only printable characters, I believe.  So therefore, they
: 	can be sent on the USENET, without the Escape characters being
: 	removed.

The charset produced by uuencode is 33-96, all standard ASCII printable
characters which should be no problem.

UUENCODE works just like the following:
begin <mode> <filename>
Maaaabbbbccccddddeeeeffffgggghhhhiiiijjjjkkkkllllmmmmnnnnoooo
...
xaaaabbbbcccc

end

aaaa - oooo are encodings of 3 bytes each group. uuencode divides those
3 byte groups in 4 pieces of each 6 bits. 6 bits (call them y) are encoded
by the char (32+y). If the resulting char is 32 (space) it is substituted
with ` (char 96) in newer versions of uuencode, so that stripping
trailing spaces is no more a problem.

The first char is the number of bytes encoded in a line, written in
the same 32+y scheme. Usually uuencode encodes 45 bytes (hence char
32+45 = capital M in front of nearly each line) in each line. Only the
last line (that with xaaaabbbbcccc above) contains less information.
After the last line, there is an empty line, then the keyword end
(in lowercase).

<filename> is the name of the file created while decoding, <mode>
is the mode of that file (in usual octal notation).

: 	A uuencoded file looks SOMETHING like this:

: 	begin 664 filename.vt100
: 	MSDJKFXCNVNXLL!@#)(*S)F(SDF*CVXHVKS*)XUCV)X*(CV*UX)*FDUVD)*VXC
: 	M*OVD()*FV)S*VU)X*VUX)C*VUX)*VUX)*VSUDV*)XCUVX)CV*XCV*)XCV*)XC
: 	.
: 	.
: 	end

: 	To find out more about "uuencode", consult your local friendly
: 	man pages.  you probably won't find anything.

: 	Type uuencode <filetoencode> <newname>
: OR      uuencode filetoencode nameofdecodedfile >diskfilename.uuc
:         (first one dumps it to the screen on my system.)

uuencode <filename>
encodes stdin to stdout, writing <filename> into the header.

uuencode <filename1> <filename2>
encodes <filename1> to stdout, writing <filename2> into the header.

Hence uuencode <filename2> < <filename1>
does the same as uuencode <filename1> <filename2>

Usually one redirects stdout to something like foobar.uu

: --------HOW DO I GET AN ANIMATION OFF THE USENET?
: 	1) Well, first, you must save it in a file.  Try the magic keys "h"
: 	and "?" to try to get help.  Say you save it to the file BLOOP.

Often the command to save is (obviously) 's'.

: TO SLOW THESE THINGS DOWN IN UNIX:
: dd if=<filename> bs=1

That's very important for MANY animations!!!! You could note this
in the section about viewing an animation.

: [Torture test]

That is fine and uses really MANY vt100-features! Thanks!

Regards, Felix.
--
Felix Schroeter -- uk1...@rz.uni-karlsruhe.de -- dl6...@db0sao.ampr.org