Toby's recent interest in GIFs has revived our own. How do "they"
translate all those "specifications" into "code?" How, in general, do
words become "data?"
We took Toby aside yesterday and got him registered in S. Portland's
Computer Science program. This morning he walked away with yet another
PhD, this time in Software Engineering. His knowledge would fill volumes
but he's been kind enough to give us a few minutes of his precious time
to tell us just one aspect of GIFs that he learned.
He was looking at DeeDee's little Christmas Tree (which she was
disappointed to learn sometimes didn't sparkle anymore) and thought it
might be interesting to investigate the .gif that somehow captured it.
He'd heard TcT'd knocked out a "file dumper" which lets you look at
files right down to the bare metal, so he used it on hers and was
startled to discover the letters GIF hiding inside.
Rec 0
47 49 46 38 39 61 64 00 6E 00 F7 FE 00 00 00 00 GIF89ad.n.......
00 18 00 08 18 21 10 10 10 21 00 00 1B 18 08 16 .....!...!......
1C 14 18 21 21 10 26 0D 0C 36 12 00 52 00 10 54 ...!!.&..6..R..T
0F 00 73 00 0D 77 0B 00 94 00 0D 9C 0A 29 08 00 ..s..w.......)..
39 00 00 4A 00 00 5A 03 00 47 12 0A 66 10 04 4D 9..J..Z..G..f..M
21 0B 58 48 0D 7B 00 00 7B 22 00 8F 18 00 AE 17 !.XH.{..{"......
01 7B 4A 18 8C 44 08 A5 39 04 AE 4D 0C 1A 28 2D .{J..D..9..M..(-
34 33 2D 31 31 49 3A 4A 3D 32 68 3D 3E 50 56 45 43-11I:J=2h=>PVE
Rec 1
60 67 58 5E 48 5C 6C 5E 5A 6C 70 5C 84 81 89 71 `gX^H\l^Zlp\...q
4B 73 79 79 73 8C 83 93 91 7E 00 7B F7 40 85 B6 Ksyys....~.{.@..
73 8C 94 73 98 9C 7B 90 98 7B 9C 9C 7B 9C A5 73 s..s..{..{..{..s
9C AD 94 5A C7 8D 97 98 90 9C 9C 9C 9C 9C 7B 9C ...Z..........{.
AD 7B A5 A5 84 9C A5 90 A2 A5 00 AD 00 00 B5 00 .{..............
00 BD 00 0C BF 0C 00 D6 00 0C D6 0C 00 E7 00 0A ................
E4 0D 00 EF 00 00 F7 00 00 FF 00 08 EF 08 08 F7 ................
08 10 F3 10 08 FF 08 10 FF 10 2A D5 2C 2A EC 2A ..........*.,*.*
Press Enter ...
He then got to thinking that all that other stuff was probably some
complicated code which somehow got turned into green, light blue, snow
flakes falling etc. etc.
At S. Portland U. they taught him that Scientists try to generalize
stuff so he wondered, "What about .jpgs? .pdfs? .zips? etc. etc.?!" He
got right to work, "dumping" files like there was no tomorrow. This is
what he saw.
For Max's milkweed.jpg
Rec 0
FF D8 FF E0 00 10 4A 46 49 46 00 01 01 01 00 48 ......JFIF.....H
00 48 00 00 FF DB 00 43 00 05 03 04 04 04 03 05 .H.....C........
04 04 04 05 05 05 06 07 0C 08 07 07 07 07 0F 0B ................
0B 09 0C 11 0F 12 12 11 0F 11 11 13 16 1C 17 13 ................
14 1A 15 11 11 18 21 18 1A 1D 1D 1F 1F 1F 13 17 ......!.........
22 24 22 1E 24 1C 1E 1F 1E FF DB 00 43 01 05 05 "$".$.......C...
05 07 06 07 0E 08 08 0E 1E 14 11 14 1E 1E 1E 1E ................
1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E ................
Rec 1
1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E ................
1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E 1E FF C0 ................
00 11 08 00 A0 00 F5 03 01 22 00 02 11 01 03 11 ........."......
01 FF C4 00 1C 00 00 02 02 03 01 01 00 00 00 00 ................
00 00 00 00 00 00 05 06 04 07 00 02 03 01 08 FF ................
C4 00 3D 10 00 02 01 02 04 04 04 04 05 04 01 04 ..=.............
01 05 01 00 01 02 03 04 11 00 05 12 21 06 31 41 ............!.1A
51 13 22 61 71 14 32 81 91 07 A1 B1 C1 F0 23 42 Q."aq.2.......#B
Press Enter ...
Not exactly JPEG, or JPG, but he spotted JFIF and, after dumping a few
more .jpgs, they ALL had that same, what he decided to call, "signature"
JFIF at the beginning.
He couldn't wait to try this idea on the venerable tspeek.zip.
Rec 0
50 4B 03 04 14 00 00 00 08 00 A2 6E 2D 39 28 6D PK.........n-9(m
4D 0D 82 01 00 00 3A 03 00 00 04 00 15 00 74 73 M.....:.......ts
2E 68 55 54 09 00 03 00 FE CB 48 04 FE CB 48 55 .hUT......H...HU
78 04 00 E8 03 E8 03 7D 51 CB 6A C3 30 10 BC FB x......}Q.j.0...
2B 16 7A 49 82 D2 38 69 D3 8B 4F A5 8F 53 1F A7 +.zI..8i..O..S..
42 C1 98 62 5B AB 44 20 4B 46 DE BC FE BE 92 65 B..b[.D KF.....e
B9 2E 94 5E 2C ED 68 66 76 76 9D AC 16 40 DD F5 ...^,.hfvv...@..
1E 96 A0 6C 05 8B 55 92 5C 71 14 52 23 BC DE 7F ...l..U.\q.R#...
Rec 1
3E C0 5D 9A A6 53 E4 11 B6 53 E4 E9 FD 19 96 EB >.]..S...S......
B1 7C FB 78 79 81 34 49 EA 7D 69 81 28 F7 16 45 .|.xy.4I.}i.(..E
06 BE 87 A9 10 81 F0 4C 50 1D 84 40 EB 5B F5 34 .......LP..@.[.4
FD 8B A7 F1 F4 0F 97 B8 A7 3E 4E 2D B9 AC 49 1A .........>N-..I.
5D DA CB 84 2C 35 01 6A 6E 84 90 0A B3 A0 3D A2 ]...,5.jn.....=.
CD B7 41 E9 AE 9D D3 44 A6 2B 2B D3 21 3B 68 B2 ..A....D.++.!;h.
A5 1E E8 24 F2 DB 6D C1 88 8B 7C BD E9 4F ED 02 ...$..m...|..O..
F9 7B 96 8C CD BD BD 2E 1B 64 D3 18 11 EC 9C 3F .{.......d.....?
Press Enter ...
Once again, he discovered something common in every .zip he "dumped."
There was that PK thing in the first two "bytes." (He impressed his
students (for he was now a tenured Professor at S. Portland U. and used
words like "byte" when he lectured now.)) Upon further research he
learned about a guy named Phil Katz who apparently invented ZIP files.
That PK must be what has survived.
He only had time for one more so he looked around for a .pdf. He knew
people liked to use these when they wanted their "documents" to be
"portable." (He was really getting into the Comp. Sci. lingo now and it
was fun using cool words like "document" and "portable.")
Rec 0
25 50 44 46 2D 31 2E 34 0A 25 C7 EC 8F A2 0A 35 %PDF-1.4.%.....5
20 30 20 6F 62 6A 0A 3C 3C 2F 4C 65 6E 67 74 68 0 obj.<</Length
20 36 20 30 20 52 2F 46 69 6C 74 65 72 20 2F 46 6 0 R/Filter /F
6C 61 74 65 44 65 63 6F 64 65 3E 3E 0A 73 74 72 lateDecode>>.str
65 61 6D 0A 78 9C AD 59 DF 73 9B 46 10 7E E7 AF eam.x..Y.s.F.~..
58 AB 93 20 DB 08 C3 81 F8 11 85 A4 CD 4C 92 87 X.. .........L..
76 A6 4D AD E9 8B D0 83 8C 4E 12 16 02 05 B0 15 v.M......N......
4F A7 FF 7B F7 0E 70 25 0F A9 F7 3C B1 47 02 C1 O..{..p%...<.G..
Rec 1
DD 7E 7B 7B FB 7D 7B 1C 5F C1 32 99 0B 96 F8 EF .~{{.}{._.2.....
4E 92 9D 76 F5 A7 0F EB 4A B3 E0 33 7E D6 DA 57 N..v....J..3~..W
CD 35 6D CF F3 7C 79 FF F8 3C D9 C1 87 29 36 0F .5m..|y..<...)6.
C0 33 C7 CC F7 03 98 AE 34 5B DE B2 C1 75 4C CB .3......4[...uL.
77 5D F0 2D DB 1C DB 0E 4C 77 DA D0 3E 9F DE 62 w].-....Lw..>..b
7B 1B EF 5B 66 E0 87 9E EC 10 98 B6 E3 8A 6E D3 {..[f.........n.
A5 36 BC BA 80 BA DA 73 BE 35 13 18 41 56 DE C0 .6.....s.5..AV..
C5 55 D3 EB 04 65 D4 F5 1A 49 4B 41 20 3B B3 E7 .U...e...IKA ;..
Press Enter ...
Sure enough! There was a bunch of stuff he didn't quite understand, but
that %PDF sure looked like a "signature" to him.
Professor Toby was onto something.