Archive
Help Solve an Open Murder Case – (Seriously?)
Cryptanalysts
Part 2: Help Solve an Open Murder Case03/29/11
On June 30, 1999, sheriff’s officers in St. Louis, Missouri discovered the body of 41-year-old Ricky McCormick. He had been murdered and dumped in a field. The only clues regarding the homicide were two encrypted notes found in the victim’s pants pockets.
Despite extensive work by our Cryptanalysis and Racketeering Records Unit (CRRU), as well as help from the American Cryptogram Association, the meanings of those two coded notes remain a mystery to this day, and Ricky McCormick’s murderer has yet to face justice.
“We are really good at what we do,” said CRRU chief Dan Olson, “but we could use some help with this one.”
In fact, Ricky McCormick’s encrypted notes are one of CRRU’s top unsolved cases. “Breaking the code,” said Olson, “could reveal the victim’s whereabouts before his death and could lead to the solution of a homicide. Not every cipher we get arrives at our door under those circumstances.”
Learning Emacs – Ch 2 (Editing)
Chapter 2 – Editing
A. Movement
1. Characters
C-p (previous-line)
C-n (next-line)
C-f (forward-character)
C-b (backward-character)
2. Words
M-f [forward a word]
M-b [backward a word]
3. Lines
C-e [end of the line]
C-a [beginning of the line]
4. Sentences
M-a [move backward one sentence]
M-e [move forward one sentence]
5. Screen
C-v or PgDown Key [page down]
M-v or PgUp Key [page up]
6. Buffer
M-> or End Key [end of a buffer]
M-< or Home Key [beginning of a buffer]
7. To a specific line
M-x goto-line Enter n Enter
M-x goto-char Enter n Enter
B. Repeating Commands
M-n (digit-argument) eg M-500 C-n [move the cursor down 500 times]
C. Deleting Text
C-d (delete-character)
M-d (kill-word)
C-k (kill-line)
M-k (kill-sentence)
C-y (yank) [restore what you deleted]
D. Undo
C-_ or C-x u
Learning Emacs – Ch 1 (Basics)
Objective: Learn Emacs by reading this book. “Learning GNU Emacs, 3rd Edition By Debra Cameron, James Elliott, Marc Loy”
Chapter 1 – Emacs Basics
Open a file C-x C-f (find-file)
Save a file C-x C-s (save-buffer)
C-x C-w [Equivalent of save as]
Quit C-x C-c
Help C-h
C-h ? [list of options]
C-h t [tutorial]
C-h k (describe-key) C-h C-x i [ie describe the key for inserting a file.
C-x i (insert-file) ]
C-h f (describe-function) C-h f find-file
screen – copy command
When using screen. To scroll up and view “display history” 🙂
C-a esc (copy) Enter copy/scrollback mode.
To leave scrollback mode press ESC
using join to merge files
$cat file1
2011-03-01,0 2011-03-02,0 2011-03-03,0 2011-03-04,0 2011-03-05,0
$cat file2
2011-03-01,13400 2011-03-02,1730 2011-03-05,7593
To merge the two files so that the final file has all the rows in file1 use
$join -t’,’ -1 1 -2 1 -a 1 -e ‘0’ -o ‘1.1,2.2’ file1 file2
2011-03-01,13400 2011-03-02,1730 2011-03-03,0 2011-03-04,0 2011-03-05,7593
An excerpt from info join
-a FILENUM
print unpairable lines coming from file FILENUM, where FILENUM
is 1 or 2, corresponding to FILE1 or FILE2-e EMPTY
replace missing input fields with EMPTY-o FORMAT
obey FORMAT while constructing output line-t CHAR
use CHAR as input and output field separator-1 FIELD
join on this FIELD of file 1-2 FIELD
join on this FIELD of file 2
Useless use of cat
http://partmaps.org/era/unix/award.html
Above link looks dead.
But a search of “Useless Use of cat” gave the following results:
http://www.smallo.ruhr.de/award.html
https://en.wikipedia.org/wiki/Cat_%28Unix%29#Useless_use_of_cat
Writing 7zcat (works like zcat on *.7z files)
Copied /bin/zcat to a file called /bin/7zcat
#!/bin/bash
PATH=${GZIP_BINDIR-'/bin'}:$PATH
exec 7z e -so -bd "$@" 2>/dev/null | cat
pseudo-scripter 