Charts for a study
The wall beside a desk is prime reference space. Whatever hangs there gets consulted without a browser tab, without a search, and without the several minutes a search usually turns into.
What suits it is the material used mid-task: status codes and CSS properties, the working areas of Git, unit prefixes and paper formats, Morse and the phonetic alphabet, the Greek letters that turn up in every formula, and the size conversions wanted the moment something is ordered from abroad.
A4 is usually enough at desk distance. Print on white, on whatever printer is already in the room — that is what these files are built for.
SEMANTIC VERSIONING
what each of the three numbers means, what may follow them, and the order versions stand in
QUOTING IN THE SHELL
29 characters named by the standard, 4 ways to take the meaning off them — and the 3 characters where double quotes stop
read: A LINE INTO VARIABLES
The last variable takes the whole rest of the line, inner spaces and all; without -r the backslash disappears, and a line with no final newline gives status 1 — although the variable is already full
INSERTION SORT
the way cards are ordered in the hand · the trace of one real run
QUICKSORT
splitting around a pivot · the trace of one real run
TWO-CAMERA SPEAKER SETUP
the lighting triangle and where each of the 2 cameras stands · the floor plan from above
THREE-CAMERA SPEAKER SETUP
the lighting triangle and where each of the 3 cameras stands · the floor plan from above
THE SELECT STATEMENT
8 clauses in the order you write them — and the order they take effect in
SUBNET MASKS
from /0 to /32: the mask, how many addresses a block holds, and how many of them go to hosts
THE CONDITIONS OF TRAP
FIVE conditions from the standard — EXIT and four signals — and three extensions a conformant shell refuses
THE UMASK
The file mode creation mask: the nine bits it clears, five arguments that name opposite things — and why umask 022 is not chmod 755
UML DIAGRAMS
the fourteen kinds, and the notation a class diagram is made of