• use (ref)bash:unofficial-strict-mode
• The most important variables are:
  • $@ - the name of the target
  • @< - the name of the first prerequisite
  • $^ - the name of all prerequisites, separated by spaces
  • $* - the stem that was matched when using % patterns
  • $(@D) - the directory part of the target

Preamble​

SHELL := bash
.ONESHELL:
.SHELLFLAGS := -eu -o pipefail -c
.DELETE_ON_ERROR:
MAKEFLAGS += --warn-undefined-variables
MAKEFLAGS += --no-builtin-rules

ifeq ($(origin .RECIPEPREFIX), undefined)
$(error This Make does not support .RECIPEPREFIX. Please use GNU Make 4.0 or later)
endif
.RECIPEPREFIX = >

References​

• Davis-Hansson, Jacob. “Your Makefiles Are Wrong.” Jacob Davis-Hansson on Tech (blog), December 15, 2019. https://tech.davis-hansson.com/p/make/.
• “Automatic Variables.” In GNU Make Manual. Free Software Foundation. Accessed March 2, 2022. https://www.gnu.org/software/make/manual/html_node/Automatic-Variables.html.

• subclass of Applicative

Functions​

class Monad m where
(>>=)  :: m a -> (  a -> m b) -> m b
(>>)   :: m a ->  m b         -> m b
return ::   a                 -> m a

Operators​

• (>>=) is infix form of bind

Laws​

return a >>= k                  =  k a
m        >>= return             =  m
m        >>= (\x -> k x >>= h)  =  (m >>= k) >>= h

References​

• Monad on the HaskellWiki.

Philosophy​

• modular vs. monolithic
• do one thing and do it well
• composable
• output of one program becomes input to another
• avoid scope creep - keep it small, and make a new tool

Predefined Environment variables​

:::(envvar) EDITOR

• Value must be an editor application that can be used from the command line :::

:::(envvar) PATH :::

External Links​

• Unix Philosophy on Wikipedia
• O'Reilly Unix Power Tools, Third Edition, Section 35.5

• a.k.a. Semantic Linefeeds
• put each sentence on own line
• works well with source control e.g. git
• easy to move sentences around
• originally described by Buckminster Fuller in the 1930s

References​

• Asciidoc Recommended Practices on Asciidoc.org
• Ventilated Prose on A Programmers Place
• Semantic Linefeeds on rhodesmill.org

:a.k.a.: Standard Score

• a way to compare two stats together
• a z-score is not interpretable without context
• equal to the number of standard deviations of difference between a data point and the mean

:::INFO see also

• Standard Score on Wikipedia :::

Formula​

$$
Z = \frac{x-\mu}{\sigma}
$$

• $Z$ = standard score
• $x$ = observed value
• $\mu$ = mean of the sample
• $\sigma$ = standard deviation of the sample

A coworker relayed this definition of diplomacy:

Diplomacy is the art of of telling people to go to hell in such a way that they ask for directions

This is a variation of a common quote, typically misattributed to Winston Churchill.¹

The earliest version was posted anonymously to the "St. Louis Star-Times" in 1937.²

A diplomat is a person who can tell you to go to hell in such a tactful way that you’ll look forward with pleasure to making the trip.