Ben Greenman bennn

This can reduce files to ~15% of their size (2.3M to 345K, in one case) with no obvious degradation of quality.

ghostscript -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/printer -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

Other options for PDFSETTINGS:

/screen selects low-resolution output similar to the Acrobat Distiller "Screen Optimized" setting.
/ebook selects medium-resolution output similar to the Acrobat Distiller "eBook" setting.
/printer selects output similar to the Acrobat Distiller "Print Optimized" setting.
/prepress selects output similar to Acrobat Distiller "Prepress Optimized" setting.

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

There are always 24 hours in a day.
February is always 28 days long.
Any 24-hour period will always begin and end in the same day (or week, or month).

So, you just cloned an existing project's repo and you run bundle install but you got the error: rbenv: version x.x.x is not installed....

What the issue means? The project uses a specific ruby version that you do not have on your system.

Here's how to fix it:

rbenv install x.x.x

	/*
	* A simple libpng example program
	* http://zarb.org/~gc/html/libpng.html
	*
	* Modified by Yoshimasa Niwa to make it much simpler
	* and support all defined color_type.
	*
	* To build, use the next instruction on OS X.
	* $ brew install libpng
	* $ clang -lz -lpng16 libpng_test.c

	#lang racket
	;; Updated plot library required, https://github.com/alex-hhh/plot/tree/ah/interactive-overlays
	(require plot pict)

	;; Helper function to add a pict as a plot overlay -- don't want to add "pict"
	;; as a dependency to the "plot" package
	(define (add-pict-overlay plot-snip x y pict)
	(send plot-snip add-general-overlay x y
	(lambda (dc x y) (draw-pict pict dc x y))
	(pict-width pict)

	#lang scratch

	(require compiler/zo-structs
	(for-syntax compiler/zo-structs
	racket/struct-info))

	(begin-for-syntax
	(define-values (exports expsyn)
	(module->exports 'compiler/zo-structs))
	(define struct-types

	#lang racket
	(require racket/draw
	racket/promise
	plot
	plot/utils
	pict)

	;; These color maps correspond to the Matplotlib 3.0.3 qualitative color maps
	;; with the same names. See
	;; https://matplotlib.org/examples/color/colormaps_reference.html

	#!/usr/bin/env ruby

	HELP_STR = "Usage: $ remove_rightslink_images file1.pdf file2.pdf"

	begin
	require 'hexapdf' # HexaPDF is AGPL licensed according to https://hexapdf.gettalong.org/
	rescue LoadError
	if system("gem install --no-doc hexapdf")
	Gem.clear_paths
	require "hexapdf"