#!/bin/bash
rm -f foo

echo non-sparse original runs quickly
cat $(which emacs-nox) >/dev/null
time $(which emacs-nox) -Q --batch --eval '(kill-emacs)'

echo sparse copy can be read quickly from fs cache
cp --sparse=always $(which emacs-nox) foo
cat foo >/dev/null
time cat foo >/dev/null

echo sparse copy slow-to-run in spite of being cached
time ./foo -Q --batch --eval '(kill-emacs)'

echo sparse copy no longer fully cached
time cat foo >/dev/null

echo filling all holes makes sparse penalty worse
cp --sparse=never $(which emacs-nox) foo
cat foo >/dev/null
time ./foo -Q --batch --eval '(kill-emacs)'