#!/bin/sh

m="$(date +%m)"
d="$(date +%d)"
y="$(date +%y)"

# Trying to make a regex that will match expac's date format

# 1. create ranges based on command line arguments
# 2. change this to \(n-2\|n-1\|n\)
# 	I. 	generate sequence
# 	II. remove trailing space
# 	III.translate space to '\|'
#	IV. wrap everything in '\( ... \)'
# 	V.	shift command line arguments
# repeat 2. for month and year
# 3. seq outputs a newline, translate this to slash
# 4. remove trailing slash
regex="$(for var in m d y
do
	seq -w -s ' ' $((${!var} - ${1:-0})) ${!var} |
		sed 's/ /\\|/g;s/.*/\\(&\\)/'
	shift 2>/dev/null
done |
	tr '\n' '/' | 
	sed 's/.$//')"

expac -t %D '%l %n' | 
	grep "$regex" |
	sort -k 2 -t '/' -n