#! /bin/bash
# justify text / usage: just

# option check and set formatter
while getopts :r:l:c: opt
do
	case $opt in
	r)	flg=$opt; n=$OPTARG; fmt="printf \"%${n}s\\n\"" ;;
	l)	flg=$opt; n=$OPTARG; fmt="printf \"%-${n}s\\n\"";;
	c)	flg=$opt; n=$OPTARG;;
	*)	echo "usage: $0 [-rcl WIDTH]"; exit 1;;
	esac
done

# print stdin with format
while read buf
do
	if [[ $flg = 'c' ]]; then
		let n1=n/2
		let n2=${#buf}/2
		let n3=n1+n2
		fmt="printf \"%${n3}s\\n\""
	fi
	eval "$fmt \"$buf\""
done