#!/bin/sh

## Read words from stdin, write to stdout in a column.
##
## Usage:
## See the variable named usage, below
##
## Blank lines are unchanged.
## Assumes each word is shorter than the desired width.

errx() {
	echo "$@" >&2
	exit 1
}

#
# Parse the command line
#
usage="usage: $0 "'[ -e | --email ] [ -w WIDTH ] [ file ]'
TEMP=`getopt -o ew: --long email,width: -n 'No way, man' -- "$@"`
if [ $? != 0 ] ; then errx "Terminating..."; fi
# Note the quotes around `$TEMP': they are essential!
eval set -- "$TEMP"

eflag=""
width=72
period_space=0
while true ; do
	case "$1" in
		-e|--email) eflag=yes ; shift ;;
		-w|--width) width=$2 ; shift 2;;
		--) shift ; break ;;
		*) echo "Internal error!" ; exit 1 ;;
	esac
done
#echo "Remaining arguments:"
#for arg do echo '--> '"\`$arg'" ; done

n=$width
[ "$n" -gt 0 ] || errx "$usage"
infile=""
if [ $# -gt 0 ] 
then
	infile=$1
	if [ ! -r "$infile" ]
	then
		errx "not readable: $infile"
	fi
fi
	

cat $infile | { ## start of filter
#
# Filter the input
#

putline() {
	line="${line%% }"
	echo "${line## }"
	line=""
}


line=""
#set -x
while read input
do
	# handle email headers 
	#
	if [ -n "$eflag" ]
	then
		case "$input" in
		Date:*)
			# remove the time
			echo "$input" | sed 's/[0-9][0-9]:..:[0-9][0-9].*//'
			continue
			;;
		Subject:*|From:*)
			echo "$input"
			continue
			;;
		esac
	fi
			
	# preserve blank lines
	#
	if [ -z "$input" ]
	then
		if [ -n "$line" ] 
		then
			#echo "$line"
			#line=""
			putline
		fi
		echo
		continue
	fi

	## 
	## For each space-separated word in $input ...
	##
	#eval set -- $(echo "$input" | sed 's/[^	 ][^	 ]*/"&"/g')
	set -f # no filename expansion
	set -- $input
	set +f
	for x
	do
		: x=":$x:"
		if [ "$period_space" == 1 ]
		then
			case "$x" in
			*.) x="$x " ;; ## extra space after period
			esac
		fi
		if (( ${#line}+${#x}>=n ))
		then
			putline
			line="$x"
		else
			line="$line $x"
			#echo "line:'$line'" >&2
		fi
	done
done
[ -n "$line" ] && putline

} ## end of filter