#!/usr/bin/ksh
usage () {
echo 'usage: mailx [-dv] [-F name] [-r from] [-s subject]
             <-t | [-b bcc] [-c cc] [to...]>
at least one of -t, -b, -c or to... must be specified.' >&2
	exit $1
}
sendmail='/usr/sbin/sendmail'
bcc= bccsep='BCC: '
cc= ccsep='CC: '
name= namesep='-F '
from= fromsep='-f '
subject='(no subject)' subjectsep='Subject: '
debug= toopt= verbose=
undisclosed='undisclosed-recipients:;'
while getopts 'b:c:dF:hr:s:tv' c; do
case ${c} in
'b')	bcc="${bcc}${bccsep}${OPTARG}"; bccsep=',' ;;
'c')	cc="${cc}${ccsep}${OPTARG}"; ccsep=',' ;;
'd')	debug='-d' ;;
'F')	name="${namesep}'${OPTARG}'" ;;
'h')	usage 0 ;;
'r')	from="${fromsep}'${OPTARG}'" ;;
's')	subject="${OPTARG}" ;;
't')	toopt='-t' ;;
'v')	verbose='-v' ;;
*)	usage 1 ;;
esac
done
shift $(($OPTIND-1))
nl='
'
toarg= to= tosep=
if [[ -n ${toopt} ]]; then
	cc= bcc=
else
	if [[ $# = 0 ]]; then
		if [[ -n ${cc}${bcc} ]]; then
			set -- "${undisclosed}"
		else
			usage 1
		fi
	else
		for arg; do toarg="${toarg}${tosep}'${arg}'"; tosep=' '; done
	fi
	tosep='To: '
	for arg; do to="${to}${tosep}${arg}"; tosep=','; done
	[[ -n ${to} ]] && to="${to}${nl}"
	[[ -n ${cc} ]] && cc="${cc}${nl}"
	[[ -n ${bcc} ]] && bcc="${bcc}${nl}"
fi
[[ -n ${subject} ]] && subject="${subjectsep}${subject}${nl}"
read -r line
nl1="${nl}"
nl2=
case ${line} in
*':'*)
	case ${line%%:*} in
	*' '*)
		;;
	*)
		nl1= nl2="${nl}"
		;;
	esac
	;;
'')
	nl1= nl2=
	;;
esac
if [[ -n ${debug} ]]; then
	sendmail=sendmail
	sendmail () { echo sendmail "$@"; cat; }
fi
eval ${sendmail} ${toopt} ${verbose} ${name} ${from} ${toarg} << EOF
${subject}${to}${cc}${bcc}${nl1}${line}${nl2}$(cat)
EOF
#!eof