#!/bin/bash

mailfile=${MAIL:-/var/spool/mail/$LOGNAME}

getusername () {
	awk -F : '{if ($1 == ENVIRON["LOGNAME"])
			{sub (/,.*/, "", $5); print $5; }}' /etc/passwd
}
[ "$MAILNAME" ] || MAILNAME=$(getusername)
export MAILNAME

newmail () {
cat $mailfile | formail -c -X From: -X Subject: -X To: -s awk '
/From: .* <.*@.*>/	{ sub(/ <.*/, ""); FROM = substr($0, 7); next }
/From: .*@.* <.*>/	{ sub(/.*</, ""); sub(/>.*/, ""); FROM = $0; next }
/From: /		{ FROM = substr($0, 7); next }
/To: .* <.*@.*>/	{ sub(/ <.*/, ""); TO = substr($0, 5); next }
/To: .*@.* <.*>/	{ sub(/.*</, ""); sub(/>.*/, ""); TO = $0; next }
/To: /			{ TO = substr($0, 5); next }
/Subject: /		{ SUBJECT = substr($0, 10) }
END			{
				sub(/^"/, "", FROM); sub(/"$/, "", FROM);
				sub(/^</, "", FROM); sub(/>$/, "", FROM);
				if (FROM == ENVIRON["MAILNAME"]) {
					sub(/^"/, "", TO); sub(/"$/, "", TO);
					sub(/^</, "", TO); sub(/>$/, "", TO);
					FROM = sprintf("To %s", TO);
				}
				sub(/^ */, "", FROM); sub(/ *$/, "", FROM);
				sub(/^ */, "", SUBJECT);sub(/ *$/, "", SUBJECT);
				printf "%-16.16s: %s\n", FROM, SUBJECT;
			}' 
}

usage () {
cat <<EOF 1>&2
Usage: $0 [-h] [-q] [-t] [-f filename]
	Display all mail message senders and subjects.
	-h -- generate this help listing
	-q -- generate no output, just a return value
	-t -- just indicate "You have mail" if appropriate, but no details
	-f -- indicate a mail file other than ${MAIL:-/var/spool/mail/$LOGNAME}

	Environment: MAILNAME is used to determine determine mail from you.
		     If not set, the name field from /etc/passwd is used.

		     If set, MAIL contains the default mailbox, if not
		     /var/spool/mail/LOGNAME is used.

	Exit codes: 0 -- mail present, 1 -- no mail, 2 -- bad arguments
EOF
}

TEST=false
QUIET=false

while getopts "f:hqt" arg
do
	case $arg in
	f)	mailfile=$OPTARG ;;
	q)	QUIET=true ;;
	t)	TEST=true ;;
	h)	usage ; exit 2 ;;
	?)	usage ; exit 2 ;;
	esac
done

NEWMAIL=false
newmail | grep -q . && NEWMAIL=true

if ! $QUIET
then
	if $NEWMAIL
	then
		if $TEST
		then
			echo "You have mail"
		else
			newmail
		fi
	fi
fi

$NEWMAIL