#!/bin/ksh93

ETCMAIL='/etc/mail'
CFDIR='/usr/lib/mail'
M4=${M4:-/usr/bin/m4}
SCRIPT=${0##*/}
CFFILE=''

USAGE='[+NAME?'"${SCRIPT}"' - create a new sendmail configuration file using a m4 mail config file]'"
[+DESCRIPTION?A simple script to create a sendmail configuration file (*.cf) from a m4 mail config file (*.mc). It basically takes \afile\a\b.mc\b, generates a corresponding \afile\a\b.cf\b and symlinks it to \bsendmail.cf\b. If \afile\a\b.cf\b already exists, it gets copied to \afile\a\b.bak\b before the \bcf\b file gets overwritten.]
[+?Without any option, ${SCRIPT} creates a new \b${ETCMAIL}/client.cf\b from the file \b${ETCMAIL}/client.mc\b and symlinks it to \b${ETCMAIL}/sendmail.cf\b. This is a nullclient configuration file, which instructs sendmail to send all mails unmangled to the central mail gateway with the hostname \bmailhost\b.]
[h:help?Print this help and exit.]
[c:config]:[file?Use the given m4 \afile\a to create a new \b${ETCMAIL}/\b\afile\a\b.cf\b, which than gets symlinked to \b${ETCMAIL}/sendmail.cf\b.]
[s:server?Use the m4 file \b${ETCMAIL}/server.mc\b to create a new \b${ETCMAIL}/server.cf\b, which than gets symlinked to \b${ETCMAIL}/sendmail.cf\b. This is meant as an example, only. You should copy the \bserver.mc\b to another file (e.g. myserver.mc), adjust the settings and execute '\b${SCRIPT} -c myserver.mc\b'.]
[d:direct]:[dir?Create the \bcf\b file as well as the \bsendmail.cf\b symlink to it in the directory \adir\a instead of \b${ETCMAIL}/\b.]
[+NOTES?Since Solaris 10 it is possible to generate the sendmail server config file (per default \b/etc/mail/sendmail.cf\b) as well as the sendmail client config file (per default \b/etc/mail/submit.cf\b) on startup of the corresponding service automatically - see \bsendmail\b(4). So if you use this script without the option \b-d ...\b as well as the described mechanism, the generated \bcf\b file on startup may overwrite the \bcf\b file generated by this script!]
[+?Whenever a new \bcf\b file gets generated, the related sendmail service needs to be restarted to take the changes into account.]
[+SEE ALSO?\bsendmail\b(4), \bsvcadm\b(1M)]
"

if [[ ! -d ${ETCMAIL} ]]; then
	print -u2 "Mail configuration directory '$ETCMAIL' does not exist!"
	exit 1
fi
if [[ ! -d ${CFDIR} ]]; then
	print -u2 "Sendmail m4 config files directory '${CFDIR}' does not exist!"
	exit 2
fi

if [[ ! -x ${M4} ]]; then
	M4=${ whence m4 ; }
	[[ -z ${M4} ]] && M4=${ whence gm4 ; }
	if [[ -n ${M4} ]]; then
		print "Using ${M4} as macro processor."
	elif [[ -x /local/usr/bin/m4 ]]; then
		M4=/local/usr/bin/m4
	elif [[ -x /usr/local/bin/m4 ]]; then
		M4=/usr/local/bin/m4
	else
		print -u2 'Unable to find a usable m4 macro processor!'
		exit 3
	fi
fi
DESTDIR="${ETCMAIL}"

integer SERVER=0
while getopts -a ${SCRIPT} "${ print ${USAGE} ; }" OPT ; do
	case $OPT in
		s) SERVER=1 ;;
		c) CFFILE="${OPTARG}" ;;
		d) [[ ! -d ${OPTARG} ]] && \
				print -u2 "Directory '${OPTARG}' does not exists." && exit 7
			DESTDIR="${OPTARG}"
			;;
		h|*) $0 --man ; exit ;;
	esac
done
		

if [[ -z ${CFFILE} ]]; then
	CFFILE="${ETCMAIL}/"
	(( SERVER )) && CFFILE+=server.mc || CFFILE+=client.mc
else
	[[ ${F:0:1} != '/' ]] && CFFILE="${PWD}/${CFFILE}"
fi

if [[ ! -r ${CFFILE} ]]; then
	print -u2 "sendmail m4 config file '${CFFILE}' is not readable."
	exit 4
fi
print "Using '${CFFILE}' for configuration."

TARGET="${CFFILE##*/}"
TARGET="${TARGET%.*}'.cf'"

if [[ ${DESTDIR}/${TARGET} == ${CFFILE} ]]; then
	print -u2 '
  Please rename your configuration file to something else than
  '"${CFFILE}"' since we do not want to overwrite it.
  E.g.: '"${DESTDIR}/${TARGET}.mc"'
'
	exit 5
fi

"${M4}" -D_CF_DIR_=${CFDIR}/ ${CFDIR}/m4/cf.m4 "${CFFILE}" \
	>"${DESTDIR}/${TARGET}.tmp"

if (( $? )); then
	print -u2 '
Unable to produce '"${DESTDIR}/${TARGET}."'
'"${DESTDIR}/${TARGET}.tmp"' contains, what I got so far.
Delete it, if you do not need it for troubleshooting.'
	exit 6
fi

cd "${DESTDIR}"
[[ -e ${TARGET} ]] && mv "${TARGET}" "${TARGET}.bak"
mv "${TARGET}.tmp" "${TARGET}"
chmod 644 "${TARGET}"
rm -f sendmail.cf
ln -sf "./${TARGET}" sendmail.cf

print '
 Done.
 Check the new '"'${DESTDIR}/sendmail.cf'"' and restart sendmail, if it is ok.
'

if [[ -e ${TARGET}.bak ]]; then
	print '
 Otherwise cp the old '"'${DESTDIR}/${TARGET}.bak'"' back to '"'${DESTDIR}/sendmail.cf'"'.
'
fi