Stuart Henderson <stu@spacehopper.org> writes:

>> > I'd recommend no new version -> no output (like syspatch -c does),
>> > so it can be used in cron without an extra | grep -v.
>> 
>> Ok but then I think I should also tame the verbosity of ftp when using
>> this flag, no?
>
> yes.

What about this?

Index: sysupgrade.8
===================================================================
RCS file: /cvs/src/usr.sbin/sysupgrade/sysupgrade.8,v
diff -u -p -r1.23 sysupgrade.8
--- sysupgrade.8	11 Nov 2025 15:18:30 -0000	1.23
+++ sysupgrade.8	3 Jul 2026 16:01:21 -0000
@@ -22,7 +22,7 @@
 .Nd upgrade system to the next release or a new snapshot
 .Sh SYNOPSIS
 .Nm
-.Op Fl fkns
+.Op Fl cfkns
 .Op Fl b Ar base-directory
 .Op Fl R Ar version
 .Op Ar installurl | path
@@ -54,6 +54,9 @@ Download files to
 .Ar base-directory Ns / Ns Pa _sysupgrade
 instead of
 .Pa /home/_sysupgrade .
+.It Fl c
+Print availability of a new version.
+The sets are not downloaded.
 .It Fl f
 For snapshots, force an already applied upgrade.
 This option has no effect on releases.
Index: sysupgrade.sh
===================================================================
RCS file: /cvs/src/usr.sbin/sysupgrade/sysupgrade.sh,v
diff -u -p -r1.62 sysupgrade.sh
--- sysupgrade.sh	21 Mar 2026 01:34:25 -0000	1.62
+++ sysupgrade.sh	3 Jul 2026 16:01:21 -0000
@@ -74,6 +74,7 @@ rmel() {
 
 SNAP=false
 FILE=false
+CHECK=false
 FORCE=false
 FORCE_VERSION=false
 KEEP=false
@@ -83,9 +84,10 @@ WHAT='release'
 VERSION=$(uname -r)
 NEXT_VERSION=$(echo ${VERSION} + 0.1 | bc)
 
-while getopts b:fknrR:s arg; do
+while getopts b:cfknrR:s arg; do
 	case ${arg} in
 	b)	SETSDIR=${OPTARG}/_sysupgrade;;
+	c)	CHECK=true;;
 	f)	FORCE=true;;
 	k)	KEEP=true;;
 	n)	REBOOT=false;;
@@ -140,11 +142,18 @@ fi
 install -d -o 0 -g 0 -m 0755 ${SETSDIR}
 cd ${SETSDIR}
 
-echo "Fetching from ${URL}"
-if ! unpriv -f SHA256.sig ftp -N sysupgrade -Vmo SHA256.sig ${URL}SHA256.sig; then
+# Reduce verbosity when we're just checking for a new version.
+if $CHECK; then
+    ftpflags="-N sysupgrade -V"
+else
+    ftpflags="-N sysupgrade -Vm"
+fi
+
+$CHECK || echo "Fetching from ${URL}"
+if ! unpriv -f SHA256.sig ftp $ftpflags -o SHA256.sig ${URL}SHA256.sig; then
 	if [[ -n ${ALT_URL} ]]; then
-		echo "Fetching from ${ALT_URL}"
-		unpriv -f SHA256.sig ftp -N sysupgrade -Vmo SHA256.sig ${ALT_URL}SHA256.sig
+		$CHECK || echo "Fetching from ${ALT_URL}"
+		unpriv -f SHA256.sig ftp $ftpflags -o SHA256.sig ${ALT_URL}SHA256.sig
 		URL=${ALT_URL}
 		NEXT_VERSION=${VERSION}
 	else
@@ -166,30 +175,38 @@ if ! [[ -r /etc/signify/$KEY ]]; then
 	    tail -2 | head -1 | cut -d- -f2)
 	BUNDLE=sigbundle-${HAVEKEY}.tgz
 	FWKEY=$(echo $KEY | sed -e 's/base/fw/')
-	echo "Adding missing keys from bundle $BUNDLE"
-	unpriv -f ${BUNDLE} ftp -N sysupgrade -Vmo $BUNDLE https://ftp.openbsd.org/pub/OpenBSD/signify/$BUNDLE
+	$CHECK || echo "Adding missing keys from bundle $BUNDLE"
+	unpriv -f ${BUNDLE} ftp $ftpflags -o $BUNDLE https://ftp.openbsd.org/pub/OpenBSD/signify/$BUNDLE
 	signify -Vzq -m - -x $BUNDLE | (cd /etc/signify && tar xfz - $KEY $FWKEY)
 	rm $BUNDLE
 fi
 
-unpriv -f SHA256 signify -Ve -x SHA256.sig -m SHA256
+unpriv -f SHA256 signify -Ve ${CHECK:+-q} -x SHA256.sig -m SHA256
 rm SHA256.sig
 
-if cmp -s /var/db/installed.SHA256 SHA256 && ! $FORCE; then
+if cmp -s /var/db/installed.SHA256 SHA256 && ! $FORCE && ! $CHECK; then
 	echo "Already on latest ${WHAT}."
 	exit 0
 fi
 
-unpriv -f BUILDINFO ftp -N sysupgrade -Vmo BUILDINFO ${URL}BUILDINFO
+unpriv -f BUILDINFO ftp $ftpflags -o BUILDINFO ${URL}BUILDINFO
 unpriv cksum -qC SHA256 BUILDINFO
 
 if [[ -e /var/db/installed.BUILDINFO ]]; then
 	installed_build_ts=$(cut -f3 -d' ' /var/db/installed.BUILDINFO)
 	build_ts=$(cut -f3 -d' ' BUILDINFO)
-	if (( $build_ts <= $installed_build_ts )) && ! $FORCE; then
+	if $CHECK; then
+	    build_human_ts=$(cut -f5- -d' ' BUILDINFO)
+	    if (( $build_ts > $installed_build_ts )); then
+		echo "A new version ($build_human_ts) is available."
+	    fi
+	    exit 0
+	elif (( $build_ts <= $installed_build_ts )) && ! $FORCE; then
 		echo "Downloaded ${WHAT} is older than installed system. Use -f to force downgrade."
 		exit 1
 	fi
+elif $CHECK; then
+    err "Cannot find installed version."
 fi
 
 # INSTALL.*, bsd*, *.tgz
@@ -210,7 +227,7 @@ done
 
 [[ -n ${OLD_FILES} ]] && rm ${OLD_FILES}
 for f in ${DL}; do
-	unpriv -f $f ftp -N sysupgrade -Vmo ${f} ${URL}${f}
+	unpriv -f $f ftp $ftpflags -o ${f} ${URL}${f}
 done
 
 if [[ -n ${DL} ]]; then

-- 
Manuel Giraud