diff -ruN a/regress/cipher-speed.sh b/regress/cipher-speed.sh
--- a/regress/cipher-speed.sh	2019-12-03 13:16:36.091896387 -0600
+++ b/regress/cipher-speed.sh	2019-12-03 13:28:29.726275955 -0600
@@ -17,7 +17,7 @@
 		printf "%-60s" "$c/$m:"
 		( ${SSH} -o 'compression no' \
 			-F $OBJ/ssh_proxy -m $m -c $c somehost \
-			exec sh -c \'"dd of=/dev/null obs=32k"\' \
+			exec sh -c \'"dd of=/dev/null bs=32k"\' \
 		< ${DATA} ) 2>&1 | getbytes
 
 		if [ $? -ne 0 ]; then
diff -ruN a/regress/key-options.sh b/regress/key-options.sh
--- a/regress/key-options.sh	2019-12-03 13:24:44.164243780 -0600
+++ b/regress/key-options.sh	2019-12-03 13:33:14.447235791 -0600
@@ -84,7 +84,7 @@
 	fi
 
 	sed 's/.*/from="'"$f"'" &/' $origkeys >$authkeys
-	from=`head -1 $authkeys | cut -f1 -d ' '`
+	from=`head -n 1 $authkeys | cut -f1 -d ' '`
 	verbose "key option $from"
 	r=`${SSH} -q -F $OBJ/ssh_proxy somehost 'echo true'`
 	if [ "$r" = "true" ]; then
diff -ruN a/regress/transfer.sh b/regress/transfer.sh
--- a/regress/transfer.sh	2019-12-03 13:16:58.342857354 -0600
+++ b/regress/transfer.sh	2019-12-03 13:29:08.733267753 -0600
@@ -13,7 +13,7 @@
 for s in 10 100 1k 32k 64k 128k 256k; do
 	trace "dd-size ${s}"
 	rm -f ${COPY}
-	dd if=$DATA obs=${s} 2> /dev/null | \
+	dd if=$DATA bs=${s} 2> /dev/null | \
 		${SSH} -q -F $OBJ/ssh_proxy somehost "cat > ${COPY}"
 	if [ $? -ne 0 ]; then
 		fail "ssh cat $DATA failed"
diff -ruN a/regress/yes-head.sh b/regress/yes-head.sh
--- a/regress/yes-head.sh	2019-12-03 13:17:11.682259074 -0600
+++ b/regress/yes-head.sh	2019-12-03 13:32:47.699869866 -0600
@@ -3,7 +3,7 @@
 
 tid="yes pipe head"
 
-lines=`${SSH} -F $OBJ/ssh_proxy thishost 'sh -c "while true;do echo yes;done | _POSIX2_VERSION=199209 head -2000"' | (sleep 3 ; wc -l)`
+lines=`${SSH} -F $OBJ/ssh_proxy thishost 'sh -c "while true;do echo yes;done | _POSIX2_VERSION=199209 head -n 2000"' | (sleep 3 ; wc -l)`
 if [ $? -ne 0 ]; then
 	fail "yes|head test failed"
 	lines = 0;