zfs-tests: verify zfs(8) and zpool(8) help message is under 80 columns

This commit updates the ZFS Test Suite to detect incorrect wrapping of
both zfs(8) and zpool(8) help message

Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #8785

tests/zfs-tests/tests/functional/cli_user/misc/zfs_001_neg.ksh

@@ -44,16 +44,20 @@
 
 function cleanup
 {
-	if [ -e $TEST_BASE_DIR/zfs_001_neg.$$.txt ]
+	if [ -e "$TEMPFILE" ]
 	then
-		rm $TEST_BASE_DIR/zfs_001_neg.$$.txt
+		rm -f "$TEMPFILE"
 	fi
 }
 
 log_onexit cleanup
 log_assert "zfs shows a usage message when run as a user"
 
-eval "zfs > $TEST_BASE_DIR/zfs_001_neg.$$.txt 2>&1"
-log_must grep "usage: zfs command args" $TEST_BASE_DIR/zfs_001_neg.$$.txt
+TEMPFILE="$TEST_BASE_DIR/zfs_001_neg.$$.txt"
+
+eval "zfs > $TEMPFILE 2>&1"
+log_must grep "usage: zfs command args" "$TEMPFILE"
+
+log_must eval "awk '{if (length(\$0) > 80) exit 1}' < $TEMPFILE"
 
 log_pass "zfs shows a usage message when run as a user"

tests/zfs-tests/tests/functional/cli_user/misc/zpool_001_neg.ksh

@@ -45,16 +45,20 @@
 
 function cleanup
 {
-	if [ -e $TEST_BASE_DIR/zpool_001_neg.$$.txt ]
+	if [ -e "$TEMPFILE" ]
 	then
-		rm $TEST_BASE_DIR/zpool_001_neg.$$.txt
+		rm -f "$TEMPFILE"
 	fi
 }
 
+TEMPFILE="$TEST_BASE_DIR/zpool_001_neg.$$.txt"
+
 log_onexit cleanup
 log_assert "zpool shows a usage message when run as a user"
 
-eval "zpool > $TEST_BASE_DIR/zpool_001_neg.$$.txt 2>&1"
-log_must grep "usage: zpool command args" $TEST_BASE_DIR/zpool_001_neg.$$.txt
+eval "zpool > $TEMPFILE 2>&1"
+log_must grep "usage: zpool command args" "$TEMPFILE"
+
+log_must eval "awk '{if (length(\$0) > 80) exit 1}' < $TEMPFILE"
 
 log_pass "zpool shows a usage message when run as a user"