--- /dev/null
+#!/bin/sh
+#
+# Usual approach to updating the expected outputs is
+# tests/filter/check
+# tests/filter/update-expected
+# selectively git-add the things that are right, after inspecting them
+
+set -e
+files=$(find tests/filter -name \*.tmp)
+for f in $files; do cp $f ${f%.tmp}.expected; done