diff --git a/tools/linechk b/tools/linechk
new file mode 100755
index 0000000..aeaae52
--- /dev/null
+++ b/tools/linechk
@@ -0,0 +1,42 @@
+#!/bin/sh
+#
+# Code quality tool; check line length of each file in certain directories
+#
+# For a list of ignored patterns, see chk-linelen-ignores
+#
+#   Copyright (C) 2012  Mike Gerwitz
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+##
+
+root="${1:-.}"
+
+hideignores()
+{
+  grep -v "$(
+    sed '/^#/d;
+      s/\n/|/g;
+      s/|$//;
+    ' "$root/tools/linechk-ignores"
+  )"
+}
+
+# output all file with lines > 80 characters and exit successfully if grep has a
+# non-zero status code, indicating that no matches were found
+cd "$root" && \
+  find lib/ tools/ test/ doc/ README* LICENSE Makefile *.js \
+    -type f -exec wc -L {} \; \
+      | hideignores \
+      | grep -v '^\([0-7][0-9]\?\|80\?\) ' \
+      || exit 0
diff --git a/tools/linechk-ignores b/tools/linechk-ignores
new file mode 100644
index 0000000..fe18a09
--- /dev/null
+++ b/tools/linechk-ignores
@@ -0,0 +1,6 @@
+# any file matching any pattern in this file is ignored by the line check tool
+# (uses POSIX regular expressions, as is default in grep)
+doc/highlight.pack.js$
+.png$
+.dia$
+.jar$