diff --git a/.bin/lit.awk b/.bin/lit.awk
new file mode 100644
index 0000000..7346b37
--- /dev/null
+++ b/.bin/lit.awk
@@ -0,0 +1,17 @@
+BEGIN {
+  if (!comment) comment = "--";
+  if (!begin) begin = "\\begin{code}";
+  if (!end) end = "\\end{code}";
+}
+{
+  if ($0 == begin) {
+    code = 1;
+    print comment, $0;
+  } else if ($0 == end) {
+    code = 0;
+    print comment, $0;
+  } else {
+    if (code) print $0;
+    else print comment, $0;
+  }
+}