Generate id atteributes for headings

md2html

@@ -130,25 +130,20 @@ function inline(text) {
   next
 }
 
-/^# / {
+/^##* / {
+  d=length($1)
   gsub(/^#* /, "", $0)
-  if (!meta["title"]) meta["title"] = $0
+  if (d==1 && !meta["title"]) meta["title"] = $0
+  id1=$0
+  gsub(/[^a-zA-Z0-9]/, "", id1)
+  hash[d]=id1
+  id = ""
+  for (i = 2; i <= d; i++) {
+    id = id hash[i]
+  }
+  if (id != "") id = " id=\"" escape(id) "\""
   level(prefix)
-  oneliner("h1", $0)
-  next
-}
-
-/^## / {
-  gsub(/^#* /, "", $0)
-  level(prefix)
-  oneliner("h2", $0)
-  next
-}
-
-/^### / {
-  gsub(/^#* /, "", $0)
-  level(prefix)
-  oneliner("h3", $0)
+  oneliner("h"d, $0, id)
   next
 }