Hosts.hs tweaks

1 files changed, 43 insertions, 3 deletions

diff --git a/Hosts.hs b/Hosts.hs
index 5b117c7..29e54be 100644
--- a/Hosts.hs
+++ b/Hosts.hs
@@ -130,7 +130,7 @@ scrubName f line = line'
     (a,ws') = splitAt 2 ws
     ws'' = f ws'
     line' = if null ws'' 
-                then if length a==2 then "# " <> L.concat a <> ign
+                then if length a==2 then "" -- "# " <> L.concat a <> ign
                                     else line
                 else if length a==2 
                     then L.concat (a ++ ws'') <> ign
@@ -147,6 +147,36 @@ scrubName f line = line'
 assignName :: SockAddr -> L.ByteString -> Hosts -> Hosts
 assignName addr name hosts = assignName0 False addr name hosts
 
+chaddr :: Int -> SockAddr -> Hosts -> Hosts
+chaddr n addr hosts =
+    hosts { addrnum = Map.insert addr n (addrnum hosts)
+          , numline = Map.adjust re n (numline hosts) }
+ where
+    re line = if length a==2
+                then L.pack (inet_ntop addr) <> " " <> L.concat ws' <> ign
+                else line
+        where (x,ign) = L.break (=='#') line
+              ws  = L.groupBy ( (==EQ) `oo` comparing isSpace) x
+                                  where oo = (.) . (.)
+              (a,ws') = splitAt 2 ws
+
+isLonerName line = length ws' <= 2
+        where (x,_) = L.break (=='#') line
+              ws  = L.groupBy ( (==EQ) `oo` comparing isSpace) x
+                                  where oo = (.) . (.)
+              (_,ws') = splitAt 2 ws
+
+scrubTrailingEmpties :: Hosts -> Hosts
+scrubTrailingEmpties hosts =
+    hosts { lineCount = cnt'
+          , numline = foldl' (flip Map.delete) (numline hosts) es
+          }
+ where
+    cnt = lineCount hosts
+    es = takeWhile (\n -> Map.lookup n (numline hosts) == Just "")
+            $ [cnt,cnt-1..]
+    cnt' = cnt - length es
+
 assignName0 :: Bool -> SockAddr -> L.ByteString -> Hosts -> Hosts
 assignName0 iscannon addr name hosts = hosts'
  where
@@ -157,9 +187,19 @@ assignName0 iscannon addr name hosts = hosts'
          then hosts -- address already has name, nothing to do
          else 
             let hosts0 = -- remove name if it's present
-                         maybe hosts (removeName hosts) ns
+                         scrubTrailingEmpties $ maybe hosts (removeName hosts) ns
+                ns' = fmap (filter $
+                                isLonerName
+                                . fromJust
+                                . (\n -> Map.lookup n (numline hosts)))
+                            ns
+                        >>= listToMaybe
                 hosts1 = -- insert name, or add new line
-                         maybe (newLine hosts0) (appendName iscannon name hosts0) a
+                         maybe (maybe (newLine hosts0)
+                                      (\n -> chaddr n addr $ appendName iscannon name hosts0 n)
+                                      ns')
+                               (appendName iscannon name hosts0)
+                               a
             in hosts1
     removeName hosts nums = hosts 
         { namenum = Map.delete name (namenum hosts)