Improved and changed the make_buffer function.

It now returns the line as its first argument always, otherwise nil, errmsg

I updated scripts that use make_buffer.

When Lua 5.2 comes out, we may be able to use a function I've added
called stdnse.lines (commented for now). It cannot be used yet because
we cannot yield inside generic for loop. The function is built for
generic for loops. It will work as such:
for line in stdnse.lines(socket) do
  ...
end

nselib/stdnse.lua

@@ -4,6 +4,7 @@ local assert = assert;
 local tonumber = tonumber;
 local concat = table.concat;
 local nmap = require"nmap";
+local print = print
 
 module(... or "stdnse");
 
@@ -62,80 +63,44 @@ end
 --
 -- -Doug, June, 2007
 
---[[ function make_buffer(socket, sep)
-  local point, pattern, buffer = 1, "([^"..sep.."]-)"..sep.."?";
-  local function self(lines)
-    lines = lines or 1;
-    if not buffer then
-      local status, str = socket:receive_lines(lines);
+function make_buffer(socket, sep)
+  local point, left, buffer, done, msg = 1, "";
+  local function self()
+    if done then
+      return nil, msg; -- must be nil for stdnse.lines (below)
+    elseif not buffer then
+      local status, str = socket:receive_lines(1);
       if not status then
-        if buffer then
-          return buffer:sub(point);
+        if #left > 0 then
+          done, msg = not status, str;
+          return left;
         else
           return status, str;
         end
       else
-        buffer = str;
-        return self(lines);
+        buffer = left..str;
+        return self();
       end
     else
-      local _, j, str = buffer:find(pattern, point);
-      if j then
+      local i, j = buffer:find(sep, point);
+      if i then
+        local ret = buffer:sub(point, i-1);
         point = j + 1;
-        return str;
+        return ret;
       else
-        point, buffer = 1, nil;
-        return self(lines);
+        point, left, buffer = 1, buffer:sub(point), nil;
+        return self();
       end
     end
   end
   return self;
-end --]]
-
-make_buffer = function(sd, sep)
-  local self, result
-  local buf = ""
-
-  self = function()
-    local i, j, status, value
-
-    i, j = buf:find(sep)
-
-    if i then
-      if i == 1 then  -- empty line
-        buf = buf:sub(j+1, -1)
-        --return self() -- skip empty, tail
-        return true, "" -- return empty
-      else
-        value = buf:sub(1, i-1)
-        buf = buf:sub(j+1, -1)
-        return true, value
-      end
-    end
-
-    if result then
-      if #buf > 0 then  -- left over data with no terminating pattern
-        value = buf
-        buf = ""
-        return true, value
-      end
-      return nil, result
-    end
-
-    status, value = sd:receive()
-
-    if status then
-      buf = buf .. value
-    else
-      result = value
-    end
-
-    return self() -- tail
-  end
-
-  return self
 end
 
+--[[ This function may be usable in Lua 5.2
+function lines(socket)
+  return make_buffer(socket, "\r?\n"), nil, nil;
+end --]]
+
 do
   local t = {
     ["0"] = "0000",

scripts/ircServerInfo.nse

@@ -69,8 +69,6 @@ end
 
 
 action = function(host, port)
-  local status = 0
-  local line = ""
   local sd = nmap.new_socket()
   local curr_nick = random_nick()
   local sver, shost, susers, sservers, schans, sircops, slusers, slservers, sup, serr
@@ -121,8 +119,8 @@ action = function(host, port)
   buf = stdnse.make_buffer(sd, "\r?\n")
 
   while true do
-    status, line = buf()
-    if (not status) then break end
+    local line = buf()
+    if (not line) then break end
 
     -- This one lets us know we've connected, pre-PONGed, and got a NICK
     s, e, t = nmap.registry.ircserverinfo_375:exec(line, 0, 0)