---
-- cURL bindings. read the cURL curl_easy_setopt manpage.
-- As a convention all CURL_XXXXX and CURLXXXXX names are mapped to curl.XXXXX
-- constants. options taking a long now take a number, options taking a string 
-- here take a string (no need to ensure the string will be available until
-- you call perform, the bindings do this for you). Functions to write like the
-- curl.OPT_WRITEFUNCTION and curl.OPT_HEADERFUNCTION take a string argument and
-- a number (the string len) must return a couple, byte,server and error message-- . if the number of byte returned is different from the string len it is 
-- considered an error. this is an example of a callback factory: <br>
-- <pre style="color:blue;">
-- function build_w_cb(t)
--         return function(s,len)
--                   <i>stores the received data in the table t</i>
--                 table.insert(t,s)
--                   <i>return number_of_byte_served, error_message</i>
--                   <i>number_of_byte_served ~= len is an error</i>
--                 return len,nil
--         end
-- end
-- </pre>
-- This cb factory stores all the chunks received in table t. you can have the
-- whole file back using table.concat(t). The callback for 
-- curl.OPT_READFUNCTION takes a number, the number of the maximum amount of 
-- data that can return. Here a simple example of an infinite stream of '#':<br>
-- <pre style="color:blue;">
-- function build_r_cb()
--      return function(n)
--              local s = string.rep("#",n)
--                <i>return size_of_data,data</i>
--                <i>size_of_data = 0 means end of data</i>
--                <i>size_of_data must be <= n</i>
--              return string.len(s),s
--      end
--end
-- </pre>
-- curl_slist are mapped to lua tables {"item1","item2",...}. For example
-- curl.OPT_HTTPHEADER may be called in this way:<br>
-- <pre style="color:blue;">
-- c:setopt(curl.OPT_HTTPHEADER,{"Referer: my_home!","Dummy-field: hello"})
-- </pre>
-- Last important case is the curl.OPT_HTTPPOST for which a special syntax is 
-- supported:
-- <pre style="color:blue;">
-- c:setopt(curl.OPT_HTTPPOST,{
--
--      {curl.FORM_COPYNAME,"name1",
--       curl.FORM_COPYCONTENTS,"data1",
--       curl.FORM_CONTENTTYPE,"Content-type: text/plain",
--       curl.FORM_END }
--      ,
--      {curl.FORM_COPYNAME,"name2",
--       curl.FORM_COPYCONTENTS,"data2",
--       curl.FORM_CONTENTTYPE,"Content-type: text/plain",
--       curl.FORM_END}
-- })
-- </pre>
-- And now a simple example of an HTTP GET with a proxy:<br>
-- <pre style="color:blue;">
--gl_b = {}
--gl_h = {}
--
--c = curl.easy_init() 
--c:setopt(curl.OPT_URL,'http://tassi.web.cs.unibo.it/cgi-bin/stats.cgi')
--c:setopt(curl.OPT_WRITEFUNCTION,build_w_cb(gl_b))
--c:setopt(curl.OPT_HEADERFUNCTION,build_w_cb(gl_h))
--c:setopt(curl.OPT_PROXY,"localhost:3000")
--c:setopt(curl.OPT_PROXYUSERPWD,"ciccio:ciccio")
--print("\n\t$$ performing... returns code,error $$\n")
--print(c:perform())
--print("\n\t$$ here you see the header, line per line $$\n")
--table.foreach(gl_h,function(i,s) print(i.."= "..string.gsub(s,"\n","")) end)
--print("\n\t$$ and here you see the data, after concatenation of "..
--      table.getn(gl_b).." chunks $$\n")
--print(table.concat(gl_b))
--</pre>

---
-- Create a curl handler.
-- @return userdata The CURL* handler object.
function curl.easy_init() end

---
-- The setopt function.
-- @param opt number one of curl.OPT_*.
function setopt(opt,data) end

---
-- Starts curl.
-- @return number,errorstring number not zero means an error.
function perform() end
		
---
-- URLencodes the string.
-- @return string The escaped string.
function curl.escape(s) end

---
-- URLdecodes the string.
-- @return string The unescaped string.
function curl.unescape(s) end

---
-- version.
-- @return string The version string.
function curl.version() end

---
-- version informations.
-- @return table The version struct.
function curl.version_info() end