sample/libcurl: add body and writ_data function/callbacks

samples/libcurl/src/main/kotlin/org/konan/libcurl/CUrl.kt

@@ -14,10 +14,13 @@ class CUrl(val url: String)  {
         val header = staticCFunction(::header_callback)
         curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header)
         curl_easy_setopt(curl, CURLOPT_HEADERDATA, stableRef.asCPointer())
+        val write_data = staticCFunction(::write_callback)
+        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data)
+        curl_easy_setopt(curl, CURLOPT_WRITEDATA, stableRef.asCPointer())
     }
 
     val header = Event<String>()
-    val data = Event<String>()
+    val body = Event<String>()
 
     fun nobody(){
         curl_easy_setopt(curl, CURLOPT_NOBODY, 1L)
@@ -50,13 +53,14 @@ fun header_callback(buffer: CPointer<ByteVar>?, size: size_t, nitems: size_t, us
     return size * nitems
 }
 
-/*
+
-fun write_callback(buffer: COpaquePointer?, size: size_t, nitems: size_t, userdata: COpaquePointer?): size_t {
+fun write_callback(buffer: CPointer<ByteVar>?, size: size_t, nitems: size_t, userdata: COpaquePointer?): size_t {
     if (buffer == null) return 0
+    val data = buffer.toKString((size * nitems).toInt()).trim()
     if (userdata != null) {
         val curl = userdata.asStableRef<CUrl>().get()
-        curl.data(buffer.)
+        curl.body(data)
     }
     return size * nitems
 }
-*/
+

samples/libcurl/src/main/kotlin/org/konan/libcurl/Program.kt

@@ -8,13 +8,15 @@ fun main(args: Array<String>) {
     curl.header += {
         println("[H] $it")
     }
+
+    curl.body += {
+        println("[B] $it")
+    }
+
     curl.fetch()
     curl.close()
 
-/*
+
-    val write_data = staticCFunction(::write_data)
-    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
-*/
 }
 
 fun help() {