Add. Mime HTTP example.

Author: moteus

examples/cURLv3/post_mime.lua

@@ -0,0 +1,56 @@
+local curl = require "cURL"
+
+local null = curl.null
+
+-- make first request
+
+-- Documentation does not restrict use same mime with different easy handle.
+-- In fact it does not mention this case at all. But in my experiments it works.
+local easy = curl.easy()
+
+-- Create new mime object.
+-- cURL documentation doesn not mentioned that
+-- this mime object can be used only 
+local mime = easy:mime()
+
+-- Add part. Source of data is file on disk.
+-- If file not exists then perform returns `[CURL-EASY][READ_ERROR]` error
+-- There no way to remove existed part from mime.
+local part = mime:addpart{
+  filedata = './post_mime.lua',
+  type     = 'application/lua',
+  filename = 'post_mime.lua',
+  encoder  = 'base64',
+}
+
+local buffer = {}
+
+-- Use mime object as request body
+easy:setopt{
+  url      = 'http://127.0.0.1:7090/post',
+  mimepost = mime,
+}
+
+easy:setopt_writefunction(table.insert, buffer)
+
+local ok, err = easy:perform()
+if ok then
+  local code, url, content =  easy:getinfo_effective_url(),
+      easy:getinfo_response_code(), table.concat(buffer)
+  print(code, url)
+  print(content)
+else
+  print(err)
+end
+
+easy:close()
+
+-- E.g. it does not send filedata second time.
+-- Lua-cURL does not free mime when close `parent` easy.
+
+-- Explicitly free mime object and all its parts
+-- There no way to reuse only some parts.
+mime:free()
+
+-- Subparts become also freed
+print(part)