curl POST to gitlab snippets api

gitlab_curl_post

$ cat > content.py
# -*- coding: utf-8 -*-
# 日本語
# あめんぼあかいなあいうえお
def hello():
  print "hello world!"

if __name__ == "__main__":
  hello()
^D

$ curl.exe -F "title=test1" -F "file_name=content1.py" -F "code=<content.py" http://demo.gitlabhq.com/api/v2/projects/rubinius/snippets?private_token=qp6szjqmk8bTyMBrnJo5

これもOKだった。
curl.exe -d '{"private_token":"qp6szjqmk8bTyMBrnJo5","title":"test1","file_name":"content1.py","code":"hogehoge\nhoge"}' http://demo.gitlabhq.com/api/v2/projects/rubinius/snippets

これはだめだった。違いがわからない。
echo '{"private_token":"qp6szjqmk8bTyMBrnJo5","title":"test1","file_name":"content1.py","code":"hogehoge\nhoge"}' > content.json
curl.exe -d '@content.json' http://demo.gitlabhq.com/api/v2/projects/rubinius/snippets

gg

curl.exe -d '{"private_token":"qp6szjqmk8bTyMBrnJo5","title":"test1","file_name":"content1.py","code":"hogehoge\nhoge"}' http://demo.gitlabhq.com/api/v2/projects/rubinius/snippets