local mongo = require('mongo')
-- Create a connection object
local db = assert(mongo.Connection.New())
-- connect to the server on localhost
assert(db:connect('localhost'))
-- create a GridFS handle
local gridfs = assert(mongo.GridFS.New(db, 'test'))
-- store a file on the server
local gridfile = assert(gridfs:store_file('/path/to/file'))
-- print details
print(gridfile:num_chunks())
print(gridfile:chunk_size())
print(gridfile:md5())
print(gridfile:metadata())
print(gridfile:upload_date())
print(#gridfile) -- synonym for gridfile:content_length()
-- examine file chunks
local chunk = assert(gridfile:chunk(0))
print(#chunk) -- synonym for chunk:len()
print(chunk:data())
-- write file data
assert(gridfile:write('/path/to/newfile'))
-- list files on the DB
local q = gridfs:list()
for gf in q:results() do
    print(gf:field('filename'))
end