Lua

Download a Binary File into Memory

See more Azure Cloud Storage Examples

Downloads a binary file into memory. Lua

local chilkat = require("chilkat")

-- Azure File Service Example: Download a Binary File to Memory
-- See:  https://docs.microsoft.com/en-us/rest/api/storageservices/get-file

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local rest = chilkat.Rest.new()

-- Connect to the Azure Storage Blob Service
local bTls = true
local port = 443
local bAutoReconnect = true
-- In this example, the storage account name is "chilkat".
local success = rest:connect("chilkat.file.core.windows.net", port, bTls, bAutoReconnect)
if not success then
    print(rest.last_error_text)
    return
end

-- Provide Azure Cloud credentials for the REST calls.
local azAuth = chilkat.AuthAzureStorage.new()
azAuth.access_key = "AZURE_ACCESS_KEY"
-- The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.account = "chilkat"
azAuth.scheme = "SharedKey"
azAuth.service = "File"
-- This causes the "x-ms-version: 2021-08-06" header to be automatically added.
azAuth.xms_version = "2021-08-06"
success = rest:set_auth_azure_storage(azAuth)

-- Note: The application does not need to explicitly set the following
-- headers: x-ms-date, Authorization.  These headers
-- are automatically set by Chilkat.

-- Send a GET request to download the file "penguins.jpg" to a BinData object.
-- (The share name is "pip")
local bdFileContents = chilkat.BinData.new()
success = rest:full_request_no_body_bd("GET", "/pip/wildlife/antarctic/penguins.jpg", bdFileContents)
if not success then
    print(rest.last_error_text)
    return
end

-- When successful, the response status will be 200.
-- If a non-success status code is returned, then the bdFileContents actually contains the XML error message.
if rest.response_status_code ~= 200 then
    -- Examine the request/response to see what happened.
    print("response status code = " .. rest.response_status_code)
    print("response status text = " .. rest.response_status_text)
    print("response header: " .. rest.response_header)
    local sbXmlErr = chilkat.StringBuilder.new()
    sbXmlErr:append_bd(bdFileContents, "utf-8", 0, 0)
    print("response body (if any): " .. sbXmlErr:get_as_string())
    print("---")
    print("LastRequestStartLine: " .. rest.last_request_start_line)
    print("LastRequestHeader: " .. rest.last_request_header)
    return
end

print("Size of the downloaded file = " .. bdFileContents.num_bytes)

-- See the online reference documentation for the BinData class for ways
-- to access the bytes.

bdFileContents:write_file("qa_output/penguins.jpg")