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  • Ruby

Idiom #102 Load from HTTP GET request into a file

Make an HTTP request with method GET to the URL u, then store the body of the response in the file result.txt. Try to save the data as it arrives if possible, without having all its content in memory at once.

require 'net/http'
u = URI('http://example.com/large_file')

Net::HTTP.start(u.host, u.port) do |http|
  request = Net::HTTP::Get.new(u)
  http.request(request) do |response|
    open('result.txt', 'w') do |file|
      response.read_body do |chunk|
        file.write(chunk)
      end
    end
  end
end

The body is passed to the block, provided in fragments, as it is read in from the socket.
require 'open-uri'
response = URI.open(u).read
File.write("result.txt", response)
import std.net.curl;
download(u, "result.txt");
New implementation...
< > ⌨
programming-idioms.org 
u = URI('http://example.com/large_file')

Net::HTTP.start(u.host, u.port) do |http|
  request = Net::HTTP::Get.new(u)
  http.request(request) do |response|
    open('result.txt', 'w') do |file|
      response.read_body do |chunk|
        file.write(chunk)
      end
    end
  end
end
response = URI.open(u).read
File.write("result.txt", response)
download(u, "result.txt");
out, err := os.Create("result.txt")
if err != nil {
	return err
}
defer out.Close()

resp, err := http.Get(u)
if err != nil {
	return err
}
defer func() {
	io.Copy(io.Discard, resp.Body)
	resp.Body.Close()
}()
if resp.StatusCode != 200 {
	return fmt.Errorf("Status: %v", resp.Status)
}

_, err = io.Copy(out, resp.Body)
if err != nil {
	return err
}
(serapeum:write-stream-into-file
   (dex:get u :want-stream t)
              #P"result.txt"
              :direction :output
              :if-exists :supersede
              :if-does-not-exist :create)
var
  str: TMemorystream;
begin
  with TFPHTTPClient.create(nil) do 
  try
    str := TMemoryStream.create;
    try
      get(u, str);
      str.saveToFile('result.txt');
    finally
      str.free;
    end;
  finally
    free;
  end;
end;
my $response = HTTP::Tiny->new->mirror($u, 'result.txt');
filename, headers = urllib.request.urlretrieve(u, 'result.txt')

with open("results.txt", "wb") as fh:
	fh.write(requests.get(u).content)
let client = Client::new();
match client.get(&u).send() {
    Ok(res) => {
        let file = File::create("result.txt")?;
        ::std::io::copy(res, file)?;
    },
    Err(e) => eprintln!("failed to send request: {}", e),
};