zamfofex Comments - Deno

zamfofex

•Created by Asad on 3/19/2025 in #help

Deno permissions and security

I’m not sure if there is a way to set file descriptors other than 0,1,2 for child processes in Deno, but if that is possible, then that is a good alternative to hijacking the process’s std{in,out,err}.

29 replies

•Created by Asad on 3/19/2025 in #help

Deno permissions and security

But of course that means the subprocess won’t be able to use those streams as it normally would.

29 replies

•Created by Asad on 3/19/2025 in #help

Deno permissions and security

You can use stdin/stdout (and stderr) of the subprocess for communication.

29 replies

•Created by Asad on 3/19/2025 in #help

Deno permissions and security

The processes don’t have any constraints on what they can do, it’s the Deno runtime that can choose to allow/deny programs to exit the JS sandbox. In the case of workers, the runtime will allow the main thread to exit the sandbox, but deny the worker from doing so.

29 replies

•Created by iso on 3/15/2025 in #help

Deno env vars

Perhaps use import process from "node:process" then use process.env if it is running from a Node context.

10 replies

•Created by ruan on 3/12/2025 in #help

How to use cron?

I imagine they are asking if Deno Deploy only supports Deno.cron and not the package they brought up.

6 replies

•Created by Kay on 3/1/2024 in #help

Get image from automated download

See if this is satisfying enough! deno run -A cube.js

32 replies

•Created by Kay on 3/1/2024 in #help

Get image from automated download

If you just want an isometric image, you could create it without Three.js.

32 replies

•Created by Kay on 3/1/2024 in #help

Get image from automated download

I guess Three.js might not be possible, actually. 🤔

32 replies

•Created by Kay on 3/1/2024 in #help

Get image from automated download

But note that you can just run that code on Deno itself if you use the right tools, instead of having it run on a browser.

32 replies

•Created by Kay on 3/1/2024 in #help

Get image from automated download

I’m not sure you can easily/seamlessly just have Deno save the file from the browser JavaScript code.

32 replies

•Created by Kay on 3/1/2024 in #help

Get image from automated download

It seems like you’re actually downloading the page’s source instead of the image you want.

32 replies

•Created by Kay on 3/1/2024 in #help

Get image from automated download

marvinh’s code works for me. Are you sure the file being served is the same?

32 replies

•Created by spirobel on 2/25/2024 in #help

How to feed a ReadableStream / async Generator into a Response object?

If you want to be able to mix and match strings and buffers, you need a preprocessor function like this:

// mix strings and buffers

Deno.serve(request => new Response(ReadableStream.from(preprocess(request))))

let encoder = new TextEncoder()

async function * preprocess(request)
{
    for await (let chunk of makeStream(request))
    {
        if (typeof chunk === "string") chunk = encoder.encode(chunk)
        yield chunk
    }
}

async function * makeStream(request)
{
    yield "Hello, "
    yield encoder.encode("world!")
}

// mix strings and buffers

Deno.serve(request => new Response(ReadableStream.from(preprocess(request))))

let encoder = new TextEncoder()

async function * preprocess(request)
{
    for await (let chunk of makeStream(request))
    {
        if (typeof chunk === "string") chunk = encoder.encode(chunk)
        yield chunk
    }
}

async function * makeStream(request)
{
    yield "Hello, "
    yield encoder.encode("world!")
}

Otherwise, you can get away with only buffers or only strings more easily:

// only buffers
Deno.serve(request => new Response(ReadableStream.from(makeStream(request))))

let encoder = new TextEncoder()

async function * makeStream(request)
{
    yield encoder.encode("Hello, ")
    yield encoder.encode("world!")
}

// only buffers
Deno.serve(request => new Response(ReadableStream.from(makeStream(request))))

let encoder = new TextEncoder()

async function * makeStream(request)
{
    yield encoder.encode("Hello, ")
    yield encoder.encode("world!")
}

// only strings
Deno.serve(request => new Response(ReadableStream.from(makeStream(request)).pipeThrough(new TextEncoderStream())))

async function * makeStream(request)
{
    yield "Hello, "
    yield "world!"
}

// only strings
Deno.serve(request => new Response(ReadableStream.from(makeStream(request)).pipeThrough(new TextEncoderStream())))

async function * makeStream(request)
{
    yield "Hello, "
    yield "world!"
}

9 replies