Converting UnsafePointers to string

[targetlucked69]

Hello, playing round the unstable Deno FFI and so far loving it. One question tho

Suppose I have this

const sys = Deno.dlopen(lib, {
  func: {
    name: 'some_func',
    parameters: ['pointer'], 
    result: 'pointer' 
  },
});

sys.symbols.func() // returns UnsafePointer { value: 105553155269408n }

Is there a method we can use to convert the pointer to a string for example? Thanks!

[melkir]

Hello @walmartwarlord,
You might want to take a look at these resources, especially the getCString method.
https://deno.com/blog/v1.17#updates-to-the-ffi-api
https://doc.deno.land/deno/unstable/~/Deno.UnsafePointer
https://doc.deno.land/deno/unstable/~/Deno.UnsafePointerView

From what I understand, you have to create a buffer to store the value. On top of that you add a pointer, and the view part allows you to retrieve the value.

Edit: You can also use rust code to write your function + deno_bindgen to automatically generate the Typescript equivalent. It's a slightly different approach, but it helps to understand how it works under the hood.

[targetlucked69]

Thank you for the resource.

I've been looking at how deno_bindgen returns structs and arrays and based on the examples it looks like Rust returns stringified objects/arrays so that Deno can just JSON.parse it?