Read from a resource ID (rid) into an array buffer (buffer).

Resolves to either the number of bytes read during the operation or EOF (null) if there was nothing more to read.

It is possible for a read to successfully return with 0 bytes. This does not indicate EOF.

This function is one of the lowest level APIs and most users should not work with this directly, but rather use readAll() from std/streams/conversion.ts instead.

It is not guaranteed that the full buffer will be read in a single call.

// if "/foo/bar.txt" contains the text "hello world":
const file = await Deno.open("/foo/bar.txt");
const buf = new Uint8Array(100);
const numberOfBytesRead = await Deno.read(file.rid, buf); // 11 bytes
const text = new TextDecoder().decode(buf);  // "hello world"
Deno.close(file.rid);