method Deno.FsFile.prototype.readSync
FsFile.prototype.readSync(p: Uint8Array): number | null
Synchronously read from the file into an array buffer (`p`).
Returns 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.
**It is not guaranteed that the full buffer will be read in a single
call.**
```ts
// if "/foo/bar.txt" contains the text "hello world":
using file = Deno.openSync("/foo/bar.txt");
const buf = new Uint8Array(100);
const numberOfBytesRead = file.readSync(buf); // 11 bytes
const text = new TextDecoder().decode(buf); // "hello world"
```
number | null