method Deno.stdin.readSync
stdin.readSync(p: Uint8Array): number | null
Synchronously read from the incoming data from `stdin` 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 the text "hello world" is piped into the script:
const buf = new Uint8Array(100);
const numberOfBytesRead = Deno.stdin.readSync(buf); // 11 bytes
const text = new TextDecoder().decode(buf); // "hello world"
```
number | null