function Deno.truncateSync
truncateSync(name: string,len?: number,): void
Synchronously truncates (or extends) the specified file, to reach the
specified `len`. If `len` is not specified then the entire file contents
are truncated.
### Truncate the entire file
```ts
Deno.truncateSync("my_file.txt");
```
### Truncate part of the file
```ts
const file = Deno.makeTempFileSync();
Deno.writeFileSync(file, new TextEncoder().encode("Hello World"));
Deno.truncateSync(file, 7);
const data = Deno.readFileSync(file);
console.log(new TextDecoder().decode(data));
```
Requires `allow-write` permission.
void