method Deno.FsFile.prototype.truncateSync
FsFile.prototype.truncateSync(len?: number): void
Synchronously truncates (or extends) the file to reach the specified
`len`. If `len` is not specified, then the entire file contents are
truncated.
### Truncate the entire file
```ts
using file = Deno.openSync("my_file.txt", { write: true });
file.truncateSync();
```
### Truncate part of the file
```ts
// if "my_file.txt" contains the text "hello world":
using file = Deno.openSync("my_file.txt", { write: true });
file.truncateSync(7);
const buf = new Uint8Array(100);
file.readSync(buf);
const text = new TextDecoder().decode(buf); // "hello w"
```
void