truncate method

Future<void> truncate(
  1. String name, [
  2. num? len
])

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

await Deno.truncate("my_file.txt");

Truncate part of the file

const file = await Deno.makeTempFile();
await Deno.writeFile(file, new TextEncoder().encode("Hello World"));
await Deno.truncate(file, 7);
const data = await Deno.readFile(file);
console.log(new TextDecoder().decode(data));  // "Hello W"

Requires allow-write permission.

Implementation

_i2.Future<void> truncate(
  _i2.String name, [
  _i2.num? len,
]) =>
    _i3.promiseToFuture(_i3.callMethod(
      this,
      'truncate',
      [
        name,
        len ?? _i6.undefined,
      ],
    ));