> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/perl6-rosettacode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/c/check_output_device_is_a_terminal.md).

# Check output device is a terminal

The .t method on a filehandle tells you whether it's going to the terminal. Here we use the note function to emit our result to standard error rather than standard out.

```
$ raku -e 'note $*OUT.t'
True
$ raku -e 'note $*OUT.t' >/dev/null
False
```