> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/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/sidef-lang/programming_tasks/e/environment_variables.md).

# Environment variables

The `ENV` hash maps environment variables to their values:

```ruby
say ENV{'HOME'}
```