packer/website/content/docs/templates/hcl_templates/functions/string/substr.mdx

---
page_title: substr function reference
description: |-
  The `substr` function extracts a substring from a given string using an offset and
  length. 
---

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> [!IMPORTANT]  
> **Documentation Update:** Product documentation previously located in `/website` has moved to the [`hashicorp/web-unified-docs`](https://github.com/hashicorp/web-unified-docs) repository, where all product documentation is now centralized. Please make contributions directly to `web-unified-docs`, since changes to `/website` in this repository will not appear on developer.hashicorp.com.
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# `substr` Function

`substr` extracts a substring from a given string by offset and length.

```hcl
substr(string, offset, length)
```

## Examples

```shell-session
> substr("hello world", 1, 4)
ello
```

The offset and length are both counted in _unicode characters_ rather than
bytes:

```shell-session
> substr("🤔🤷", 0, 1)
🤔
```