| --- |
| page_title: substr - Functions - Configuration Language |
| description: |- |
| The substr function extracts a substring from a given string by offset and |
| length. |
| --- |
| |
| # `substr` Function |
| |
| `substr` extracts a substring from a given string by offset and (maximum) length. |
| |
| ```hcl |
| substr(string, offset, length) |
| ``` |
| |
| ## Examples |
| |
| ``` |
| > substr("hello world", 1, 4) |
| ello |
| ``` |
| |
| The offset and length are both counted in _unicode characters_ rather than |
| bytes: |
| |
| ``` |
| > substr("🤔🤷", 0, 1) |
| 🤔 |
| ``` |
| |
| The offset index may be negative, in which case it is relative to the end of |
| the given string. The length may be -1, in which case the remainder of the |
| string after the given offset will be returned. |
| |
| ``` |
| > substr("hello world", -5, -1) |
| world |
| ``` |
| |
| If the length is greater than the length of the string, the substring |
| will be the length of all remaining characters. |
| |
| ``` |
| > substr("hello world", 6, 10) |
| world |
| ``` |
