---
title: Regex functions
description: Scalar functions for regular expressions
image: https://developers.cloudflare.com/dev-products-preview.png
---

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# Regex functions

_Cloudflare Pipelines scalar function implementations are based on[Apache DataFusion ↗](https://arrow.apache.org/datafusion/) (via [Arroyo ↗](https://www.arroyo.dev/)) and these docs are derived from the DataFusion function reference._

Cloudflare Pipelines uses a[PCRE-like ↗](https://en.wikibooks.org/wiki/Regular%5FExpressions/Perl-Compatible%5FRegular%5FExpressions)regular expression [syntax ↗](https://docs.rs/regex/latest/regex/#syntax) (minus support for several features including look-around and backreferences).

## `regexp_like`

Returns true if a [regular expression ↗](https://docs.rs/regex/latest/regex/#syntax) has at least one match in a string, false otherwise.

```

regexp_like(str, regexp[, flags])


```

**Arguments**

* **str**: String expression to operate on. Can be a constant, column, or function, and any combination of string operators.
* **regexp**: Regular expression to test against the string expression. Can be a constant, column, or function.
* **flags**: Optional regular expression flags that control the behavior of the regular expression. The following flags are supported:  
   * **i**: case-insensitive: letters match both upper and lower case  
   * **m**: multi-line mode: ^ and $ match begin/end of line  
   * **s**: allow . to match \\n  
   * **R**: enables CRLF mode: when multi-line mode is enabled, \\r\\n is used  
   * **U**: swap the meaning of x\* and x\*?

**Example**

```

select regexp_like('Köln', '[a-zA-Z]ö[a-zA-Z]{2}');

+--------------------------------------------------------+

| regexp_like(Utf8("Köln"),Utf8("[a-zA-Z]ö[a-zA-Z]{2}")) |

+--------------------------------------------------------+

| true                                                   |

+--------------------------------------------------------+

SELECT regexp_like('aBc', '(b|d)', 'i');

+--------------------------------------------------+

| regexp_like(Utf8("aBc"),Utf8("(b|d)"),Utf8("i")) |

+--------------------------------------------------+

| true                                             |

+--------------------------------------------------+


```

Additional examples can be found [here ↗](https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/regexp.rs)

## `regexp_match`

Returns a list of [regular expression ↗](https://docs.rs/regex/latest/regex/#syntax) matches in a string.

```

regexp_match(str, regexp[, flags])


```

**Arguments**

* **str**: String expression to operate on. Can be a constant, column, or function, and any combination of string operators.
* **regexp**: Regular expression to match against. Can be a constant, column, or function.
* **flags**: Optional regular expression flags that control the behavior of the regular expression. The following flags are supported:  
   * **i**: case-insensitive: letters match both upper and lower case  
   * **m**: multi-line mode: ^ and $ match begin/end of line  
   * **s**: allow . to match \\n  
   * **R**: enables CRLF mode: when multi-line mode is enabled, \\r\\n is used  
   * **U**: swap the meaning of x\* and x\*?

**Example**

```

select regexp_match('Köln', '[a-zA-Z]ö[a-zA-Z]{2}');

+---------------------------------------------------------+

| regexp_match(Utf8("Köln"),Utf8("[a-zA-Z]ö[a-zA-Z]{2}")) |

+---------------------------------------------------------+

| [Köln]                                                  |

+---------------------------------------------------------+

SELECT regexp_match('aBc', '(b|d)', 'i');

+---------------------------------------------------+

| regexp_match(Utf8("aBc"),Utf8("(b|d)"),Utf8("i")) |

+---------------------------------------------------+

| [B]                                               |

+---------------------------------------------------+


```

Additional examples can be found [here ↗](https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/regexp.rs)

## `regexp_replace`

Replaces substrings in a string that match a [regular expression ↗](https://docs.rs/regex/latest/regex/#syntax).

```

regexp_replace(str, regexp, replacement[, flags])


```

**Arguments**

* **str**: String expression to operate on. Can be a constant, column, or function, and any combination of string operators.
* **regexp**: Regular expression to match against. Can be a constant, column, or function.
* **replacement**: Replacement string expression. Can be a constant, column, or function, and any combination of string operators.
* **flags**: Optional regular expression flags that control the behavior of the regular expression. The following flags are supported:  
   * **g**: (global) Search globally and don't return after the first match  
   * **i**: case-insensitive: letters match both upper and lower case  
   * **m**: multi-line mode: ^ and $ match begin/end of line  
   * **s**: allow . to match \\n  
   * **R**: enables CRLF mode: when multi-line mode is enabled, \\r\\n is used  
   * **U**: swap the meaning of x\* and x\*?

**Example**

```

SELECT regexp_replace('foobarbaz', 'b(..)', 'X\\1Y', 'g');

+------------------------------------------------------------------------+

| regexp_replace(Utf8("foobarbaz"),Utf8("b(..)"),Utf8("X\1Y"),Utf8("g")) |

+------------------------------------------------------------------------+

| fooXarYXazY                                                            |

+------------------------------------------------------------------------+

SELECT regexp_replace('aBc', '(b|d)', 'Ab\\1a', 'i');

+-------------------------------------------------------------------+

| regexp_replace(Utf8("aBc"),Utf8("(b|d)"),Utf8("Ab\1a"),Utf8("i")) |

+-------------------------------------------------------------------+

| aAbBac                                                            |

+-------------------------------------------------------------------+


```

Additional examples can be found [here ↗](https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/regexp.rs)

## `position`

Returns the position of `substr` in `origstr` (counting from 1). If `substr` does not appear in `origstr`, return 0.

```

position(substr in origstr)


```

**Arguments**

* **substr**: The pattern string.
* **origstr**: The model string.

```json
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/pipelines/","name":"Pipelines"}},{"@type":"ListItem","position":3,"item":{"@id":"/pipelines/sql-reference/","name":"SQL reference"}},{"@type":"ListItem","position":4,"item":{"@id":"/pipelines/sql-reference/scalar-functions/","name":"Scalar functions"}},{"@type":"ListItem","position":5,"item":{"@id":"/pipelines/sql-reference/scalar-functions/regex/","name":"Regex functions"}}]}
```