---
name: "bson_append_regex_w_len"
section: "3"
platform: "linux"
package: "libbson-doc"
version: "1.30.4-1+deb13u3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/bson_append_regex_w_len"
---

# bson\_append\_regex\_w\_len(3)

## SYNOPSIS

```
bool
bson_append_regex_w_len (bson_t *bson,
                          const char *key,
                          int key_length,
                          const char *regex,
                          int regex_length,
                          const char *options);
```

## PARAMETERS

- •

  **bson**: A *bson\_t*.

- •

  **key**: An ASCII C string containing the name of the field.

- •

  **key\_length**: The length of **key** in bytes, or -1 to determine the length with **strlen()**.

- •

  **regex**: An ASCII string containing the regex.

- •

  **regex\_length**: The length of **regex** in bytes, or -1 to determine the length with **strlen()**.

- •

  **options**: An optional string containing the regex options as a string.

## DESCRIPTION

Appends a new field to **bson** of type BSON\_TYPE\_REGEX. **regex** should be the regex string. **options** should contain the options for the regex.

Valid characters for **options** include:

- •

  **'i'** for case-insensitive.

- •

  **'m'** for multiple matching.

- •

  **'x'** for verbose mode.

- •

  **'l'** to make w and W locale dependent.

- •

  **'s'** for dotall mode ('.' matches everything)

- •

  **'u'** to make w and W match unicode.

## RETURNS

Returns **true** if the operation was applied successfully. The function will fail if appending the regex grows **bson** larger than INT32\_MAX.

## AUTHOR

MongoDB, Inc

## COPYRIGHT

2009-present, MongoDB, Inc.