> ## Documentation Index > Fetch the complete documentation index at: https://docs.chronosphere.io/llms.txt > Use this file to discover all available pages before exploring further. # Search/replace value export const entity_0 = "search/replace value processing rule" The search/replace value [processing rule](/ingest/pipeline/processing-rules) uses regular expressions to search for a value inside a string, then replaces that value with a different specified value. ## Configuration parameters Use the parameters in this section to configure the {entity_0}. The Telemetry Pipeline web interface uses the items in the **Name** column to describe these parameters. [Pipeline configuration files](/ingest/pipeline/v2/configure/config-files) use the items in the **Key** column as YAML keys. | Name | Key | Description | Default | | ----------------------------------- | ------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------ | | **Key** | `key` | Required. The key whose value contains the string to replace. | *none* | | **Regex** | `regex` | Required. The regular expression that determines which values to replace. You can use capture groups to specify more than one value. | *none* | | **Match case** checkbox | `matchCase` | Indicates whether the regular expression is case-sensitive. | Not selected | | **Maximum number of substitutions** | `submax` | The maximum number of substitutions that this rule will perform within a given record. | *none* | | **Replacement value** | `replacement` | Required. The regular expression substitution pattern to replace the values specified by **Regex**. You can use the `%` character to use capture groups in your substitution pattern. | *none* | | **Regex engine** | `regexEngine` | Required. The [engine](/ingest/pipeline/processing-rules#regex-engines) to parse your regular expression. Accepted values: `GNU`, `Oniguruma`, `PCRE2`, `POSIX`, `TRE`. | `PCRE2` | | **Comment** | `comment` | A custom note or description of the rule's function. This text is displayed next to the rule's name in the **Actions** list in the processing rules interface. | *none* | ## Examples Using the search/replace value rule lets you modify and overwrite your telemetry data. ### Basic substitution For example, given these sample logs: ```json theme={null} {"timestamp":"2023-03-28T09:08:41.64283645Z","user_id":3,"page_id":30,"action":"purchase"} {"timestamp":"2023-03-28T09:08:42.643343109Z","user_id":4,"page_id":10,"action":"purchase"} {"timestamp":"2023-03-28T09:08:48.643600498Z","user_id":1,"page_id":50,"action":"click"} {"timestamp":"2023-03-28T09:08:50.643773688Z","user_id":5,"page_id":40,"action":"purchase"} {"timestamp":"2023-03-28T09:08:51.643932272Z","user_id":1,"page_id":30,"action":"purchase"} {"timestamp":"2023-03-28T09:08:56.644080944Z","user_id":2,"page_id":40,"action":"click"} {"timestamp":"2023-03-28T09:09:03.64425954Z","user_id":3,"page_id":30,"action":"click"} {"timestamp":"2023-03-28T09:09:03.644317046Z","user_id":1,"page_id":20,"action":"view"} {"timestamp":"2023-03-28T09:09:10.64447719Z","user_id":2,"page_id":50,"action":"purchase"} {"timestamp":"2023-03-28T09:09:17.644810963Z","user_id":2,"page_id":10,"action":"view"} {"timestamp":"2023-03-28T09:09:20.644994805Z","user_id":1,"page_id":50,"action":"view"} ``` A processing rule with the **Key** value `action`, the **Regex** value `purchase`, and the **Replacement** value `checkout` returns the following result: ```json theme={null} {"user_id":3,"page_id":30,"timestamp":"2023-03-28T09:08:41.64283645Z","action":"checkout"} {"user_id":4,"page_id":10,"timestamp":"2023-03-28T09:08:42.643343109Z","action":"checkout"} {"user_id":1,"page_id":50,"timestamp":"2023-03-28T09:08:48.643600498Z","action":"click"} {"user_id":5,"page_id":40,"timestamp":"2023-03-28T09:08:50.643773688Z","action":"checkout"} {"user_id":1,"page_id":30,"timestamp":"2023-03-28T09:08:51.643932272Z","action":"checkout"} {"user_id":2,"page_id":40,"timestamp":"2023-03-28T09:08:56.644080944Z","action":"click"} {"user_id":3,"page_id":30,"timestamp":"2023-03-28T09:09:03.64425954Z","action":"click"} {"user_id":1,"page_id":20,"timestamp":"2023-03-28T09:09:03.644317046Z","action":"view"} {"user_id":2,"page_id":50,"timestamp":"2023-03-28T09:09:10.64447719Z","action":"checkout"} {"user_id":2,"page_id":10,"timestamp":"2023-03-28T09:09:17.644810963Z","action":"view"} {"user_id":1,"page_id":50,"timestamp":"2023-03-28T09:09:20.644994805Z","action":"view"} ``` This rule searched for the string `purchase` within the value of the `action` key, then replaced any matching strings with the value `checkout`. ### Capture groups You can also use capture groups for more complex replacements. For example, given these sample logs: ```json theme={null} {"event":"Sign-on detected from user 'Alice' to server 83ad48."} {"event":"Sign-on detected from user 'Bob' to server d6f442."} {"event":"Sign-on detected from user 'Carol' to server fb65ee."} {"event":"Sign-on detected from user 'Dave' to server e6ec7d."} {"event":"Sign-on detected from user 'Erin' to server b0692c."} {"event":"Sign-on detected from user 'Frank' to server 1c7cd2."} {"event":"Sign-on detected from user 'Grace' to server 9626a3."} ``` A processing rule with the **Key** value `event`, the **Regex** value `Sign-on detected from user '(.*)' to server (.*).`, and the **Replacement** value `login: %1 at %2` returns the following result: ```json theme={null} {"event":"login: Alice at 83ad48"} {"event":"login: Bob at d6f442"} {"event":"login: Carol at fb65ee"} {"event":"login: Dave at e6ec7d"} {"event":"login: Erin at b0692c"} {"event":"login: Frank at 1c7cd2"} {"event":"login: Grace at 9626a3"} ``` This rule searched for username and server name strings within the value of the `event` key, then replaced the value of `event` with a shorter message that still retained the names contained in the original message.