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Regex Library

What Is the Regex Library
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Cribl Stream ships with a Regex Library that contains a set of pre-built common regular expression patterns. This library serves as an easily accessible repository of regular expressions. The Library is searchable, and you can assign tags to each pattern for further organization or categorization.

To access the library, select Worker Groups from the sidebar, and choose a Worker Group. Then, on the Worker Groups submenu, select Processing, then Knowledge, then Regexes.

Regex Library
Regex Library

Using Library Patterns
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To insert a pattern into a Function’s regex field, first select the Advanced mode button Advanced mode or Edit button Edit icon beside that field.

In the resulting Regex or Rules modal, Regex Library patterns will appear as typeahead options. Select a pattern to paste it in. You can then use the pattern as-is, or modify it as necessary.

Inserting a pattern from the Regex Library
Inserting a pattern from the Regex Library

Adding Patterns to the Library
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You can also add new, custom patterns to the Library. In the same modal, once you’ve built your pattern, select Save to Library.

Adding a custom pattern to the Regex Library from a Function’s Regex modal
Adding a custom pattern to the Regex Library from a Function’s Regex modal

In the resulting modal, give your custom pattern a unique ID. Optionally, you can also provide a Description (name) and groom the Sample data. Then select Save.

Identifying the custom pattern
Identifying the custom pattern

Your custom pattern will now reside in the Regex Library. It will be available to Functions using the same typeahead assist as Cribl’s pre-built patterns.

Cribl vs. Custom and Priority
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Within the Library, patterns shipped by Cribl will be listed under the Cribl tab, while those built by users will be found under Custom. Over time, Cribl Stream will ship more patterns, and this distinction allows for both sets to grow independently.

In the case of an ID/Name conflict, the Custom pattern takes priority in listings and search. For example, if a Cribl-provided pattern and a Custom one are both named ipv4, the one from Cribl will not be displayed or delivered as a search result.