# Creating a new field based on substring

**URL:** https://discuss.elastic.co/t/creating-a-new-field-based-on-substring/135248
**Category:** Logstash
**Created:** [June 10, 2018, 12:18am UTC](https://discuss.elastic.co/t/creating-a-new-field-based-on-substring/135248 "2018-06-10T00:18:57Z")
**Posts on this page:** 1
**Showing post:** 2

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### Author: ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [June 10, 2018, 1:20am UTC](https://discuss.elastic.co/t/creating-a-new-field-based-on-substring/135248/2 "2018-06-10T01:20:00Z")

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[This](https://discuss.elastic.co/t/extracting-a-substring/134268) provides an example of extracting a fixed number of characters as a prefix to a field.

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_[View the full topic](https://discuss.elastic.co/t/creating-a-new-field-based-on-substring/135248)._