# How to replace multiple new lines with one in Ingest Pipeline gsub

**URL:** <https://discuss.elastic.co/t/how-to-replace-multiple-new-lines-with-one-in-ingest-pipeline-gsub/350127>\
**Category:** Elasticsearch\
**Tags:** ingest-pipeline\
**Created:** [December 29, 2023, 12:39pm UTC](https://discuss.elastic.co/t/how-to-replace-multiple-new-lines-with-one-in-ingest-pipeline-gsub/350127 "2023-12-29T12:39:05Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![stephenb](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/stephenb/32/40856_2.png) [@stephenb](https://discuss.elastic.co/u/stephenb)\
**Post date:** [December 29, 2023, 4:57pm UTC](https://discuss.elastic.co/t/how-to-replace-multiple-new-lines-with-one-in-ingest-pipeline-gsub/350127/4 "2023-12-29T16:57:34Z")

</div>

> [@Bowfish](#):
>
> If there are more than one newlines in the string it should substitute the multiple newlines with one newline. If there is only one newline it should keep it.

Now it is just a regex exercise I am not a regex expert... but I did a quick google search found [this](https://stackoverflow.com/a/701658)

```auto
POST _ingest/pipeline/_simulate
{
  "pipeline": {
    "processors": [
      {
        "gsub": {
          "field": "message",
          "pattern": "\\\n+",
          "replacement": "\\\n",
          "ignore_missing": false,
          "description": "Replace multiple newlines",
          "on_failure": [
            {
              "append": {
                "description": "Record error information",
                "field": "_ingestion_errors",
                "value": "Processor 'gsub' with tag 'remove_page_numbers' in pipeline '{{ _ingest.on_failure_pipeline }}' failed with message '{{ _ingest.on_failure_message }}'"
              }
            }
          ]
        }
      }
    ]
  },
  "docs": [
    {
      "_source": {
        "message": """String with 
1 newline
Then 2 newlines

Then 3 Newlines

The End """
      }
    }
  ]
}

# Result
{
  "docs": [
    {
      "doc": {
        "_index": "_index",
        "_version": "-3",
        "_id": "_id",
        "_source": {
          "message": """String with 
1 newline
Then 2 newlines
Then 3 Newlines
The End """
        },
        "_ingest": {
          "timestamp": "2023-12-29T16:58:37.484845559Z"
        }
      }
    }
  ]
}

```

---

_[View the full topic](https://discuss.elastic.co/t/how-to-replace-multiple-new-lines-with-one-in-ingest-pipeline-gsub/350127)._