# How can i handle nil values in logstash

**URL:** <https://discuss.elastic.co/t/how-can-i-handle-nil-values-in-logstash/83074>\
**Category:** Logstash\
**Created:** [April 20, 2017, 2:47pm UTC](https://discuss.elastic.co/t/how-can-i-handle-nil-values-in-logstash/83074 "2017-04-20T14:47:09Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Dan](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@Dan](https://discuss.elastic.co/u/Dan)\
**Post date:** [April 20, 2017, 2:47pm UTC](https://discuss.elastic.co/t/how-can-i-handle-nil-values-in-logstash/83074/1 "2017-04-20T14:47:09Z")

</div>

I am using csv as input as shown below

firstname lastname

dinesh angari  
rajesh  
mahesh rangu

and i am using http as output and below is my filter

`mutate {add_field => {"newlastname" => "%{lastname}"} }`

but in the output when the lastname value is null i am getting **%{lastname}** value as newlastname

please help me how can i ignore null values.

Thanks in advance............................

---

<div class="post-metadata">

**Author:** ![pierhugues](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/pierhugues/32/48383_2.png) [@pierhugues](https://discuss.elastic.co/u/pierhugues)\
**Post date:** [April 28, 2017, 2:59pm UTC](https://discuss.elastic.co/t/how-can-i-handle-nil-values-in-logstash/83074/2 "2017-04-28T14:59:49Z")

</div>

You can wrap the plugin with a conditional like this to check for existence.

```auto
if [lastname] {
mutate {add_field => {"newlastname" => "%{lastname}"} }
}

```

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [May 26, 2017, 3:14pm UTC](https://discuss.elastic.co/t/how-can-i-handle-nil-values-in-logstash/83074/3 "2017-05-26T15:14:00Z")

</div>

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.