# Ruby filter logstash (.length)
**URL:** https://discuss.elastic.co/t/ruby-filter-logstash-length/304832
**Category:** Logstash
**Created:** [May 16, 2022, 2:10pm UTC](https://discuss.elastic.co/t/ruby-filter-logstash-length/304832 "2022-05-16T14:10:44Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@alex\_vermex](https://discuss.elastic.co/u/alex_vermex)
#### Post date: [May 16, 2022, 2:10pm UTC](https://discuss.elastic.co/t/ruby-filter-logstash-length/304832/1 "2022-05-16T14:10:44Z")
Hi,
I would like to fix the length of message
logstash.conf:
```auto
filter {
mutate {
split => {"message" => "|"}
ruby {
code => "event.set('number_of_elements', event.get('message').length) "
}
add_field => { "DateTime" => "%{[message][0]}" }
add_field => { "version" => "%{[message][1]}" }
.............................
if (number_of_elements == 36) {
mutate {
add_field => {"Status Login" => "%{[message][31]}"}
........................
}
}
}
```
it gives me an error at ruby filter
```auto
ruby ", :backtrace=>["D:/elastic_stack/logstash-7.16.3/logstash-core/lib/logstash/compiler.rb:32:in `compile_imperative'", "org/logstash/execution/AbstractPipelineExt.java:187:in `initialize'", "org/logstash/execution/JavaBasePipelineExt.java:72:in `initialize'", "D:/elastic_stack/logstash-7.16.3/logstash-core/lib/logstash/java_pipeline.rb:47:in `initialize'", "D:/elastic_stack/logstash-7.16.3/logstash-core/lib/logstash/pipeline_action/create.rb:52:in `execute'", "D:/elastic_stack/logstash-7.16.3/logstash-core/lib/logstash/agent.rb:383:in `block in converge_state'"]}
[2022-05-16T14:08:33,035][INFO][logstash.runner] Logstash shut down.
[2022-05-16T14:08:33,047][FATAL][org.logstash.Logstash] Logstash stopped processing because of an error: (SystemExit) exit
org.jruby.exceptions.SystemExit: (SystemExit) exit
at org.jruby.RubyKernel.exit(org/jruby/RubyKernel.java:747) ~[jruby-complete-9.2.20.1.jar:?]
at org.jruby.RubyKernel.exit(org/jruby/RubyKernel.java:710) ~[jruby-complete-9.2.20.1.jar:?]
at D_3a_.elastic_stack.logstash_minus_7_dot_16_dot_3.lib.bootstrap.environment.(D:\elastic_stack\logstash-7.16.3\lib\bootstrap\environment.rb:94) ~[?:?]
```
Did I do something wrong?
Thanks.
---
### Author:  [@aaron-nimocks](https://discuss.elastic.co/u/aaron-nimocks)
#### Post date: [May 16, 2022, 2:32pm UTC](https://discuss.elastic.co/t/ruby-filter-logstash-length/304832/2 "2022-05-16T14:32:12Z")
Think your issue was not using mutate when doing a split. This works below.
**Conf**
```auto
input { generator { count => 1 lines => ['{ "msg": "1|2|3|4|5|6" }'] codec => json } }
filter {
mutate {
split => { "msg" => "|" }
}
ruby {
code => "event.set('number_of_elements', event.get('msg').length) "
}
}
output { stdout { codec => "json_lines" } }
```
**Output**
```auto
"number_of_elements": 6
```
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [June 13, 2022, 2:33pm UTC](https://discuss.elastic.co/t/ruby-filter-logstash-length/304832/3 "2022-06-13T14:33:08Z")
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