# Replacement across all fields with single rule
**URL:** https://discuss.elastic.co/t/replacement-across-all-fields-with-single-rule/27081
**Category:** Logstash
**Created:** [August 9, 2015, 5:04am UTC](https://discuss.elastic.co/t/replacement-across-all-fields-with-single-rule/27081 "2015-08-09T05:04:34Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@KrishnaPG](https://discuss.elastic.co/u/KrishnaPG)
#### Post date: [August 9, 2015, 5:04am UTC](https://discuss.elastic.co/t/replacement-across-all-fields-with-single-rule/27081/1 "2015-08-09T05:04:34Z")
I have around 40 fields of numeric data in csv format and occasionally multiple fields in a row could be invalid values (indicated with, say, hyphen **-** ).
In the logstash is there a way to define a single generic mutate rule that works on all the fields to convert the hyphen ( **-** ) into numeric zero ( **0** ).
Right now, I have to have mutate rule once for each field, which is not really good way. For example,
```
csv { columns => [col1, col2, col3, .... col40] }
mutate {
gsub => [
"col1", "-", 0,
"col2", "- ", 0,
....
]
}
}
```
Is there a much better simpler way to achieve this than to manually specify the same rule 40 times?
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [August 9, 2015, 7:41am UTC](https://discuss.elastic.co/t/replacement-across-all-fields-with-single-rule/27081/2 "2015-08-09T07:41:10Z")
You'd have to use a [ruby filter](https://www.elastic.co/guide/en/logstash/current/plugins-filters-ruby.html). Untested example:
```
filter {
ruby {
code => '
event.to_hash.each { |k, v|
event[k] = 0 if v == "-"
}
'
}
}
```
---
### Author:  [@KrishnaPG](https://discuss.elastic.co/u/KrishnaPG)
#### Post date: [August 9, 2015, 11:39am UTC](https://discuss.elastic.co/t/replacement-across-all-fields-with-single-rule/27081/3 "2015-08-09T11:39:59Z")
Thanks @magnusbaeck I am not familiar with Ruby. Will try to look into it.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 5:32am UTC](https://discuss.elastic.co/t/replacement-across-all-fields-with-single-rule/27081/4 "2017-07-06T05:32:31Z")