Can we have a dash in the generated rex field name?

[danielbb]

The following works just fine -

 | makeresults 
 | eval temp="IP-Group={xxxx} {yyyy} {zzz}" 
 | rex field=temp max_match=0 "\{(?P<result>[^}]+)"

But the following breaks -

 | makeresults 
 | eval temp="IP-Group={xxxx} {yyyy} {zzz}" 
 | rex field=temp max_match=0 "\{(?P<re-sult>[^}]+)"

Saying - Error in 'rex' command: Encountered the following error while compiling the regex '\{(?P<re-sult>[^}]+)': Regex: syntax error in subpattern name (missing terminator).

Adding the dash, making it re-sult, broke it. Is there a way around it?

regex101 doesn't like it either...

[dindu · Accepted solution]

Hi Daniel,

Splunk has some restriction on naming field names.
This limits us from having a hyphen .

Please read on the below.

https://docs.splunk.com/Documentation/Splunk/7.3.1/Data/Configureindex-timefieldextraction.

Field name syntax restrictions
You can assign field names as follows:

Valid characters for field names are a-z, A-Z, 0-9, or _ .
Field names cannot begin with 0-9 or _ . Splunk reserves leading underscores for its internal variables.
Avoid assigning field names that match any of the default field names.

Do not assign field names that contain international characters.

However, we could use an eval command to generate a field with hyphen.
Eval operates only at the search time. Please test and let us know

| makeresults 
| eval temp="IP-Group={xxxx} {yyyy} {zzz}" 
| rex field=temp max_match=0 "\{(?P<result>[^}]+)"
|eval re-sult=result

[danielbb]

@dindu - |eval re-sult=result works like a charm.

It would be nice to know why "\{(?P<re-sult>[^}]+)" breaks even at the regex level.

[dindu]

Hi Daniel,

The field extracted is shown in the list of fields on the sidebar which implies the naming should satisfy the condition.
Whereas the eval is just happening on the front end Splunk UI.

Please accept if this helped.