Is it possible to create a custom script that is a search command that can take in the search's results, do something, and then return the new results to splunk in a different language than python?
Yes, you can. You can create custom search commands with languages other than Python.
https://dev.splunk.com/enterprise/docs/devtools/customsearchcommands/nonpythonscscs
Are the non custom search commands able to get the results from splunk, manipulate them and create new fields and then send them back to splunk or can I only do logging or send an alert that the search is done?
I was trying to create a script with golang but it keeps saying my command can't find the go.path file which I was copying from the java example that you linked.
Custom search command are to be used within search pipeline. Typical use case is performing an "external lookup" (for example, calling a whois database).
What you're referring to as sending an alert message is not a custom search command but custom alert action and that's something different.
Did you put the go.path file in the bin directory of your app?
I actually want to use it in the search pipeline for a lookup like your example a whois call. The go.path is in the bin directory of my app.
Maybe BASH could work?
#!/bin/bash
/opt/splunk/bin/splunk cmd search [object][-parameter <value>]
https://docs.splunk.com/Documentation/SplunkCloud/latest/SearchReference/CLIsearchsyntax
Then add to the script whatever commands you're looking to do something with.
That is running everything from the custom script. I need to be able to call the script from the search in splunk instead.
Edit: But I could just wrap the other script inside a python/bash file.