What command is used to create a field extraction in Splunk?

Creating a field extraction in Splunk is commonly accomplished using the rex command. This command allows users to create fields on the fly by extracting them based on regular expressions from the raw event data.

When using the rex command, you specify a regular expression that matches the desired pattern within your events, and Splunk will generate new fields based on that pattern. This is particularly useful for extracting specific information from unstructured data, allowing for more in-depth analysis and reporting.

The other commands listed don't serve the same purpose. While the extract command might imply a process of retrieving fields, it is not used for creating new field extractions. The field command typically displays the value of existing fields but does not create new ones. The regex command pertains to regular expressions but doesn't directly interface with Splunk in the same way as the rex command does for field extraction.