The truncate module preserves only the first N characters (or bytes when using binary mode) of enumerated values. For example, to truncate all but the first 20 characters of the EV “Message”:

tag=data json IP Message | truncate Message 20 | table

truncate only operates on string and byte slice enumerated values and by default assumes data is UTF-8 encoded. You can override this behavior by using the -binary flag.

Supported Options#

  • -ellipsis: Optional. Add an ellipsis (three period characters, “…”) to the string after truncating, meaning all truncated values will be three characters longer than specified.

  • -binary: Optional. Treat data as byte slices instead of UTF-8 strings.


In this example, we extract requests from DNS:

tag=dns json Question.Hdr.Name | table

Example 1

We can truncate, and add back an ellipsis, using the truncate module:

tag=dns json Question.Hdr.Name 
| truncate -ellipsis Name 10 
| table

Example 2