eval command

The eval command can be used with either table data or event data.If used with event data the new field that is created won't be shown, because the event tab only shows the event data as a whole. Duh.

To show the new field that you have created then you will have to use the table command to include that new field.

Important note

If you use eval command with field names that include non-alphanumeric characters, other than '_', you must surround the field with single quotation marks. For example, if you are using 'server-1' field in your eval expression then you must do it like so

eval new=count+'server-1'

Inline eval

If you use inline eval with commands such as stats / chart then you can evaluate new fields using the existing ones, you just need to use the AS to assign it to a new column. As opposite from doing variable=<expression>