Search Manual

Use stats with eval expressions and functions

This topic discusses how to use eval expressions and functions within your stats calculation.

• For more information about the eval command and syntax, see the eval command in the Search Reference manual.
• For the list of eval functions, see Functions for eval and where in the Search Reference manual.
• Also, you can read more about using the eval command to evaluate and manipulate fields in this manual.

Example 1: Distinct counts of matching events

Let's say you have errors and you want to count the IP addresses where the errors originate. This is similar to a search for events, filtered for a specific code, and then used with the stats command to count the IP addresses:

... | search error=404 | stats dc(ip)

The best way to do this with an eval expression is:

... | stats dc(eval(if(error==404, ip, NULL))) AS dc_ip

Example 2: Categorizing and counting fields

Find out how much of your organization's email comes from .com, .net, .org, or other top level domains.

sourcetype="cisco_esa" mailfrom=* | eval accountname=split(mailfrom,"@") | eval from_domain=mvindex(accountname,-1) | stats count(eval(match(from_domain, "[^\n\r\s]+\.com"))) AS ".com", count(eval(match(from_domain, "[^\n\r\s]+\.net"))) AS ".net", count(eval(match(from_domain, "[^\n\r\s]+\.org"))) AS ".org", count(eval(NOT match(from_domain, "[^\n\r\s]+\.(com|net|org)"))) AS "other"

The first half of this search uses eval to break up the email address in the mailfrom field and define the from_domain as the portion of the mailfrom field after the @ symbol.

The results are then piped into the stats command. The count() function is used to count the results of the eval expression. Here, eval uses the match() function to compare the from_domain to a regular expression that looks for the different suffixes in the domain. If the value of from_domain matches the regular expression, the count is updated for each suffix, .com, .net, and .org. Other domain suffixes are counted as other.

This produces the following results table:

Note: This example used generated email data (sourcetype=cisco_esa). You should be able to run this example on any email data by replacing the sourcetype=cisco_esa with your data's sourcetype value and the mailfrom field with your data's email address field name (for example, it might be To, From, or Cc).