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.
• For the list of eval functions, see Evaluation functions in the Search Reference.
• Also, you can read more about using the eval command to evaluate and manipulate fields in another section in this manual.

Example 1: Distinct counts of matching events

This example counts the IP addresses where the errors originate. This is similar to a search for events that is filtered for a specific error code, and then used with the stats command to count the IP addresses.

status=404 | stats dc(ip)

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

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

Example 2: Categorizing and counting fields

This example uses sample email data. You should be able to run this search on any email data by replacing the sourcetype=cisco:esa with the sourcetype value and the mailfrom field with email address field name in your data. For example, the email might be To, From, or Cc).

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

The eval command in this search contains two expressions, separated by a comma.

sourcetype="cisco:esa" mailfrom=* | eval accountname=split(mailfrom,"@"), 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 part of this search uses the eval command to break up the email address in the mailfrom field. The from_domain is defined as the portion of the mailfrom field after the @ symbol.
  • The split() function is used to break the mailfrom field into a multivalue field called accountname. The first value of accountname is everything before the "@" symbol, and the second value is everything after.
  • The mvindex() function is used to set from_domain to the second value in the multivalue field accountname.
• The results are then piped into the stats command. The count() function is used to count the results of the eval expression.
• Theeval 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.

The results appear on the Statistics tab and look something like this:

.com	.net	.org	other
4246	9890	0	3543