Field expressions

When you add data, Splunk software extracts pairs of information and saves them as fields. Some fields are common to all events, but others are not. Adding fields to your search term gives you a better chance of matching specific events.

If you are searching web access logs for specific HTTP status errors, instead of searching for "web error 404", you can use fields to search for:

status=404

See Use fields to retrieve events.

Use comparison operators to match field values

You can use comparison operators to match a specific value or a range of field values.

Operator	Example	Result
=	field=foo	Multivalued field values that exactly match "foo".
!=	field!=foo	Multivalued field values that don't exactly match "foo".
<	field<x	Numerical field values that are less than x.
>	field>x	Numerical field values that are greater than x.
<=	field<=x	Numerical field values that are less than and equal to x.
>=	field>=x	Numerical field values that are greater than and equal to x.

For example, to find events that have a delay field that is greater than 10:

delay > 10

When quotes are required in field expressions

When the value you are searching for contains a breaking character, you must enclose the value in quotation marks.

Examples of breaking characters are spaces, commas, pipes, square brackets, and equals signs. In addition, to search for reserved keywords such as AND, OR, and NOT you must use quotation marks.

Field values that match SPL operators or keywords

There are several field values that match SPL operators or keywords, such as AS, AND, IN, and OR. Here are a few examples:

• country=IN for India
• country=AS or state=AS for American Samoa
• iso=AND for Andorra
• state=OR for Oregon

To search for field values that match operators or keywords, you must enclose the value in quotation marks. For example: country="IN".