What syntax is used to link key/value pairs in search strings?

In Splunk's Search Processing Language (SPL), a search string is fundamentally built upon key-value pairs to filter and analyze data. The syntax used to link a key (a field name) to its corresponding value is a relational operator. The most common operator is the equals sign (=), but other relational operators such as not equal (!=), greater than (>), and less than (<) are also used to establish the relationship between the field and the value being searched for. This syntax is the primary method for specifying search criteria.

A. Parentheses: Parentheses are used for grouping boolean expressions to control the order of evaluation (e.g., (error OR fail) AND status=503), not for linking keys to values.

B. @ or # symbols: These symbols have specific functions in SPL, such as time rounding with the @ symbol, but they are not used to link keys and values in a search filter.

C. Quotation marks: Quotation marks are used to enclose values that contain spaces, special characters, or boolean operators, ensuring they are treated as a single literal string (e.g., user="john doe"). They define the value, but do not link it to the key.

1. Splunk Enterprise Documentation

Search Manual

Version 9.2.1

"Specify field-value pairs in your search".

This section explicitly states: "A field-value pair consists of a field name

an operator

and the value you are searching for. The most common operator is the equals sign ( = ). For example

to search for events with the status code of 200

you specify status=200." This directly confirms the use of relational operators.

2. Splunk Enterprise Documentation

Search Manual

Version 9.2.1

"SPL syntax basics".

Under the "Comparison and Conditional functions" subsection

the documentation lists comparison operators used in search strings

including =

!=

<

>

<=

and >=. This reinforces that these operators are the standard syntax for linking fields and values.

3. Splunk Enterprise Documentation

Search Tutorial

"Step 2: Specify a field and value".

This official tutorial demonstrates the core syntax: "To search for a value in a specific field

use the syntax field="value" or field=value." It highlights the equals sign (=) as the linking mechanism between the field (key) and the value.