When defining string fields in Cortex Query Language (XQL) queries, it's important to understand the various string manipulations available and the syntax required to build effective queries that return the results you're expecting. Cortex Query Language (XQL) uses [RE2](https://github.com/google/re2/wiki/Syntax) for its regular expression implementation.
Cortex XSIAM enables you to use single double quotes (`"<text>"`) or triple double quotes (`"""<text>"""`) when defining your XQL syntax for string manipulation. This specific syntax is used with different stages, functions, and operators, with or without wildcards. Typically, the `alter` and `filter` stages are used with single or triple double quotes, so these stages are used in the examples provided below.
### Using single double quotes
Single double quotes (`"<text>"`) include the following functionality:
* Treats the string value literally.
* Wildcards using the asterisk (\*) are processed as XQL wildcards, and match any sequence of characters.
* Escape sequences, such as `\n` (new line) or `\t` (tab), are not processed and are treated as plain characters.
Example
`"\test\"` means to look for `\test\`
### Using triple double quotes
Triple double quotes (`"""<text>"""`) include the following functionality:
* Enables regex-style pattern matching and escape sequence interpretation.
* Escape sequences, such as `\n` (new line) or `\t` (tab), are processed.
* Wildcards using the asterisk (\*) are processed as XQL wildcards, and match any sequence of characters.
Example
`"""\\test\\"""` means to look for `\test\`
**Understanding the results**:
* The double backslashes (`\\`) at the beginning becomes a single backlash (`\`) as it's processed as an escaped backslash.
* `test` is interpreted as literal.
* The double backslashes (`\\`) at the end becomes a single backlash (`\`) as it's processed as an escaped backslash.
### Query example using alter
When using the `alter` stage, you can use both single (`"<text>"`) and triple (`"""<text>"""`) double quotes when specifying string values. The difference lies in how special characters and pattern matching are interpreted.
Example
```programlisting
config timeframe = 10y
| dataset = test_dataset
| limit 1
| alter test = "\test\"
| alter test_triple = """\\\test\\"""
| fields test, test_triple
```
**Understanding the query and results**
* `test` field using single double quotes:
* The field value is `"\test\"`.
* The output results display `\test\` exactly as defined in the field value as no escape sequences are processed.
* `test_triple` field using triple double quotes:
* The field value is `"""\\\test\\"""`.
* The output results display `\ est\` (with a tab between `\` and the text `est`) because:
* `\\`: First two backslashes become single backslash `\`.
* `\t`: Interpreted as a tab.
* `est`: Is interpreted as literal.
* `\\`: Last two backslashes become single backslash `\`.
### Query example using filter
When using the `filter` stage, you can use both single (`"<text>"`) and triple (`"""<text>"""`) double quotes when specifying string values. The difference lies in how special characters and pattern matching are interpreted.
The examples provided are based on the following data table for a dataset called `test_dataset`:
| \_TIME | TEST |
| ---------------------- | --------- |
| Mar 26th 2022 19:26:07 | 12\t3 |
| May 7th 2023 15:16:00 | 12 3 |
| Jun 8th 2024 16:56:27 | 1233 |
| Mar 26th 2024 19:26:07 | 123 |
| Apr 5th 2024 11:21:02 | 12\t34563 |
| Apr 9th 2025 13:22:22 | 1233345 |
| May 9th 2025 13:22:22 | 12 35897 |
| May 30th 2025 21:45:02 | 116 |
Example 86.
```programlisting
config timeframe = 10y
| dataset = test_dataset
| filter test = "12\t3*"
| fields test
```
**Output results table**:
| \_TIME | TEST |
| ---------------------- | --------- |
| Mar 26th 2022 19:26:07 | 12\t3 |
| Apr 5th 2024 11:21:02 | 12\t34563 |
**Explanation of results**:
The asterisk (`*`) in `"12\t3*"` means to process the string field as an XQL wildcard by matching any sequence of characters that begins with `12\t3`. In addition, the `\t` characters are not processed as an escape character, but as plain characters.
Example 87.
```programlisting
config timeframe = 10y
| dataset = test_dataset
| filter test = """12\t3*"""
| fields test
```
**Output results table**:
| \_TIME | TEST |
| --------------------- | -------- |
| May 7th 2023 15:16:00 | 12 3 |
| May 9th 2025 13:22:22 | 12 35897 |
**Explanation of results**:
The `\t` in `"""12\t3*"""` is processed as a tab escape character. The asterisk (`*`) in `"""12\t3*"""` means to process the string field as an XQL wildcard by matching any sequence of characters that begins with `12<tab>3`.