Use the trim_space function in APL to remove leading and trailing whitespace characters from a string. This function is especially useful when cleaning up input from logs, APIs, or user-generated content where strings may contain unintended spaces. You can apply trim_space to normalize data before comparisons, joins, or aggregations that depend on exact string matches.
Use trim_space when you need to ensure that extraneous spaces at the beginning or end of a string don’t interfere with your analysis or results.
For users of other query languages
If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.
In Splunk, the trim function removes leading and trailing spaces. APL’s trim_space works similarly.
['sample-http-logs']
| extend cleaned_uri = trim_space(uri)In ANSI SQL, the TRIM() function removes leading and trailing whitespace by default. APL’s trim_space achieves the same behavior.
['sample-http-logs']
| extend cleaned_uri = trim_space(uri)Usage
Syntax
trim_space(value)Parameters
| Name | Type | Description |
|---|---|---|
| value | string | The input string to trim. |
Returns
A string with all leading and trailing whitespace removed. The function does not modify internal whitespace.
Use case examples
When analyzing request URIs from logs, trailing or leading spaces can lead to false negatives in equality comparisons. Use trim_space to normalize request paths.
Query
['sample-http-logs']
| extend cleaned_uri = trim_space(uri)
| summarize count() by cleaned_uriOutput
| cleaned_uri | count |
|---|---|
| /api/data | 120 |
| /api/data/submit | 88 |
| /login | 42 |
This query removes leading and trailing spaces from each uri and aggregates request counts by the cleaned path.
In OpenTelemetry traces, service names or span IDs can have unintended spaces when injected from external tools. Use trim_space to standardize span IDs before filtering.
Query
['otel-demo-traces']
| extend clean_span_id = trim_space(span_id)
| summarize count() by clean_span_idOutput
| clean_span_id | count |
|---|---|
| 53c9e2f4e8794a6a | 17 |
| a3ff4f1e5b9d1c22 | 14 |
| 12c4b9f7da984dc7 | 21 |
This query trims each span_id and aggregates span counts, ensuring ID formatting does not affect grouping.