trim_end

This page explains how to use the trim_end function in APL.

The trim_end function removes all trailing occurrences of specified characters from a string. Use this function to clean log data, remove trailing whitespace or punctuation, or standardize string formats by removing unwanted suffixes.

Usage

Syntax

trim_end(cutset, text)

Parameters

NameTypeRequiredDescription
cutsetstringYesA string containing characters to remove from the end.
textstringYesThe source string to trim.

Returns

Returns the source string with all trailing characters in the cutset removed.

Use case examples

Remove trailing slashes and query parameters from URIs for endpoint grouping.

Query

['sample-http-logs']
| extend cleaned_uri = trim_end('/?&', uri)
| summarize request_count = count() by cleaned_uri, method
| sort by request_count desc
| limit 10

Run in Playground

Output

cleaned_urimethodrequest_count
/api/usersGET2341
/api/ordersPOST1987
/api/productsGET1654

This query removes trailing slashes and query separator characters from URIs, enabling better endpoint aggregation.

Clean trailing characters from service names for consistent grouping.

Query

['otel-demo-traces']
| extend cleaned_service = trim_end('-_', ['service.name'])
| summarize span_count = count() by cleaned_service
| sort by span_count desc
| limit 10

Run in Playground

Output

cleaned_servicespan_count
frontend4532
checkout3421
cart2987

This query removes trailing hyphens and underscores from service names, standardizing naming conventions for analysis.

Clean trailing punctuation from user identifiers in security logs.

Query

['sample-http-logs']
| extend cleaned_id = trim_end('.,;!?', id)
| summarize attempts = count() by cleaned_id, status
| sort by attempts desc
| limit 10

Run in Playground

Output

cleaned_idstatusfailed_attempts
user12340145
admin40332

This query removes trailing punctuation from user IDs in authentication attempts, ensuring accurate counting when IDs have inconsistent formatting.

  • trim_start: Removes leading characters. Use this to trim from the beginning instead of the end.
  • trim: Removes both leading and trailing characters. Use this when you need to clean both ends.
  • trim_end_regex: Removes trailing matches using regex. Use this for pattern-based trimming.
  • replace_string: Replaces strings. Use this when you need to remove characters from anywhere, not just the end.

Other query languages