trim_start()

Applies to: ✅ Azure Data ExplorerAzure MonitorMicrosoft Sentinel

Removes leading match of the specified regular expression.

Syntax

trim_start(regex, source)

Learn more about syntax conventions.

Parameters

Name Type Required Description
regex string ✔️ The string or regular expression to be trimmed from the beginning of source.
source string ✔️ The source string from which to trim regex.

Returns

source after trimming match of regex found in the beginning of source.

Examples

Trim specific substring

The following example trims substring from the start of string_to_trim.

let string_to_trim = @"https://bing.com";
let substring = "https://";
print string_to_trim = string_to_trim,trimmed_string = trim_start(substring,string_to_trim)

Output

string_to_trim trimmed_string
https://bing.com bing.com

Trim non-alphanumeric characters

The following example trims all non-word characters from the beginning of the string.

range x from 1 to 5 step 1
| project str = strcat("-  ","Te st",x,@"// $")
| extend trimmed_str = trim_start(@"[^\w]+",str)

Output

str trimmed_str
- Te st1// $ Te st1// $
- Te st2// $ Te st2// $
- Te st3// $ Te st3// $
- Te st4// $ Te st4// $
- Te st5// $ Te st5// $

Trim whitespace

The following example trims all spaces from the start of the string.

let string_to_trim = @"    Hello, world!    ";
let substring = @"\s+";
print
    string_to_trim = string_to_trim,
    trimmed_start = trim_start(substring, string_to_trim)

Output

string_to_trim trimmed_start
Hello, world! Hello, world!