---
name: "function::substr"
section: "3stap"
platform: "linux"
package: "systemtap-doc"
version: "5.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/function::substr"
---

# function::substr(3stap)

Returns a substring

## NAME

function::substr - Returns a substring

## SYNOPSIS

```
    substr:string(str:string,start:long,length:long)
```

## ARGUMENTS

*str*

the string to take a substring from

*start*

starting position of the extracted string (first character is 0)

*length*

length of string to return

## DESCRIPTION

Returns the substring of the given string at the given start position with the given length (or smaller if the length of the original string is less than start + length, or length is bigger than MAXSTRINGLEN).

## SEE ALSO0

[*tapset::string*(3stap)](/tapset::string/3stap.md)