FUNCTION::SUBSTR(3stap) A collection of standard strin FUNCTION::SUBSTR(3stap)

# [NAME](#NAME)

function::substr - Returns a substring

# [SYNOPSIS](#SYNOPSIS)

```


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

# [ARGUMENTS](#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](#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](#SEE_ALSO0)

[*tapset::string*(3stap)](/man/enterprise-packages/systemtap/tapset::string.3stap)

September 2026 SystemTap Tapset Reference Ver

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Document: function::substr(3stap) from systemtap 5.6-r0 (Chainguard OS)
Source: https://sourceware.org/git/systemtap.git