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

# [NAME](#NAME)

function::isinstr - Returns whether a string is a substring of another string

# [SYNOPSIS](#SYNOPSIS)

```


    isinstr:long(s1:string,s2:string)
```

# [ARGUMENTS](#ARGUMENTS)

*s1*

string to search in

*s2*

substring to find

# [DESCRIPTION](#DESCRIPTION)

This function returns 1 if string *s1* contains *s2*, otherwise zero.

# [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::isinstr(3stap) from systemtap 5.6-r0 (Chainguard OS)
Source: https://sourceware.org/git/systemtap.git