FUNCTION::USER\_STRIN(3stap) String and data retrieving fun FUNCTION::USER\_STRIN(3stap)

# [NAME](#NAME)

function::user\_string\_n\_warn - Retrieves string from user space

# [SYNOPSIS](#SYNOPSIS)

```
1) user_string_n_warn:string(addr:long,n:long)
```

```
2) user_string_n_warn:string(addr:long,n:long,warn_msg:string)
```

# [ARGUMENTS](#ARGUMENTS)

*addr*

the user space address to retrieve the string from

*n*

the maximum length of the string (if not null terminated)

*warn\_msg*

the warning message to return when data isn't available

# [DESCRIPTION](#DESCRIPTION)

1\) Returns up to n characters of a C string from a given user space memory address. Reports“<unknown>” on the rare cases when userspace data is not accessible and warns (but does not abort) about the failure.

2\) Returns up to n characters of a C string from a given user space memory address. Reports the given warning message on the rare cases when userspace data is not accessible and warns (but does not abort) about the failure.

# [SEE ALSO0](#SEE_ALSO0)

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

September 2026 SystemTap Tapset Reference Ver

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