FUNCTION::WARN(3stap) Logging Tapset FUNCTION::WARN(3stap)

# [NAME](#NAME)

function::warn - Send a line to the warning stream

# [SYNOPSIS](#SYNOPSIS)

```


    warn(msg:string)
```

# [ARGUMENTS](#ARGUMENTS)

*msg*

The formatted message string

# [DESCRIPTION](#DESCRIPTION)

This function sends a warning message immediately to staprun. It is also sent over the bulk transport (relayfs) if it is being used. If the last characater is not a newline, the one is added.

# [SEE ALSO0](#SEE_ALSO0)

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

September 2026 SystemTap Tapset Reference Ver

---

Document: function::warn(3stap) from systemtap 5.6-r1 (Chainguard OS)
Source: https://sourceware.org/git/systemtap.git