---
title: fmt.Warnf
description: Log a WARNING from a template.
categories: []
keywords: []
action:
  aliases: [warnf]
  related:
    - functions/fmt/Errorf
    - functions/fmt/Erroridf
  returnType: string
  signatures: ['fmt.Warnf FORMAT [INPUT]']
aliases: [/functions/warnf]
---

{{% include "functions/fmt/_common/fmt-layout.md" %}}

The `warnf` function evaluates the format string, then prints the result to the WARNING log. Hugo prints each unique message once to avoid flooding the log with duplicate warnings.

```go-html-template
{{ warnf "The %q shortcode was unable to find %s. See %s" .Name $file .Position }}
```