---
name: "pmDerivedErrStr"
section: "3"
platform: "linux"
package: "pcp"
version: "7.2.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pmDerivedErrStr"
---

# pmDerivedErrStr(3)

return error message from failure to parse derived metric definition

## NAME

**pmDerivedErrStr** - return error message from failure to parse derived metric definition

## C SYNOPSIS

**#include \<pcp/pmapi.h\>**

**char \*pmDerivedErrStr(void);**

**cc ... -lpcp**

## DESCRIPTION

When [**pmRegisterDerived**(3)](/pmRegisterDerived/3.md) is called to add a new derived metric definition and an error occurs, **pmDerivedErrStr** may be called to return the associated error message.

The **pmRegisterDerivedMetric** interface provides a convenience wrapper around both **pmRegisterDerived** and **pmDerivedErrStr**.

## SEE ALSO

[**PCPIntro**(1)](/PCPIntro/1.md), [**PMAPI**(3)](/PMAPI/3.md) and [**pmRegisterDerived**(3)](/pmRegisterDerived/3.md).