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

# pmGetConfig(3)

return values for Performance Co-Pilot configuration variables

## NAME

**pmGetConfig**, **pmGetOptionalConfig**, **pmGetAPIConfig** - return values for Performance Co-Pilot configuration variables

## C SYNOPSIS

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

**char \*pmGetConfig(const char \****variable***);**\
 **char \*pmGetOptionalConfig(const char \****variable***);**\
 **char \*pmGetAPIConfig(const char \****feature***);**

**cc ... -lpcp**

## DESCRIPTION

The **pmGetConfig** and **pmGetOptionalConfig** functions search for *variable* first in the environment and then, if not found, in the Performance Co-Pilot (PCP) configuration file and returns the string result. If *variable* is not already in the environment, it is added with a call to [**setenv**(3)](/setenv/3.md) before returning.

The **pmGetOptionalConfig** function allows for failures - either from *variable* not being set at all, or due to the configuration file being missing. **pmGetConfig** is less tolerant to a missing configuration file, which it treats as a critical PCP installation failure - see the \`\`RETURN VALUE'' section below for further details.

The default location of the PCP configuration file is **/etc/pcp.conf** but this may be changed by setting **PCP\_CONF** in the environment to a new location, as described in [**pcp.conf**(5)](/pcp.conf/5.md).

The **pmGetAPIConfig** function reports on features of the PCP library. It can be used to query support for multi-threading, security extensions, and other features.

The [**pmconfig**(1)](/pmconfig/1.md) utility provides command line access to both of these interfaces, and also provides a mechanism for listing all available **variables** and **features** that are valid arguments to these routines.

## RETURN VALUE

If *variable* is not found in either the environment or the PCP configuration file, or if the configuration file is inaccessible, then **pmGetOptionalConfig** returns NULL.

If *variable* is found in neither the environment nor the PCP configuration file, then **pmGetConfig** returns an empty string. If the PCP configuration file is not found then a fatal error message is printed and the process will [**exit**(2)](/exit/2.md) - although this sounds drastic, it is the only course of action available because the PCP configuration/installation is deemed fatally flawed.

The **pmGetAPIConfig** routine returns NULL on failure to lookup the requested *feature*. It does not modify the environment, and returns a pointer to a static read-only string.

The value returned by all of these routines is either a static pointer or pointer into the environment, and so changing it is a bad idea.

## PCP ENVIRONMENT

Environment variables with the prefix **PCP\_** are used to parameterize the file and directory names used by PCP. On each installation, the file */etc/pcp.conf* contains the local values for these variables. The **$PCP\_CONF** variable may be used to specify an alternative configuration file, as described in [**pcp.conf**(5)](/pcp.conf/5.md). Values for these variables may be obtained programmatically using the [**pmGetConfig**(3)](/pmGetConfig/3.md) function.

## SEE ALSO

[**PCPIntro**(1)](/PCPIntro/1.md), [**pmconfig**(1)](/pmconfig/1.md), [**pmGetVersion**(3)](/pmGetVersion/3.md), [**exit**(2)](/exit/2.md), [**PMAPI**(3)](/PMAPI/3.md), [**getenv**(3)](/getenv/3.md), [**setenv**(3)](/setenv/3.md), [**pcp.conf**(5)](/pcp.conf/5.md), [**pcp.env**(5)](/pcp.env/5.md) and [**environ**(7)](/environ/7.md).