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) 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).
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) 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.
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) - 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
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). Values for these
variables may be obtained programmatically using the pmGetConfig(3)
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at ⟨http://www.pcp.io/⟩.
If you have a bug report for this manual page, send it to
email@example.com. This page was obtained from the project's upstream
Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on
2020-06-09. (At that time, the date of the most recent commit that
was found in the repository was 2020-06-09.) If you discover any
rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
Performance Co-Pilot PCP PMGETCONFIG(3)