pmgetconfig(3) — Linux manual page
PMGETCONFIG(3) Library Functions Manual PMGETCONFIG(3)
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) 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.
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) - 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). Values for these variables may be obtained programmatically using the pmGetConfig(3) function.
SEE ALSO
PCPIntro(1), pmconfig(1), pmGetVersion(3), exit(2), PMAPI(3), getenv(3), setenv(3), pcp.conf(5), pcp.env(5) and environ(7).
COLOPHON
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 pcp@groups.io. This page was obtained from the project's upstream Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on 2024-06-14. (At that time, the date of the most recent commit that was found in the repository was 2024-06-14.) 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 man-pages@man7.org Performance Co-Pilot PCP PMGETCONFIG(3)
Pages that refer to this page: pmconfig(1), pcpintro(3), pmapi(3), pmda(3), pmdaopenlog(3), pmdatrace(3), pmdiscoverservices(3), pmgetarchiveend(3), pmgetarchivelabel(3), pmgetchildren(3), pmgetchildrenstatus(3), pmgetconfig(3), pmgetcontexthostname(3), pmgetindom(3), pmgetindomarchive(3), pmgetoptions(3), pmgetpmnslocation(3), pmgetusername(3), pmgetversion(3), pmidstr(3), pmindomstr(3), pmloadasciinamespace(3), pmloadnamespace(3), pmlocaltime(3), pmlookupdesc(3), pmlookupindom(3), pmlookupindomarchive(3), pmlookupindomtext(3), pmlookupname(3), pmlookuptext(3), pmnameall(3), pmnameid(3), pmnameindom(3), pmnameindomarchive(3), pmnewcontext(3), pmnewcontextzone(3), pmnewzone(3), pcp.conf(5), pcp.env(5), pmns(5)