NAME

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

C SYNOPSIS

       #include <pcp/pmapi.h>
       char *pmGetConfig(const char *variable);
       char *pmGetOptionalConfig(const char *variable);

       #include <pcp/impl.h>
       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 putenv(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  internal  __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(3C),  putenv(3C),  pcp.conf(5),
       pcp.env(5) and environ(7).

Performance Co-Pilot                                   PCP                                        PMGETCONFIG(3)