возвращаемые значения для переменных конфигурации performance Co-Pilot (return values for performance Co-Pilot configuration variables)
Имя (Name)
pmGetConfig, pmGetOptionalConfig, pmGetAPIConfig - return values
for Performance Co-Pilot configuration variables
Синопсис C (C Synopsis)
#include <pcp/pmapi.h>
char *pmGetConfig(const char *variable);
char *pmGetOptionalConfig(const char *variable);
char *pmGetAPIConfig(const char *feature);
cc ... -lpcp
Описание (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.
Возвращаемое значение (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.
Окружение PCP (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.
Смотри также (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).
