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   pmgetarchiveend    ( 3 )

найти логический конец файла для набора архивных журналов (locate logical end of file for a set of archive logs)

Имя (Name)

pmGetArchiveEnd - locate logical end of file for a set of archive
       logs

Синопсис C (C Synopsis)

#include <pcp/pmapi.h>

int pmGetArchiveEnd(struct timeval *tvp);

cc ... -lpcp


Описание (Description)

Assuming the current PMAPI context is associated with a set of
       archive logs, pmGetArchiveEnd will attempt to find the logical
       end of file (after the last complete record in the set of
       archives), and return the last recorded timestamp via tvp.  This
       timestamp may be passed to pmSetMode(3) to reliably position the
       context at the last valid log record, e.g. in preparation for
       subsequent reading in reverse chronological order.

For archive logs that are not concurrently being written, the physical end of file and the logical end of file are co-incident. However if an archive log is being written by pmlogger(1) at the same time an application is trying to read the archive, the logical end of file may be before the physical end of file due to write buffering that is not aligned with the logical record boundaries.

pmGetArchiveEnd returns an error less than zero if the context is neither valid, nor associated with a set of archives, or the set of archives is seriously corrupted. Otherwise, the return value is 0 if there has been no change of state since the last call, or 1 if the logical end of file has advanced since the last call.

In the absence of an error, the result returned via tvp is well- defined.

pmGetArchiveEnd preserves the positioning state of the log file prior to this function call.


Диагностика (Diagnostic)

PM_ERR_NOCONTEXT
              the current PMAPI context is either invalid, or not
              associated with an set of archive logs

PM_ERR_LOGREC the set of archives is sufficiently damaged, that not a single valid record can be found


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)

PMAPI(3), pmFetch(3), pmFetchArchive(3), pmGetArchiveLabel(3),
       pmGetConfig(3), pmSetMode(3), pcp.conf(5) and pcp.env(5).