1PMGETARCHIVEEND(3)         Library Functions Manual         PMGETARCHIVEEND(3)
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NAME

6       pmGetArchiveEnd - locate logical end of file for an archive log
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C SYNOPSIS

9       #include <pcp/pmapi.h>
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11       int pmGetArchiveEnd(struct timeval *tvp);
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13       cc ... -lpcp
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DESCRIPTION

16       Assuming  the  current PMAPI context is associated with an archive log,
17       pmGetArchiveEnd will attempt to find the logical end of file (after the
18       last  complete  record  in  the  archive), and return the last recorded
19       timestamp via tvp.  This timestamp may be  passed  to  pmSetMode(3)  to
20       reliably  position  the  context  at the last valid log record, e.g. in
21       preparation for subsequent reading in reverse chronological order.
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23       For archive logs that are not concurrently being written, the  physical
24       end of file and the logical end of file are co-incident.  However if an
25       archive log is being written by pmlogger(1) at the same time an  appli‐
26       cation  is  trying  to read the archive, the logical end of file may be
27       before the physical end of file due to  write  buffering  that  is  not
28       aligned with the logical record boundaries.
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30       pmGetArchiveEnd  returns an error less than zero if the context is nei‐
31       ther valid, nor associated with an archive, or the archive is seriously
32       corrupted.   Otherwise,  the  return  value  is  0 if there has been no
33       change of state since the last call, or 1 if the logical  end  of  file
34       has advanced since the last call.
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36       In  the  absence  of  an  error,  the  result returned via tvp is well-
37       defined.
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39       pmGetArchiveEnd preserves the positioning state of the log  file  prior
40       to this function call.
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PCP ENVIRONMENT

43       Environment variables with the prefix PCP_ are used to parameterize the
44       file and directory names used by PCP.  On each installation,  the  file
45       /etc/pcp.conf  contains  the  local  values  for  these variables.  The
46       $PCP_CONF variable may be used to specify an alternative  configuration
47       file,  as  described in pcp.conf(4).  Values for these variables may be
48       obtained programatically using the pmGetConfig(3) function.
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SEE ALSO

51       PMAPI(3), pmFetch(3), pmFetchArchive(3),  pmGetArchiveLabel(3),  pmGet‐
52       Config(3), pmSetMode(3), pcp.conf(4) and pcp.env(4).
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DIAGNOSTICS

55       PM_ERR_NOCONTEXT
56              the  current  PMAPI context is either invalid, or not associated
57              with an archive log
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59       PM_ERR_LOGREC
60              the archive is sufficiently damaged, that  not  a  single  valid
61              record can be found
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