NAME

       pmParseTimeWindow - parse time window command line arguments

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmParseTimeWindow(const char *swStart, const char *swEnd, const char *swAlign, const char *swOffset,
                             const struct timespec *logStart, const struct timespec *logEnd,
                             struct timespec *rsltStart, struct timespec *rsltEnd, struct timespec *rsltOffset,
                             char **errMsg);

       cc ... -lpcp

DESCRIPTION

       pmParseTimeWindow  are  designed  to encapsulate the interpretation of the -S, -T, -A and -O command line
       options used by Performance Co-Pilot (PCP) applications to define a time window of  interest.   The  time
       window  is defined by a start time and an end time that constrains the time interval during which the PCP
       application will retrieve and display performance metrics.  In the absence of the -O and  -A  options  to
       specify  an  initial sample time origin and time alignment (see below), the PCP application will retrieve
       the first sample at the start of the time window.

       The syntax and meaning of the various argument formats for these options is described in PCPIntro(1).

USAGE

       pmParseTimeWindow expect to be called with the argument of the -S option as swStart, the argument of  the
       -T option as swEnd, the argument of the -A option as swAlign, and the argument of the -O option as swOff‐
       set.   Any  or all of these parameters may be NULL to indicate that the corresponding command line option
       was not present.

       If the application is using a set of PCP archives as the source of performance metrics, you also need  to
       supply the time of the first archive entry as logStart, and the time of the last archive entry as logEnd.
       See pmGetArchiveLabel(3) and pmGetArchiveEnd(3) for how to obtain values for these times.

       If the application is manipulating multiple concurrent archives, then the caller must resolve how the de‐
       fault time window is to be defined (the union of the time intervals in all archives is a likely interpre‐
       tation).

       If  the  application  is  using a live feed of performance data, logStart should be the current time (but
       could be aligned on the next second for example), while logEnd should have its tv_sec  component  set  to
       PM_MAX_TIME_T.

       The rsltStart, rsltEnd and rsltOffset structures must be allocated before calling pmParseTimeWindow.

       You  also need to set the current PCP reporting time zone to correctly reflect the -z and -Z command line
       parameters before calling these routines.  See pmUseZone(3) and friends for information on  how  this  is
       done.

DIAGNOSTICS

       If the conversion is successful, pmParseTimeWindow return 1 and fill in rsltStart, rsltEnd and rsltOffset
       with  the  start,  end, and offset times for the time window defined by the input parameters.  The errMsg
       parameter is not changed when either pmParseTimeWindow returns 1.

       If the conversion is successful, but the requested alignment could not be performed (e.g. the set of  PCP
       archives  is too short) the alignment is ignored, rsltStart, rsltEnd and rsltOffset are filled in and pm‐
       ParseTimeWindow return 0.  In this case, errMsg will point to a warning message in a dynamically allocat‐
       ed buffer.  The caller is responsible for releasing the buffer by calling free(3).

       If the argument strings could not be parsed, pmParseTimeWindow return -1.   In  this  case,  errMsg  will
       point to an error message in a dynamically allocated buffer.  The caller is responsible for releasing the
       buffer by calling free(3).

COMPATIBILITY

       Prior  to  PCP 7.0 and libpcp.so.4 the logStart, logEnd, rsltStart, rsltEnd and rsltOffset arguments were
       struct timeval.  To support PMAPI transition, the old interface and semantics can be used if applications
       are linked with libpcp.so.3 or recompiled with -DPMAPI_VERSION=2.

       For a time in PCP 6.x there was a routine with the same semantics as the current pmParseTimeWindow called
       pmParseHighResTimeWindow although this is now deprecated and  compile-time  support  for  pmParseHighRes‐
       TimeWindow will be removed in a future release.

SEE ALSO

       free(3),  PMAPI(3),  pmGetArchiveEnd(3),  pmGetArchiveLabel(3), pmNewContextZone(3), pmNewZone(3), pmPar‐
       seInterval(3) and pmUseZone(3).

Performance Co-Pilot                                   PCP                                  PMPARSETIMEWINDOW(3)