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 timeval *logStart, const struct timeval *logEnd, struct timeval *rsltStart,
               struct timeval *rsltEnd, struct timeval *rsltOffset, char **errMsg);

       cc ... -lpcp

DESCRIPTION

       pmParseTimeWindow is designed to encapsulate the interpretation of the -S, -T, -A and -O command line op‐
       tions used by Performance Co-Pilot (PCP) applications to define a time window of interest.  The time win‐
       dow is defined by a start time and an end time that constrains the time interval during which the PCP ap‐
       plication  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 expects 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 archive logs as the source of performance metrics, you also need
       to supply the time of the first archive log entry as logStart, and the time of the last archive log entry
       as logEnd.  See pmGetArchiveLabel(3) and pmGetArchiveEnd(3) for how to obtain values for these times.

       If the application is manipulating multiple concurrent archive logs, then the caller must resolve how the
       default time window is to be defined (the union of the time intervals in all archive logs is a likely in‐
       terpretation).

       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
       INT_MAX.

       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 pmParseTimeWindow.  See pmUseZone(3) and friends for information on how this is
       done.

DIAGNOSTICS

       If the conversion is successful, pmParseTimeWindow returns 1 and fills in rsltStart, rsltEnd and rsltOff‐
       set  with  the start, end, and offset times for the time window defined by the input parameters.  The er‐
       rMsg parameter is not changed when pmParseTimeWindow returns 1.

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

       If the argument strings could not be parsed, pmParseTimeWindow returns -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).

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)