Convert tm structure to timeval structure
#include <pcp/pmapi.h>
#include <pcp/impl.h>
int __pmConvertTime(struct tm *tmin, struct timeval *origin, struct timeval *rslt);
cc ... -lpcp
__pmConvertTime accepts a tm structure that has been filled in by __pmParseCtime(3) and a reference time point origin, and fills in the given rslt structure with the time the user meant when he specified a partial ctime or positive or negative time interval.
Typically, the argument origin is the start time for a PCP archive log, unless the user specified a negative interval offset, in which case it is the end time of the log.
__pmConvertTime returns 0 if successful. It returns -1 and writes an error message to stderr, if an error is detected.
Use pmNewZone(3), pmNewContextZone(3) or pmUseZone(3) to establish a new current timezone that will effect __pmConvertTime.