PMTIMESPECNOW(3)

NAME
pmtimespecNow, pmtimespecInc, pmtimespecDec, pmtimespecAdd, pmtimespecSub, pmtimespecToReal, pmtimespecFromReal, pmtimespecTotimeval, pmtimespecPrint, pmtimespecPrintInterval - helper routines for time stored as a struct timespec

C SYNOPSIS
#include <pcp/pmapi.h>

void pmtimespecNow(struct timespec *tp);
void pmtimespecInc(struct timespec *ap, const struct timespec *bp);
void pmtimespecDec(struct timespec *ap, const struct timespec *bp);
double pmtimespecAdd(const struct timespec *ap,
const struct timespec *bp);
double pmtimespecSub(const struct timespec *ap,
const struct timespec *bp);
double pmtimespecToReal(const struct timespec *tp);
void pmtimespecFromReal(double secs, struct timespec *tp);
void pmtimespecTotimeval(struct timespec *tsp, struct timeval *tvp);
void pmtimespecPrint(FILE *f, const struct timespec *tp);
void pmtimespecPrintInterval(FILE *f, const struct timespec *tp);

cc ... -lpcp

DESCRIPTION
pmtimespecNow is a platform-independent method that returns the current system time since the Epoch in tp.

pmtimespecInc adds the time in ap to the time in bp and stores the result in ap. Similarly pmtimespecDec subtracts the time in bp from the time in ap and stores the result in ap.

pmtimespecAdd (and pmtimespecSub) add (and subtract) times and return the result as a double value. The time in the ap argument is not changed.

pmtimespecToReal converts the time in tp to an equivalent double value. pmtimespecFromReal provides the reverse conversion, taking the time in secs and returning the equivalent time in tp.

pmtimespecTotimeval converts the struct timespec tsp into an equivalent struct timeval tvp (modulo nanosecond to microsecond truncation).

For pmtimespecAdd, pmtimespecSub, pmtimespecToReal and pmtimespecFromReal there is an issue of numerical precision. If the double result or operand has more than 6 decimal digits of precision in the seconds part of the value, then the fractional value is converted to microseconds before arithmetic computations, so the nanoseconds field is only accurate to 6 decimal digits in this case.

pmtimespecPrint prints the timestamp from tp on the stream f in the local time (as returned by pmLocaltime(3)) in the format HH:MM:SS.XXXXXXXXX.

pmtimespecPrintInterval prints the interval from tp on the stream f in a minimalist format [[HHh]MMm]SS[.XXXXXXXXX]s where the hours, minutes and nanoseconds are only reported if they are non-zero, and any trailing zeroes in the nanoseconds are omitted. For example if tp->tv_sec was 75 and tp->tv_nsec was 51000000 then the output would be 1h15.51s.

NOTES
For variants of these interfaces using microsecond precision and the timeval structure, refer to pmtimevalNow(3).

COMPATIBILITY
Prior to PCP 7.0 the routine pmtimespecPrint was called pmPrintHighResStamp. To support PMAPI transition, the old routine can still be used if applications are recompiled with -DPMAPI_VERSION=2.

pmPrintHighResStamp is now deprecated and compile-time support for this routine name will be removed in a future release.

SEE ALSO
PMAPI(3), pmLocaltime(3) and pmtimevalNow(3).