timespec_getres

 

C

Language

Headers

Type support

Program utilities

Variadic function support

Error handling

Dynamic memory management

Strings library

Algorithms

Numerics

Date and time utilities

Input/output support

Localization support

Concurrency support (C11)

Technical Specifications

Symbol index

 

Date and time utilities

Functions

Time manipulation

difftime

time

clock

timespec_get (C11)

timespec_getres (C23)

Format conversions

asctimeasctime_rasctime_s (C23)(C11)

ctimectime_rctime_s (C23)(C11)

strftime

wcsftime (C95)

gmtimegmtime_rgmtime_s (C23)(C11)

localtimelocaltime_rlocaltime_s (C23)(C11)

mktime

Constants

CLOCKS_PER_SEC

Types

tm

time_t

clock_t

timespec (C11)

 

Defined in header <time.h>
int timespec_getres( struct timespec *ts, int base );		(since C23)

If ts is non-null and base is supported by timespec_get, modifies *ts to hold the resolution of time provided by timespec_get for base. For each supported base, multiple calls to timespec_getres during the same program execution have identical results.

Parameters

ts	-	pointer to an object of type struct timespec
base	-	TIME_UTC or another nonzero integer value indicating the time base

Return value

The value of base if base is supported, zero otherwise.

Notes

The POSIX function clock_getres(clock_id, ts) may also be used to populate a timespec with the resolution of time identified by clock_id.

Example

Run this code

#include <stdio.h>
#include <time.h>
 
int main(void)
{
    char buff[128];
    struct timespec ts;
    const int res = timespec_getres(&ts, TIME_UTC);
    if (res == TIME_UTC) {
        struct tm timer;
        strftime(buff, sizeof buff, "%D %T", gmtime_r(&ts.tv_sec, &timer));
        printf("Time resolution info: %s.%09ld UTC\n", buff, ts.tv_nsec);
    } else {
        printf("TIME_UTC base is not supported.");
    }
}

Possible output:

Time resolution info: 01/01/70 00:00:00.000000001 UTC

See also

timespec (C11)	time in seconds and nanoseconds (struct)
timespec_get (C11)	returns the calendar time in seconds and nanoseconds based on a given time base (function)
time	returns the current calendar time of the system as time since epoch (function)