Content-type: text/html Man page of clock_gettime

clock_gettime

Section: C Library Functions (3)
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NAME

clock_gettime, clock_settime - Get or set the time for the specified clock (P1003.1b)  

SYNOPSIS

#include <time.h>

int clock_gettime (
clockid_t clock_id,
struct timespec *tp);

int clock_settime (
clockid_t clock_id,
const struct timespec *tp);  

PARAMETERS

clock_id
The clock type used to obtain the time for the clock that is set. The CLOCK_REALTIME clock is supported and represents the TIME-OF-DAY clock for the system.
*tp
A pointer to a timespec data structure.
 

DESCRIPTION

The clock_gettime function returns the current time (in seconds and nanoseconds) for the specified clock. The clock_settime function sets the specified clock. The CLOCK_REALTIME clock measures the amount of time elapsed since 00:00:00:00 January 1, 1970 Greenwich Mean Time (GMT), otherwise known as the Epoch. Time values that fall between two non-negative integer multiples of the resolution are truncated down to the smaller multiple of the resolution.

You must have superuser privileges to use the clock_settime function.  

RETURN VALUES

On a successful call to the clock_gettime or clock_settime functions, a value of 0 is returned.

On an unsuccessful call, a value of -1 is returned and errno is set to indicate that an error occurred.  

ERRORS

The clock_gettime, and clock_settime, functions fail under the following conditions:

[EINVAL]
The clock_id argument does not specify a known clock.

The value pointed to by the tp argument to the clock_settime function is outside the range for the given clock_id.

The tp argument specified a nanosecond value less than zero or greater than or equal to 1000 million.

[EPERM]
The requesting process does not have the appropriate privilege to set the specified clock.
 

RELATED INFORMATION

Functions: time(1), clock_getres(3), ctime(3), timer_gettime(3) delim off


 

Index

NAME
SYNOPSIS
PARAMETERS
DESCRIPTION
RETURN VALUES
ERRORS
RELATED INFORMATION

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Time: 02:42:12 GMT, October 02, 2010