getclock(3) [osf1 man page]
getclock(3) Library Functions Manual getclock(3) NAME
getclock - Gets current value of system-wide clock. LIBRARY
Standard C Library (libc.a) SYNOPSIS
#include <sys/timers.h> int getclock( int clktyp, struct timespec *tp) ; PARAMETERS
Identifies a system-wide clock. Points to a timespec structure space where the current value of the system-wide clock is stored. DESCRIPTION
The getclock() function sets the current value of the clock specified by clktyp into the location pointed to by the tp parameter. The clktyp parameter is given as a symbolic constant name, as defined in the sys/timers.h include file. Only the TIMEOFDAY symbolic con- stant, which specifies the normal time-of-day clock to access for system-wide time, is supported. For the clock specified by TIMEOFDAY, the value returned by this function is the elapsed time since the epoch. The epoch is referenced to 00:00:00 CUT (Coordinated Universal Time) 1 Jan 1970. The getclock() function returns a timespec structure, which is defined in the sys/timers.h header file. It has the following members: time_t tv_sec Elapsed time in seconds since the epoch long tv_nsec Elapsed time as a fraction of a second since the epoch (expressed in nanoseconds) The time interval expressed by the members of this structure is ((tv_sec * 10^9) + (tv_nsec)) nanoseconds. NOTES
Trial use RETURN VALUES
Upon successful completion, the getclock() function returns a value of 0 (zero). Otherwise, getclock() returns a value of -1 and sets errno to indicate the error. ERRORS
If the getclock() function fails, errno is to one of the following values: The clktyp parameter does not specify a known system-wide clock. An error occurred when the system-wide clock specified by the clktyp parameter was accessed. RELATED INFORMATION
Functions: gettimeofday(2), gettimer(3), setclock(3), time(3) delim off getclock(3)
Check Out this Related Man Page
setclock(3) Library Functions Manual setclock(3) NAME
setclock - Sets value of system-wide clock LIBRARY
Standard C Library (libc.a) SYNOPSIS
#include <sys/timers.h> int setclock( int clktyp, struct timespec *val) ; PARAMETERS
Specifies a system-wide clock whose symbolic name must be TIMEOFDAY. Points to the location where the value of the time to set into the clock specified by the clktyp parameter is stored. DESCRIPTION
The setclock() function sets a time value into the system-wide clock whose symbolic name is specified by the clktyp parameter, which must be TIMEOFDAY, defined in the sys/timers.h header file. The source of the current value of time set into the system-wide time-of-day clock by this function is stored in space reserved by a type timespec structure pointed to by the val parameter. This time information is the amount of time since the epoch. The epoch is referenced to 00:00:00 GMT (Greenwich Mean Time) 1 Jan 1970. The timespec structure, which is also defined in the sys/timers.h header file has the fol- lowing members: unsigned long tv_sec Time of day since the epoch in seconds. long tv_nsec Time of day fraction of a second (expressed in nanoseconds). NOTES
Trial use RETURN VALUES
Upon successful completion, the setclock() function returns a value of 0 (zero). Otherwise, a value of -1 is returned and errno is set to indicate the error. ERRORS
If the setclock() function fails, errno may be set to one of the following values: The clktyp parameter does not specify a known system- wide clock, the information pointed to by the val parameter is outside the permissible range for the clock specified by the clktyp parame- ter, or a nanosecond value less than zero or greater than or equal to 1000 million is specified by the information pointed to by the val parameter. An error occurred while accessing the clock specified by the clktyp parameter. The requesting process does not have the appro- priate privilege to set the clock specified by the clktyp parameter. RELATED INFORMATION
Functions: getclock(3), gettimer(3), time(3) delim off setclock(3)