HP-UX Reference (11i v2 03/08) - 2 System Calls (vol 5)

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settimeofday(2) settimeofday(2)

NAME

settimeofday - set the date and time

SYNOPSIS

#include <sys/time.h>

int settimeofday struct timeval *tp, const struct timezone *tzp);

DESCRIPTION

The settimeofday()

function sets the current time, expressed as seconds and microseconds since

Epoch, and passed as the

timeval structure pointed to by tp .

The resolution of the system clock is one microsecond.

Security Restrictions

Only a user with appropriate privileges can set the time of day.

PARAMETERS

tp A pointer to a

timeval structure in which the current time is returned.

The

timeval structure includes the following members:

time_t tv_sec /* Seconds. */

long tv_usec /* Microseconds. */

tzp If this parameter is not a null pointer, it is interpreted as a pointer to a

timezone structure under

HP-UX. The

timezone structure has the following ﬁelds:

tz_minuteswest The number of minutes that the local time zone is west of Coordinated Universal

Time (UTC) or Epoch.

tz_dsttime A ﬂag that, if nonzero, indicates that Daylight Savings Time (DST) applies locally

during the appropriate part of the year.

RETURN VALUE

gettimeofday() returns the following values under HP-UX:

0 Successful completion.

-1 Failure. errno is set to indicate the error.

ERRORS

gettimeofday() fails, errno

is set to the following value under HP-UX:

[EFAULT] An argument address referenced invalid memory.

[EINVAL] The

tv_sec member of the tp parameter to settimeofday()

was less than zero

or greater than 2ˆ31.

[EPERM] A user lacking appropriate privileges attempted to set the time.

WARNINGS

Relying on a granularity of one microsecond may result in code that is not portable to other platforms.

AUTHOR

settimeofday() was developed by the University of California, Berkeley, and HP.