(BSD System Compatibility)
gettimeofday(3bsd)
gettimeofday, settimeofday --
(BSD) get or set the date and time
Synopsis
/usr/ucb/cc [flag . . . ] file . . .
#include <sys/time.h>
int gettimeofday(struct timeval *tp, struct timezone *tzp);
int settimeofday(struct timeval *tp, struct timezone *tzp);
Description
The system's notion of the current Greenwich time
is obtained with the
gettimeofday
call, and set with the
settimeofday
call.
The current time is expressed in elapsed seconds and microseconds
since 00:00
GMT,
January 1, 1970 (zero hour).
The resolution of the system
clock is hardware dependent; the time may be updated continuously,
or in ``ticks.''
tp
points to a
timeval
structure, which includes the following members:
long tv_sec; /* seconds since Jan. 1, 1970 */
long tv_usec; /* and microseconds */
If
tp
is a
NULL
pointer, the current time information is not returned or set.
tzp
is an obsolete pointer formerly used to get and set time zone information.
tzp
is now ignored.
Time zone information is now handled using the TZ
environment variable; see
timezone(4).
Only the privileged user may set the time of day.
Return values
A -1 return value indicates an error occurred; in this
case an error code is stored in the global variable
errno.
The following error codes may be set in
errno:
EINVAL-
tp
specifies an invalid time.
EPERM-
A user other than the privileged user attempted to set the time.
References
adjtime(2),
ctime(3C),
date(1),
gettimeofday(2),
timezone(4)
Notices
Time is never correct enough to believe the microsecond values.
tzp is ignored.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004