gettimeofday, settimeofday, ftime, gettimeofday64, settimeofday64,
TIMEVAL32TO64, TIMEVAL64TO32 - Gets and sets
date and time and converts time between timeval and
timeval64
#include <sys/time.h>
int gettimeofday(
struct timeval *tp,
void *tzp ); #include <sys/timeb.h>
int ftime(
struct timeb *tp );
The following function declarations do not conform to current
standards and are supported only for backward compatibility:
#include <sys/time.h>
int gettimeofday(
struct timeval *tp,
struct timezone *tzp ); int settimeofday(
struct timeval *tp,
struct timezone *tzp );
The following data type, function declarations, and macros
are Tru64 UNIX extensions and do not conform to current
standards. These features are provided to support the
time64_t data type and are accessible only when the
_TIME64_T feature macro is defined during compilation.
#include <sys/time.h>
struct timeval64 {
time64_t tv_sec; /* seconds */
int tv_usec; /* microseconds */ };
int gettimeofday64(
struct timeval64 *tp64,
void *tzp ); void TIMEVAL32TO64(
tv32, tv64 ); int TIMEVAL64TO32(
tv64, tv32 );
The following function declarations correspond to their
non-standard counterparts above, using timeval64 in place
of timeval: int gettimeofday64(
struct timeval64 *tp64,
struct timezone *tzp ); int settimeofday64(
struct timeval64 *tp64,
struct timezone *tzp );
Standard C Library (libc)
Interfaces documented on this reference page conform to
industry standards as follows:
gettimeofday(), ftime(): XPG4-UNIX
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
For gettimeofday() and settimeofday(), points to a timeval
structure, defined in the <sys/time.h> file.
For ftime(), points to a timeb structure, defined
in the <sys/timeb.h> file. [Tru64 UNIX] For the
backward-compatible versions of gettimeofday() and
settimeofday(), points to a timezone structure,
defined in the <sys/time.h> file. For gettimeofday64()
and settimeofday64(), points to a timeval64
structure, defined in the <sys/time.h> system
header file and described below. Refers to a variable
of type timeval. Refers to a variable of type
timeval64.
The gettimeofday(), ftime(), and settimeofday() functions
get and set the time and timezone information stored in
the kernel.
The gettimeofday() function gets the current time,
expressed in seconds and microseconds since midnight (0
hour), January 1, 1970 UTC (Coordinated Universal Time,
formerly Greenwich Mean Time or GMT), and stores it in the
timeval structure pointed to by tp.
The ftime() function sets the time and millitm members of
the timeb structure pointed to by tp to contain the seconds
and milliseconds portions, respectively, of the current
time in seconds since midnight (0 hour), January 1,
1970 UTC.
See the NOTES section for information on the backward-compatible
versions of gettimeofday() and settimeofday().
See the timezone(3) reference page for information on
timezone handling on Tru64 UNIX systems.
The timeval64 struct is identical to the timeval struct
defined in the <sys/time.h> system header file except that
the tv_sec (seconds) field is of type time64_t. The
time64_t data type is described in the time(3) reference
page. The timeval64 struct is provided to allow handling
of larger time values using the time64_t data type and is
only available when the _TIME64_T feature macro is defined
during compilation.
The gettimeofday64() and settimeofday64() functions work
exactly as the gettimeofday() and settimeofday() functions
(respectively), but use the larger timeval64 struct (referenced
by the tp64 pointer) instead of timeval. The current
system time setting limits (Jan 1 00:00:00 GMT 1970
through Jan 19 03:14:07 GMT 2038) are not changed by these
function or the timeval64 struct. These function declarations
are only available when the _TIME64_T feature macro
is defined during compilation.
The TIMEVAL32TO64() and TIMEVAL64TO32() macros are provided
to assist developers converting between values of
type timeval and values of type timeval64. The
TIMEVAL32TO64() macro converts the values contained in the
tv32 struct to values corresponding to timeval64 struct
members, storing the results in tv64 and performing signextension
on the tv_sec (seconds) field as appropriate.
The TIMEVAL64TO32() macro attempts to convert the values
contained in the timeval64 struct tv64 to values corresponding
to timeval struct members, storing the results in
tv32. If the value of the tv_sec (seconds) field of tv64
overflows the size of a time_t, the value of the
TIMEVAL64TO32() macro will be 1 and the values contained
in tv32 are undefined. Otherwise, the value of the
TIMEVAL64TO32() macro will be 0 and tv32 will contain the
converted values from tv64. These conversion macros are
only available when the _TIME64_T feature macro is defined
during compilation.
The following information applies only to the backwardcompatible
versions of the gettimeofday() and settimeofday()
functions.
[Tru64 UNIX] The timezone structure that is returned for
the gettimeofday() call is set at boot time by the
/sbin/init.d/settime script. The tz_minuteswest field of
the structure is set to your local time zone. This field
is set only for backward compatibility with older applications
that may use the gettimeofday() call for timezone
information. The tz_dsttime field is set to zero because
this field is obsolete.
[Tru64 UNIX] On SVID2-compatible systems, local timezone
information is maintained in the kernel, although the
information is not as accurate or as complete as the
information that can be maintained at user level. On
these systems, you can use the tzp parameter with gettimeofday()
and settimeofday() to get and set timezone information
in addition to the time. The tzp parameter returns
a pointer to a timezone structure that contains the local
timezone expressed in minutes of time westward from Greenwich
and a flag that, when nonzero, indicates that daylight
savings time applies locally during some part of the
year. Note that, if the tzp parameter is set to NULL,
timezone information is not returned or set.
[Tru64 UNIX] A process must have the sysattr effective
privilege to use settimeofday().
The above notes also pertain to the non-standard versions
of gettimeofday64() and settimeofday64() as well.
Upon successful completion, a value of 0 (zero) is
returned from gettimeofday(), settimeofday(), gettimeofday64(),
and settimeofday64(). Otherwise, -1 is returned
and errno is set to indicate the error.
If the gettimeofday(), settimeofday(), gettimeofday64(),
or settimeofday64() functions fail, errno may be set to
the following values: [Tru64 UNIX] A parameter points to
an invalid address. [Tru64 UNIX] The process's effective
user ID does not have the sysattr effective privilege,
which is required for using settimeofday() and settimeofday64().
Commands: date(1), zdump(8), zic(8)
Functions: adjtime(2), ctime(3), getclock(3), gettimer(3), setclock(3), strftime(3), timezone(3), time(3)
Files: tzfile(4)
Standards: standards(5)
gettimeofday(2)
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