time(3)time(3)NAME
time, time64, TIMET32TO64, TIMET64TO32 - Get time, converts time
between time_t and time64_t
SYNOPSIS
#include <time.h>
time_t time(
time_t *tloc );
The following data type, function declaration 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 <time.h>
typedef long time64_t;
time64_t time64(
time64_t *tloc64 ); void TIMET32TO64(
t32, t64 ); int TIMET64TO32(
t64, t32 );
LIBRARY
Standard C Library (libc)
PARAMETERS
Points to the location where the return value of type time_t is stored.
When this parameter is a null pointer, no value is stored. Points to
the location where the return value of type time64_t is stored. When
this parameter is a null pointer, no value is stored. Refers to a
variable of type time_t. Refers to a variable of type time64_t.
DESCRIPTION
The time() function returns the time in seconds since the Epoch. The
Epoch is referenced to 00:00:00 UTC (Coordinated Universal Time) 1 Jan
1970.
The time64_t data type is a 64-bit signed value which, like the 32-bit
time_t data type, is defined as the “time in seconds since the Epoch.”
It is provided for storage and manipulation of times beyond the range
of a 32-bit time_t (Dec 13 20:45:52 GMT 1901 through Jan 19 03:14:07
GMT 2038). This data type is only available when the _TIME64_T feature
macro is defined during compilation.
The time64() function works exactly as the time() function, but uses
the larger time64_t type (referenced by the tloc64 pointer) instead of
time_t. 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 this function or
the time64_t data type. This function declaration is only available
when the _TIME64_T feature macro is defined during compilation.
The TIMET32TO64() and TIMET64TO32() macros are provided to assist
developers converting between values of type time_t and values of type
time64_t. The TIMET32TO64() macro converts the value contained in t32
to a value of type time64_t and stores the result in t64, performing
sign-extension as appropriate. The TIMET64TO32() macro attempts to
convert the value contained in t64 to a value of type time_t, storing
the result in t32. If the value of t64 overflows the size of a time_t,
the value of the TIMET64TO32() macro will be 1 and the value of t32 is
undefined. Otherwise, the value of the TIMET64TO32() macro will be 0
and t32 will contain the converted value from t64. These conversion
macros are only available when the _TIME64_T feature macro is defined
during compilation.
RETURN VALUES
Upon successful completion, the time() function returns the value of
time in seconds since the Epoch. Otherwise, the value (time_t)-1 is
returned.
Upon successful completion, the time64() function returns the value of
time in seconds since the Epoch. Otherwise, the value (time64_t)-1 is
returned.
SEE ALSO
Functions: gettimeofday(2), clock(3), ctime(3), difftime(3), stime(3),
strftime(3), strptime(3)
Standards: standards(5)time(3)