NAME

time, time64, TIMET32TO64, TIMET64TO32 − Gets time, converts time between time_t and time64_t

LIBRARY

Standard C Library (libc.so, libc.a)

SYNOPSIS

#include <time.h>

time_t time(
        time_t ∗tloc);

The following data type, function declaration and macros are Compaq 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)

PARAMETERS

tlocPoints to the location where the return value of type time_t is stored. When this parameter is a null pointer, no value is stored. 

tloc64Points to the location where the return value of type time64_t is stored. When this parameter is a null pointer, no value is stored. 

t32Refers to a variable of type time_t. 

t64Refers 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 CUT (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. 

RELATED INFORMATION

Functions: gettimeofday(2), clock(3), ctime(3), difftime(3), stime(3), strftime(3), strptime(3)

Standards: standards(5)