time

NAME

<span class="Nm" id="time">time</span>

INTERFACE

#include <time.h> time_t time ( time_t *tloc )

DESCRIPTION

The time function returns the value of time in seconds since 0 hours, 0 minutes, 0 seconds, January 1, 1970, Coordinated Universal Time, without including leap seconds. If an error occurs, time returns the value <span class="Vt">time_t</span> - 1.

The return value is also stored in <span class="Va">* tloc</span>, provided that <span class="Va">tloc</span> is non-null.

#include <stdio.h>
#include <time.h>

int main ()
{
  printf ("%ld hours since January 1, 1970\n", time(0)/3600);  
  return 0;
}

339479 hours since January 1, 1970

ERRORS

The time function may fail for any of the reasons described in gettimeofday.

SEE ALSO

ctime

STANDARDS

The time function conforms to IEEE Std 1003.1-2001 ("POSIX.1").

BUGS

Neither ISO/IEC 9899:1999 ("ISO C99") nor IEEE Std 1003.1-2001 ("POSIX.1") requires time to set errno on failure; thus, it is impossible for an application to distinguish the valid time value -1 (representing the last UTC second of 1969) from the error return value.

Systems conforming to earlier versions of the C and POSIX standards (including older versions of FreeBSD) did not set <span class="Va">* tloc</span> in the error case.

HISTORY

A time function appeared in Version 6 AT&T UNIX.