time
—
get time of day
Standard C Library (libc, -lc)
#include
<time.h>
time_t
time
(
time_t
*tloc);
The
time
() function returns the value of time
in seconds since 0 hours, 0 minutes, 0 seconds, January 1, 1970, Coordinated
Universal Time. If an error occurs,
time
()
returns the value (
time_t)-1.
The return value is also stored in
*tloc, provided that
tloc is non-null.
The
time
() function may fail for any of the
reasons described in
gettimeofday(2).
clock_gettime(2),
gettimeofday(2),
ctime(3)
The
time
function conforms to
IEEE Std 1003.1-2001
(“POSIX.1”).
A
time
() function appeared in
Version 6 AT&T UNIX.
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
*tloc in the error
case.