TIME(3) BSD Library Functions Manual TIME(3)
NAME
time — get time of day
LIBRARY
Standard C Library (libc, −lc)
SYNOPSIS
#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. 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.
ERRORS
The time() function may fail for any of the reasons described in gettimeofday(2).
SEE ALSO
clock_gettime(2), gettimeofday(2), ctime(3)
STANDARDS
The time function conforms to IEEE Std 1003.1-2001 (‘‘POSIX.1’’).
HISTORY
A time() function appeared in Version 6 AT&T UNIX.
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 *tloc in the error case.
BSD July 18, 2003 BSD