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.