gen/FreeBSD/time.3

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  36 .\"     @(#)time.3      8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/gen/time.3,v 1.13 2004/07/02 19:07:30 ru Exp $
  38 .\"
  39 .Dd July 18, 2003
  40 .Dt TIME 3
  41 .Os
  42 .Sh NAME
  43 .Nm time
  44 .Nd get time of day
  45 .Sh LIBRARY
  46 .Lb libc
  47 .Sh SYNOPSIS
  48 .In time.h
  49 .Ft time_t
  50 .Fn time "time_t *tloc"
  51 .Sh DESCRIPTION
  52 The
  53 .Fn time
  54 function
  55 returns the value of time in seconds since 0 hours, 0 minutes,
  56 0 seconds, January 1, 1970, Coordinated Universal Time.
  57 If an error occurs,
  58 .Fn time
  59 returns the value
  60 .Po Vt time_t Pc Ns \-1 .
  61 .Pp
  62 The return value is also stored in
  63 .No \&* Ns Va tloc ,
  64 provided that
  65 .Va tloc
  66 is non-null.
  67 .Sh ERRORS
  68 The
  69 .Fn time
  70 function may fail for any of the reasons described in
  71 .Xr gettimeofday 2 .
  72 .Sh SEE ALSO
  73 .Xr gettimeofday 2 ,
  74 .Xr ctime 3
  75 .Sh STANDARDS
  76 The
  77 .Nm
  78 function conforms to
  79 .St -p1003.1-2001 .
  80 .Sh BUGS
  81 Neither
  82 .St -isoC-99
  83 nor
  84 .St -p1003.1-2001
  85 requires
  86 .Fn time
  87 to set
  88 .Va errno
  89 on failure; thus, it is impossible for an application to distinguish
  90 the valid time value \-1 (representing the last UTC second of 1969)
  91 from the error return value.
  92 .Pp
  93 Systems conforming to earlier versions of the C and
  94 .Tn POSIX
  95 standards (including older versions of
  96 .Fx )
  97 did not set
  98 .No \&* Ns Va tloc
  99 in the error case.
 100 .Sh HISTORY
 101 A
 102 .Fn time
 103 function appeared in
 104 .At v6 .