2fe8fb192f
There is important information about booting non-ack images in docs/UPDATING. ack/aout-format images can't be built any more, and booting clang/ELF-format ones is a little different. Updating to the new boot monitor is recommended. Changes in this commit: . drop boot monitor -> allowing dropping ack support . facility to copy ELF boot files to /boot so that old boot monitor can still boot fairly easily, see UPDATING . no more ack-format libraries -> single-case libraries . some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases . drop several ack toolchain commands, but not all support commands (e.g. aal is gone but acksize is not yet). . a few libc files moved to netbsd libc dir . new /bin/date as minix date used code in libc/ . test compile fix . harmonize includes . /usr/lib is no longer special: without ack, /usr/lib plays no kind of special bootstrapping role any more and bootstrapping is done exclusively through packages, so releases depend even less on the state of the machine making them now. . rename nbsd_lib* to lib* . reduce mtree
156 lines
4.7 KiB
Groff
156 lines
4.7 KiB
Groff
.\" $NetBSD: gettimeofday.2,v 1.27 2010/05/18 07:14:18 jruoho Exp $
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.\"
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.\" Copyright (c) 1980, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)gettimeofday.2 8.2 (Berkeley) 5/26/95
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.\"
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.Dd May 18, 2010
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.Dt GETTIMEOFDAY 2
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.Os
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.Sh NAME
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.Nm gettimeofday ,
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.Nm settimeofday
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.Nd get/set date and time
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In sys/time.h
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.Ft int
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.Fn gettimeofday "struct timeval * restrict tp" "void * restrict tzp"
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.Ft int
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.Fn settimeofday "const struct timeval * restrict tp" "const void * restrict tzp"
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.Sh DESCRIPTION
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.Bf -symbolic
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Note: time zone information is no longer provided by this interface.
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See
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.Xr localtime 3
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for information on how to retrieve it.
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.Ef
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.Pp
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The system's notion of the current UTC time is obtained with the
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.Fn gettimeofday
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call, and set with the
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.Fn settimeofday
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call.
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The time is expressed in seconds and microseconds
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since midnight (0 hour), January 1, 1970.
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The resolution of the system clock is hardware dependent,
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and the time may be updated continuously or in
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.Dq ticks .
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.Pp
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If
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.Fa tp
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is NULL, the time will not be returned or set.
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Despite being declared
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.Fa void * ,
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the objects pointed to by
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.Fa tzp
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shall be of type
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.Fa struct timezone .
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.Pp
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The structures pointed to by
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.Fa tp
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and
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.Fa tzp
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are defined in
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.In sys/time.h .
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The first one is described in
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.Xr timeval 3
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and the latter legacy structure is defined as:
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.Bd -literal -offset indent
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struct timezone {
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int tz_minuteswest; /* of Greenwich */
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int tz_dsttime; /* type of dst correction to apply */
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};
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.Ed
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.Pp
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The
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.Fa timezone
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structure is provided only for source compatibility.
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It is ignored by
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.Fn settimeofday ,
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and
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.Fn gettimeofday
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will always return zeroes.
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.Pp
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If the calling user is not the super-user, then the
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.Fn settimeofday
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function in the standard C library will try to use the
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.Xr clockctl 4
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device if present, thus making possible for non privileged users to
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set the system time.
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If
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.Xr clockctl 4
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is not present or not accessible, then
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.Fn settimeofday
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reverts to the
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.Fn settimeofday
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system call, which is restricted to the super user.
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.\" XXX uncomment when/if this is put into place!
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.\" If the system is running in secure mode (see
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.\" .Xr init 8 ),
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.\" the time may only be advanced.
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.\" This limitation is imposed to prevent a malicious super user
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.\" from setting arbitrary time stamps on files.
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.\" The system time can still be adjusted backwards using the
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.\" .Xr adjtime 2
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.\" system call even when the system is secure.
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.Sh RETURN VALUES
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A return value 0 indicates that the call succeeded.
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A return value \-1 indicates an error occurred, and in this
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case an error code is stored into the global variable
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.Va errno .
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.Sh ERRORS
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The following error codes may be set in
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.Va errno :
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.Bl -tag -width Er
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.It Bq Er EFAULT
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An argument address referenced invalid memory.
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.It Bq Er EPERM
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A user other than the super user attempted to set the time, or the specified
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time was less than the current time, which was not permitted at the current
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security level.
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.El
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.Sh SEE ALSO
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.Xr date 1 ,
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.Xr adjtime 2 ,
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.Xr ctime 3 ,
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.Xr localtime 3 ,
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.Xr clockctl 4 ,
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.Xr timed 8
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.Sh HISTORY
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The
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.Fn gettimeofday
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function call appeared in
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.Bx 4.2 .
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The
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.Fa tzp
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argument was deprecated in
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.Bx 4.4
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(and many other systems).
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