coreutils/lib/gettimeofday.c
Jim Meyering d2be1268c4 Fix a problem seen only on nonconforming systems whereby ls.c's
use of localtime, and then of gettimeofday would cause trouble:
the localtime call used to initialize rpl_gettimeofday's save
mechanism would clobber ls's current local time information so
that in any long listing the first file would always be listed
with date 1970-01-01.  Analysis by Volker Borchert.

(localtime): Undefine.
(rpl_localtime): New function.
2002-05-27 16:42:55 +00:00

87 lines
2.4 KiB
C

/* Work around the bug in some systems whereby gettimeofday clobbers the
static buffer that localtime uses for it's return value. The gettimeofday
function from Mac OS X 10.0.4, i.e. Darwin 1.3.7 has this problem.
Copyright (C) 2001, 2002 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* written by Jim Meyering */
#include <config.h>
/* Disable the definitions of gettimeofday and localtime (from config.h)
so we can use the library versions here. */
#undef gettimeofday
#undef localtime
#include <sys/types.h>
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#include <stdlib.h>
static struct tm *localtime_buffer_addr;
/* This is a wrapper for localtime. It is used only on systems for which
gettimeofday clobbers the static buffer used for localtime's result.
On the first call, record the address of the static buffer that
localtime uses for its result. */
struct tm *
rpl_localtime (const time_t *timep)
{
struct tm *tm = localtime (timep);
if (! localtime_buffer_addr)
localtime_buffer_addr = tm;
return tm;
}
/* This is a wrapper for gettimeofday. It is used only on systems for which
gettimeofday clobbers the static buffer used for localtime's result.
Save and restore the contents of the buffer used for localtime's result
around the call to gettimeofday. */
int
rpl_gettimeofday (struct timeval *tv, struct timezone *tz)
{
struct tm save;
int result;
if (! localtime_buffer_addr)
{
time_t t = 0;
localtime_buffer_addr = localtime (&t);
}
save = *localtime_buffer_addr;
result = gettimeofday (tv, tz);
*localtime_buffer_addr = save;
return result;
}