freebsd-skq/contrib/tar/lib/utime.c

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/* Copyright (C) 1998, 2001 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. */
/* derived from a function in touch.c */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#undef utime
#include <sys/types.h>
#ifdef HAVE_UTIME_H
# include <utime.h>
#endif
#include "full-write.h"
#include "safe-read.h"
/* Some systems (even some that do have <utime.h>) don't declare this
structure anywhere. */
#ifndef HAVE_STRUCT_UTIMBUF
struct utimbuf
{
long actime;
long modtime;
};
#endif
/* Emulate utime (file, NULL) for systems (like 4.3BSD) that do not
interpret it to set the access and modification times of FILE to
the current time. Return 0 if successful, -1 if not. */
static int
utime_null (const char *file)
{
#if HAVE_UTIMES_NULL
return utimes (file, 0);
#else
int fd;
char c;
int status = 0;
struct stat sb;
fd = open (file, O_RDWR);
if (fd < 0
|| fstat (fd, &sb) < 0
|| safe_read (fd, &c, sizeof c) < 0
|| lseek (fd, (off_t) 0, SEEK_SET) < 0
|| full_write (fd, &c, sizeof c) != sizeof c
/* Maybe do this -- it's necessary on SunOS4.1.3 with some combination
of patches, but that system doesn't use this code: it has utimes.
|| fsync (fd) < 0
*/
|| ftruncate (fd, st.st_size) < 0
|| close (fd) < 0)
status = -1;
return status;
#endif
}
int
rpl_utime (const char *file, const struct utimbuf *times)
{
if (times)
return utime (file, times);
return utime_null (file);
}