1/* Copyright (C) 1998, 2001, 2002, 2003, 2004, 2006 Free Software
2   Foundation, Inc.
3
4   This program is free software; you can redistribute it and/or modify it
5   under the terms of the GNU General Public License as published by the
6   Free Software Foundation; either version 2, or (at your option) any
7   later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program; if not, write to the Free Software Foundation,
16   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
17
18/* derived from a function in touch.c */
19
20#include <config.h>
21#undef utime
22
23#include <sys/types.h>
24
25#ifdef HAVE_UTIME_H
26# include <utime.h>
27#endif
28
29#if !HAVE_UTIMES_NULL
30# include <sys/stat.h>
31# include <fcntl.h>
32#endif
33
34#include <unistd.h>
35#include <errno.h>
36
37#include "full-write.h"
38#include "safe-read.h"
39
40/* Some systems (even some that do have <utime.h>) don't declare this
41   structure anywhere.  */
42#ifndef HAVE_STRUCT_UTIMBUF
43struct utimbuf
44{
45  long actime;
46  long modtime;
47};
48#endif
49
50/* The results of open() in this file are not used with fchdir,
51   therefore save some unnecessary work in fchdir.c.  */
52#undef open
53#undef close
54
55/* Emulate utime (file, NULL) for systems (like 4.3BSD) that do not
56   interpret it to set the access and modification times of FILE to
57   the current time.  Return 0 if successful, -1 if not. */
58
59static int
60utime_null (const char *file)
61{
62#if HAVE_UTIMES_NULL
63  return utimes (file, 0);
64#else
65  int fd;
66  char c;
67  int status = 0;
68  struct stat st;
69  int saved_errno = 0;
70
71  fd = open (file, O_RDWR);
72  if (fd < 0
73      || fstat (fd, &st) < 0
74      || safe_read (fd, &c, sizeof c) == SAFE_READ_ERROR
75      || lseek (fd, (off_t) 0, SEEK_SET) < 0
76      || full_write (fd, &c, sizeof c) != sizeof c
77      /* Maybe do this -- it's necessary on SunOS 4.1.3 with some combination
78	 of patches, but that system doesn't use this code: it has utimes.
79	 || fsync (fd) < 0
80      */
81      || (st.st_size == 0 && ftruncate (fd, st.st_size) < 0))
82    {
83      saved_errno = errno;
84      status = -1;
85    }
86
87  if (0 <= fd)
88    {
89      if (close (fd) < 0)
90	status = -1;
91
92      /* If there was a prior failure, use the saved errno value.
93	 But if the only failure was in the close, don't change errno.  */
94      if (saved_errno)
95	errno = saved_errno;
96    }
97
98  return status;
99#endif
100}
101
102int
103rpl_utime (const char *file, const struct utimbuf *times)
104{
105  if (times)
106    return utime (file, times);
107
108  return utime_null (file);
109}
110