1/* stat-related time functions.
2
3   Copyright (C) 2005, 2007 Free Software Foundation, Inc.
4
5   This program is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 2, or (at your option)
8   any later version.
9
10   This program is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program; if not, write to the Free Software Foundation,
17   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
18
19/* Written by Paul Eggert.  */
20
21#ifndef STAT_TIME_H
22#define STAT_TIME_H 1
23
24#include <sys/stat.h>
25#include <time.h>
26
27/* STAT_TIMESPEC (ST, ST_XTIM) is the ST_XTIM member for *ST of type
28   struct timespec, if available.  If not, then STAT_TIMESPEC_NS (ST,
29   ST_XTIM) is the nanosecond component of the ST_XTIM member for *ST,
30   if available.  ST_XTIM can be st_atim, st_ctim, st_mtim, or st_birthtim
31   for access, status change, data modification, or birth (creation)
32   time respectively.
33
34   These macros are private to stat-time.h.  */
35#if defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC
36# ifdef TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC
37#  define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim)
38# else
39#  define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec)
40# endif
41#elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC
42# define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec)
43#elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC
44# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec)
45#elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC
46# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec)
47#endif
48
49/* Return the nanosecond component of *ST's access time.  */
50static inline long int
51get_stat_atime_ns (struct stat const *st)
52{
53# if defined STAT_TIMESPEC
54  return STAT_TIMESPEC (st, st_atim).tv_nsec;
55# elif defined STAT_TIMESPEC_NS
56  return STAT_TIMESPEC_NS (st, st_atim);
57# else
58  return 0;
59# endif
60}
61
62/* Return the nanosecond component of *ST's status change time.  */
63static inline long int
64get_stat_ctime_ns (struct stat const *st)
65{
66# if defined STAT_TIMESPEC
67  return STAT_TIMESPEC (st, st_ctim).tv_nsec;
68# elif defined STAT_TIMESPEC_NS
69  return STAT_TIMESPEC_NS (st, st_ctim);
70# else
71  return 0;
72# endif
73}
74
75/* Return the nanosecond component of *ST's data modification time.  */
76static inline long int
77get_stat_mtime_ns (struct stat const *st)
78{
79# if defined STAT_TIMESPEC
80  return STAT_TIMESPEC (st, st_mtim).tv_nsec;
81# elif defined STAT_TIMESPEC_NS
82  return STAT_TIMESPEC_NS (st, st_mtim);
83# else
84  return 0;
85# endif
86}
87
88/* Return the nanosecond component of *ST's birth time.  */
89static inline long int
90get_stat_birthtime_ns (struct stat const *st)
91{
92# if defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC
93  return STAT_TIMESPEC (st, st_birthtim).tv_nsec;
94# elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
95  return STAT_TIMESPEC_NS (st, st_birthtim);
96# else
97  return 0;
98# endif
99}
100
101/* Return *ST's access time.  */
102static inline struct timespec
103get_stat_atime (struct stat const *st)
104{
105#ifdef STAT_TIMESPEC
106  return STAT_TIMESPEC (st, st_atim);
107#else
108  struct timespec t;
109  t.tv_sec = st->st_atime;
110  t.tv_nsec = get_stat_atime_ns (st);
111  return t;
112#endif
113}
114
115/* Return *ST's status change time.  */
116static inline struct timespec
117get_stat_ctime (struct stat const *st)
118{
119#ifdef STAT_TIMESPEC
120  return STAT_TIMESPEC (st, st_ctim);
121#else
122  struct timespec t;
123  t.tv_sec = st->st_ctime;
124  t.tv_nsec = get_stat_ctime_ns (st);
125  return t;
126#endif
127}
128
129/* Return *ST's data modification time.  */
130static inline struct timespec
131get_stat_mtime (struct stat const *st)
132{
133#ifdef STAT_TIMESPEC
134  return STAT_TIMESPEC (st, st_mtim);
135#else
136  struct timespec t;
137  t.tv_sec = st->st_mtime;
138  t.tv_nsec = get_stat_mtime_ns (st);
139  return t;
140#endif
141}
142
143/* Return *ST's birth time, if available; otherwise return a value
144   with negative tv_nsec.  */
145static inline struct timespec
146get_stat_birthtime (struct stat const *st)
147{
148  struct timespec t;
149
150#if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
151     || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC)
152  t = STAT_TIMESPEC (st, st_birthtim);
153#elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
154  t.tv_sec = st->st_birthtime;
155  t.tv_nsec = st->st_birthtimensec;
156#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
157  /* Woe32 native platforms (but not Cygwin) put the "file creation
158     time" in st_ctime (!).  See
159     <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>.  */
160  t.tv_sec = st->st_ctime;
161  t.tv_nsec = 0;
162#else
163  /* Birth time is not supported.  Set tv_sec to avoid undefined behavior.  */
164  t.tv_sec = -1;
165  t.tv_nsec = -1;
166#endif
167
168#if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
169     || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \
170     || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
171  /* FreeBSD and NetBSD sometimes signal the absence of knowledge by
172     using zero.  Attempt to work around this problem.  Alas, this can
173     report failure even for valid time stamps.  Also, NetBSD
174     sometimes returns junk in the birth time fields; work around this
175     bug if it it is detected.  There's no need to detect negative
176     tv_nsec junk as negative tv_nsec already indicates an error.  */
177  if (t.tv_sec == 0 || 1000000000 <= t.tv_nsec)
178    t.tv_nsec = -1;
179#endif
180
181  return t;
182}
183
184#endif
185