Tramp: Support unsetting HISTFILE.
[emacs.git] / lib / stat-time.h
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1 /* stat-related time functions.
3 Copyright (C) 2005, 2007, 2009-2015 Free Software Foundation, Inc.
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 3 of the License, or
8 (at your option) any later version.
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.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* Written by Paul Eggert. */
20 #ifndef STAT_TIME_H
21 #define STAT_TIME_H 1
23 #include <sys/stat.h>
24 #include <time.h>
26 #ifndef _GL_INLINE_HEADER_BEGIN
27 #error "Please include config.h first."
28 #endif
29 _GL_INLINE_HEADER_BEGIN
30 #ifndef _GL_STAT_TIME_INLINE
31 # define _GL_STAT_TIME_INLINE _GL_INLINE
32 #endif
34 /* STAT_TIMESPEC (ST, ST_XTIM) is the ST_XTIM member for *ST of type
35 struct timespec, if available. If not, then STAT_TIMESPEC_NS (ST,
36 ST_XTIM) is the nanosecond component of the ST_XTIM member for *ST,
37 if available. ST_XTIM can be st_atim, st_ctim, st_mtim, or st_birthtim
38 for access, status change, data modification, or birth (creation)
39 time respectively.
41 These macros are private to stat-time.h. */
42 #if defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC
43 # ifdef TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC
44 # define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim)
45 # else
46 # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec)
47 # endif
48 #elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC
49 # define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec)
50 #elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC
51 # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec)
52 #elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC
53 # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec)
54 #endif
56 /* Return the nanosecond component of *ST's access time. */
57 _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE
58 get_stat_atime_ns (struct stat const *st)
60 # if defined STAT_TIMESPEC
61 return STAT_TIMESPEC (st, st_atim).tv_nsec;
62 # elif defined STAT_TIMESPEC_NS
63 return STAT_TIMESPEC_NS (st, st_atim);
64 # else
65 return 0;
66 # endif
69 /* Return the nanosecond component of *ST's status change time. */
70 _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE
71 get_stat_ctime_ns (struct stat const *st)
73 # if defined STAT_TIMESPEC
74 return STAT_TIMESPEC (st, st_ctim).tv_nsec;
75 # elif defined STAT_TIMESPEC_NS
76 return STAT_TIMESPEC_NS (st, st_ctim);
77 # else
78 return 0;
79 # endif
82 /* Return the nanosecond component of *ST's data modification time. */
83 _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE
84 get_stat_mtime_ns (struct stat const *st)
86 # if defined STAT_TIMESPEC
87 return STAT_TIMESPEC (st, st_mtim).tv_nsec;
88 # elif defined STAT_TIMESPEC_NS
89 return STAT_TIMESPEC_NS (st, st_mtim);
90 # else
91 return 0;
92 # endif
95 /* Return the nanosecond component of *ST's birth time. */
96 _GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE
97 get_stat_birthtime_ns (struct stat const *st)
99 # if defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC
100 return STAT_TIMESPEC (st, st_birthtim).tv_nsec;
101 # elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
102 return STAT_TIMESPEC_NS (st, st_birthtim);
103 # else
104 /* Avoid a "parameter unused" warning. */
105 (void) st;
106 return 0;
107 # endif
110 /* Return *ST's access time. */
111 _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE
112 get_stat_atime (struct stat const *st)
114 #ifdef STAT_TIMESPEC
115 return STAT_TIMESPEC (st, st_atim);
116 #else
117 struct timespec t;
118 t.tv_sec = st->st_atime;
119 t.tv_nsec = get_stat_atime_ns (st);
120 return t;
121 #endif
124 /* Return *ST's status change time. */
125 _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE
126 get_stat_ctime (struct stat const *st)
128 #ifdef STAT_TIMESPEC
129 return STAT_TIMESPEC (st, st_ctim);
130 #else
131 struct timespec t;
132 t.tv_sec = st->st_ctime;
133 t.tv_nsec = get_stat_ctime_ns (st);
134 return t;
135 #endif
138 /* Return *ST's data modification time. */
139 _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE
140 get_stat_mtime (struct stat const *st)
142 #ifdef STAT_TIMESPEC
143 return STAT_TIMESPEC (st, st_mtim);
144 #else
145 struct timespec t;
146 t.tv_sec = st->st_mtime;
147 t.tv_nsec = get_stat_mtime_ns (st);
148 return t;
149 #endif
152 /* Return *ST's birth time, if available; otherwise return a value
153 with tv_sec and tv_nsec both equal to -1. */
154 _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE
155 get_stat_birthtime (struct stat const *st)
157 struct timespec t;
159 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
160 || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC)
161 t = STAT_TIMESPEC (st, st_birthtim);
162 #elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
163 t.tv_sec = st->st_birthtime;
164 t.tv_nsec = st->st_birthtimensec;
165 #elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
166 /* Native Windows platforms (but not Cygwin) put the "file creation
167 time" in st_ctime (!). See
168 <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>. */
169 t.tv_sec = st->st_ctime;
170 t.tv_nsec = 0;
171 #else
172 /* Birth time is not supported. */
173 t.tv_sec = -1;
174 t.tv_nsec = -1;
175 /* Avoid a "parameter unused" warning. */
176 (void) st;
177 #endif
179 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
180 || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \
181 || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
182 /* FreeBSD and NetBSD sometimes signal the absence of knowledge by
183 using zero. Attempt to work around this problem. Alas, this can
184 report failure even for valid time stamps. Also, NetBSD
185 sometimes returns junk in the birth time fields; work around this
186 bug if it is detected. */
187 if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
189 t.tv_sec = -1;
190 t.tv_nsec = -1;
192 #endif
194 return t;
197 _GL_INLINE_HEADER_END
199 #endif