lib/stat-time.h

   1 /* stat-related time functions.
   2
   3    Copyright (C) 2005, 2007, 2009-2012 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 3 of the License, or
   8    (at your option) 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, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 #ifndef STAT_TIME_H
  21 #define STAT_TIME_H 1
  22
  23 #include <sys/stat.h>
  24 #include <time.h>
  25
  26 /* STAT_TIMESPEC (ST, ST_XTIM) is the ST_XTIM member for *ST of type
  27    struct timespec, if available.  If not, then STAT_TIMESPEC_NS (ST,
  28    ST_XTIM) is the nanosecond component of the ST_XTIM member for *ST,
  29    if available.  ST_XTIM can be st_atim, st_ctim, st_mtim, or st_birthtim
  30    for access, status change, data modification, or birth (creation)
  31    time respectively.
  32
  33    These macros are private to stat-time.h.  */
  34 #if defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC
  35 # ifdef TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC
  36 #  define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim)
  37 # else
  38 #  define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec)
  39 # endif
  40 #elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC
  41 # define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec)
  42 #elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC
  43 # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec)
  44 #elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC
  45 # define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec)
  46 #endif
  47
  48 /* Return the nanosecond component of *ST's access time.  */
  49 static inline long int
  50 get_stat_atime_ns (struct stat const *st)
  51 {
  52 # if defined STAT_TIMESPEC
  53   return STAT_TIMESPEC (st, st_atim).tv_nsec;
  54 # elif defined STAT_TIMESPEC_NS
  55   return STAT_TIMESPEC_NS (st, st_atim);
  56 # else
  57   return 0;
  58 # endif
  59 }
  60
  61 /* Return the nanosecond component of *ST's status change time.  */
  62 static inline long int
  63 get_stat_ctime_ns (struct stat const *st)
  64 {
  65 # if defined STAT_TIMESPEC
  66   return STAT_TIMESPEC (st, st_ctim).tv_nsec;
  67 # elif defined STAT_TIMESPEC_NS
  68   return STAT_TIMESPEC_NS (st, st_ctim);
  69 # else
  70   return 0;
  71 # endif
  72 }
  73
  74 /* Return the nanosecond component of *ST's data modification time.  */
  75 static inline long int
  76 get_stat_mtime_ns (struct stat const *st)
  77 {
  78 # if defined STAT_TIMESPEC
  79   return STAT_TIMESPEC (st, st_mtim).tv_nsec;
  80 # elif defined STAT_TIMESPEC_NS
  81   return STAT_TIMESPEC_NS (st, st_mtim);
  82 # else
  83   return 0;
  84 # endif
  85 }
  86
  87 /* Return the nanosecond component of *ST's birth time.  */
  88 static inline long int
  89 get_stat_birthtime_ns (struct stat const *st)
  90 {
  91 # if defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC
  92   return STAT_TIMESPEC (st, st_birthtim).tv_nsec;
  93 # elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
  94   return STAT_TIMESPEC_NS (st, st_birthtim);
  95 # else
  96   /* Avoid a "parameter unused" warning.  */
  97   (void) st;
  98   return 0;
  99 # endif
 100 }
 101
 102 /* Return *ST's access time.  */
 103 static inline struct timespec
 104 get_stat_atime (struct stat const *st)
 105 {
 106 #ifdef STAT_TIMESPEC
 107   return STAT_TIMESPEC (st, st_atim);
 108 #else
 109   struct timespec t;
 110   t.tv_sec = st->st_atime;
 111   t.tv_nsec = get_stat_atime_ns (st);
 112   return t;
 113 #endif
 114 }
 115
 116 /* Return *ST's status change time.  */
 117 static inline struct timespec
 118 get_stat_ctime (struct stat const *st)
 119 {
 120 #ifdef STAT_TIMESPEC
 121   return STAT_TIMESPEC (st, st_ctim);
 122 #else
 123   struct timespec t;
 124   t.tv_sec = st->st_ctime;
 125   t.tv_nsec = get_stat_ctime_ns (st);
 126   return t;
 127 #endif
 128 }
 129
 130 /* Return *ST's data modification time.  */
 131 static inline struct timespec
 132 get_stat_mtime (struct stat const *st)
 133 {
 134 #ifdef STAT_TIMESPEC
 135   return STAT_TIMESPEC (st, st_mtim);
 136 #else
 137   struct timespec t;
 138   t.tv_sec = st->st_mtime;
 139   t.tv_nsec = get_stat_mtime_ns (st);
 140   return t;
 141 #endif
 142 }
 143
 144 /* Return *ST's birth time, if available; otherwise return a value
 145    with tv_sec and tv_nsec both equal to -1.  */
 146 static inline struct timespec
 147 get_stat_birthtime (struct stat const *st)
 148 {
 149   struct timespec t;
 150
 151 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
 152      || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC)
 153   t = STAT_TIMESPEC (st, st_birthtim);
 154 #elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
 155   t.tv_sec = st->st_birthtime;
 156   t.tv_nsec = st->st_birthtimensec;
 157 #elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 158   /* Native Windows platforms (but not Cygwin) put the "file creation
 159      time" in st_ctime (!).  See
 160      <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>.  */
 161   t.tv_sec = st->st_ctime;
 162   t.tv_nsec = 0;
 163 #else
 164   /* Birth time is not supported.  */
 165   t.tv_sec = -1;
 166   t.tv_nsec = -1;
 167   /* Avoid a "parameter unused" warning.  */
 168   (void) st;
 169 #endif
 170
 171 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
 172      || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \
 173      || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
 174   /* FreeBSD and NetBSD sometimes signal the absence of knowledge by
 175      using zero.  Attempt to work around this problem.  Alas, this can
 176      report failure even for valid time stamps.  Also, NetBSD
 177      sometimes returns junk in the birth time fields; work around this
 178      bug if it is detected.  */
 179   if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
 180     {
 181       t.tv_sec = -1;
 182       t.tv_nsec = -1;
 183     }
 184 #endif
 185
 186   return t;
 187 }
 188
 189 #endif