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 #include <sys/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.  */
  50 static inline long int
  51 get_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.  */
  63 static inline long int
  64 get_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.  */
  76 static inline long int
  77 get_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.  */
  89 static inline long int
  90 get_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   /* Avoid a "parameter unused" warning.  */
  98   (void) st;
  99   return 0;
 100 # endif
 101 }
 102
 103 /* Return *ST's access time.  */
 104 static inline struct timespec
 105 get_stat_atime (struct stat const *st)
 106 {
 107 #ifdef STAT_TIMESPEC
 108   return STAT_TIMESPEC (st, st_atim);
 109 #else
 110   struct timespec t;
 111   t.tv_sec = st->st_atime;
 112   t.tv_nsec = get_stat_atime_ns (st);
 113   return t;
 114 #endif
 115 }
 116
 117 /* Return *ST's status change time.  */
 118 static inline struct timespec
 119 get_stat_ctime (struct stat const *st)
 120 {
 121 #ifdef STAT_TIMESPEC
 122   return STAT_TIMESPEC (st, st_ctim);
 123 #else
 124   struct timespec t;
 125   t.tv_sec = st->st_ctime;
 126   t.tv_nsec = get_stat_ctime_ns (st);
 127   return t;
 128 #endif
 129 }
 130
 131 /* Return *ST's data modification time.  */
 132 static inline struct timespec
 133 get_stat_mtime (struct stat const *st)
 134 {
 135 #ifdef STAT_TIMESPEC
 136   return STAT_TIMESPEC (st, st_mtim);
 137 #else
 138   struct timespec t;
 139   t.tv_sec = st->st_mtime;
 140   t.tv_nsec = get_stat_mtime_ns (st);
 141   return t;
 142 #endif
 143 }
 144
 145 /* Return *ST's birth time, if available; otherwise return a value
 146    with tv_sec and tv_nsec both equal to -1.  */
 147 static inline struct timespec
 148 get_stat_birthtime (struct stat const *st)
 149 {
 150   struct timespec t;
 151
 152 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
 153      || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC)
 154   t = STAT_TIMESPEC (st, st_birthtim);
 155 #elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
 156   t.tv_sec = st->st_birthtime;
 157   t.tv_nsec = st->st_birthtimensec;
 158 #elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 159   /* Native Windows platforms (but not Cygwin) put the "file creation
 160      time" in st_ctime (!).  See
 161      <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>.  */
 162   t.tv_sec = st->st_ctime;
 163   t.tv_nsec = 0;
 164 #else
 165   /* Birth time is not supported.  */
 166   t.tv_sec = -1;
 167   t.tv_nsec = -1;
 168   /* Avoid a "parameter unused" warning.  */
 169   (void) st;
 170 #endif
 171
 172 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
 173      || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \
 174      || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
 175   /* FreeBSD and NetBSD sometimes signal the absence of knowledge by
 176      using zero.  Attempt to work around this problem.  Alas, this can
 177      report failure even for valid time stamps.  Also, NetBSD
 178      sometimes returns junk in the birth time fields; work around this
 179      bug if it is detected.  */
 180   if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
 181     {
 182       t.tv_sec = -1;
 183       t.tv_nsec = -1;
 184     }
 185 #endif
 186
 187   return t;
 188 }
 189
 190 #endif