include/linux/time.h

   1 #ifndef _LINUX_TIME_H
   2 #define _LINUX_TIME_H
   3
   4 #include <linux/types.h>
   5
   6 #define _DEFUN(a,b,c) a(c)
   7 #define _CONST const
   8 #define _AND ,
   9
  10 #define _REENT_ONLY
  11
  12 #define SECSPERMIN      60L
  13 #define MINSPERHOUR     60L
  14 #define HOURSPERDAY     24L
  15 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
  16 #define SECSPERDAY      (SECSPERHOUR * HOURSPERDAY)
  17 #define DAYSPERWEEK     7
  18 #define MONSPERYEAR     12
  19
  20 #define YEAR_BASE       1900
  21 #define EPOCH_YEAR      1970
  22 #define EPOCH_WDAY      4
  23
  24 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
  25
  26
  27 /* Used by other time functions.  */
  28 struct tm {
  29     int tm_sec;                   /* Seconds.     [0-60] (1 leap second) */
  30     int tm_min;                   /* Minutes.     [0-59] */
  31     int tm_hour;                  /* Hours.       [0-23] */
  32     int tm_mday;                  /* Day.         [1-31] */
  33     int tm_mon;                   /* Month.       [0-11] */
  34     int tm_year;                  /* Year - 1900.  */
  35     int tm_wday;                  /* Day of week. [0-6] */
  36     int tm_yday;                  /* Days in year.[0-365] */
  37     int tm_isdst;                 /* DST.         [-1/0/1]*/
  38
  39 # ifdef __USE_BSD
  40     long int tm_gmtoff;           /* Seconds east of UTC.  */
  41     __const char *tm_zone;        /* Timezone abbreviation.  */
  42 # else
  43     long int __tm_gmtoff;         /* Seconds east of UTC.  */
  44     __const char *__tm_zone;      /* Timezone abbreviation.  */
  45 # endif
  46 };
  47
  48 static inline char *
  49 _DEFUN (asctime_r, (tim_p, result),
  50         _CONST struct tm *tim_p _AND
  51         char *result)
  52 {
  53     static _CONST char day_name[7][3] = {
  54         "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
  55     };
  56     static _CONST char mon_name[12][3] = {
  57         "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  58         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
  59     };
  60
  61     sprintf (result, "%.3s %.3s %.2d %.2d:%.2d:%.2d %d\n",
  62             day_name[tim_p->tm_wday],
  63             mon_name[tim_p->tm_mon],
  64             tim_p->tm_mday, tim_p->tm_hour, tim_p->tm_min,
  65             tim_p->tm_sec, 1900 + tim_p->tm_year);
  66     return result;
  67 }
  68
  69 static inline struct tm *
  70 _DEFUN (localtime_r, (tim_p, res),
  71         _CONST time_t * tim_p _AND
  72         struct tm *res)
  73 {
  74     static _CONST int mon_lengths[2][MONSPERYEAR] = {
  75       {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
  76       {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
  77     } ;
  78
  79     static _CONST int year_lengths[2] = {
  80       365,
  81       366
  82     } ;
  83
  84     long days, rem;
  85     int y;
  86     int yleap;
  87     _CONST int *ip;
  88
  89     days = ((long) *tim_p) / SECSPERDAY;
  90     rem = ((long) *tim_p) % SECSPERDAY;
  91     while (rem < 0)
  92     {
  93         rem += SECSPERDAY;
  94         --days;
  95     }
  96     while (rem >= SECSPERDAY)
  97     {
  98         rem -= SECSPERDAY;
  99         ++days;
 100     }
 101
 102     /* compute hour, min, and sec */
 103     res->tm_hour = (int) (rem / SECSPERHOUR);
 104     rem %= SECSPERHOUR;
 105     res->tm_min = (int) (rem / SECSPERMIN);
 106     res->tm_sec = (int) (rem % SECSPERMIN);
 107
 108     /* compute day of week */
 109     if ((res->tm_wday = ((EPOCH_WDAY + days) % DAYSPERWEEK)) < 0)
 110         res->tm_wday += DAYSPERWEEK;
 111
 112     /* compute year & day of year */
 113     y = EPOCH_YEAR;
 114     if (days >= 0)
 115     {
 116         for (;;)
 117         {
 118             yleap = isleap(y);
 119             if (days < year_lengths[yleap])
 120                 break;
 121             y++;
 122             days -= year_lengths[yleap];
 123         }
 124     }
 125     else
 126     {
 127         do
 128         {
 129             --y;
 130             yleap = isleap(y);
 131             days += year_lengths[yleap];
 132         } while (days < 0);
 133     }
 134
 135     res->tm_year = y - YEAR_BASE;
 136     res->tm_yday = days;
 137     ip = mon_lengths[yleap];
 138     for (res->tm_mon = 0; days >= ip[res->tm_mon]; ++res->tm_mon)
 139         days -= ip[res->tm_mon];
 140     res->tm_mday = days + 1;
 141
 142     /* set daylight saving time flag */
 143     res->tm_isdst = -1;
 144
 145     return (res);
 146 }
 147
 148 static inline char *
 149 _DEFUN (ctime_r, (tim_p, result),
 150         _CONST time_t * tim_p _AND
 151         char * result)
 152
 153 {
 154     struct tm tm;
 155     return asctime_r (localtime_r (tim_p, &tm), result);
 156 }
 157
 158 #endif