time/time.h

   1 /* Copyright (C) 1991,92,93,94,95,96,97,98,99 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  *      ISO C Standard: 4.12 DATE and TIME      <time.h>
  21  */
  22
  23 #ifndef _TIME_H
  24
  25 #if (! defined __need_time_t && !defined __need_clock_t && \
  26      ! defined __need_timespec)
  27 # define _TIME_H        1
  28 # include <features.h>
  29
  30 __BEGIN_DECLS
  31
  32 #endif
  33
  34 #ifdef  _TIME_H
  35 /* Get size_t and NULL from <stddef.h>.  */
  36 # define __need_size_t
  37 # define __need_NULL
  38 # include <stddef.h>
  39 #endif /* <time.h> included.  */
  40
  41
  42
  43 #ifdef  _TIME_H
  44
  45 /* This defines CLOCKS_PER_SEC, which is the number of processor clock
  46    ticks per second.  */
  47 # include <bits/time.h>
  48
  49 /* This is the obsolete POSIX.1-1988 name for the same constant.  */
  50 # ifdef __USE_POSIX
  51 #  ifndef CLK_TCK
  52 #   define CLK_TCK      CLOCKS_PER_SEC
  53 #  endif
  54 # endif
  55
  56 #endif /* <time.h> included.  */
  57
  58
  59 #if !defined __clock_t_defined && (defined _TIME_H || defined __need_clock_t)
  60 # define __clock_t_defined      1
  61
  62 # include <bits/types.h>
  63
  64 /* Returned by `clock'.  */
  65 typedef __clock_t clock_t;
  66
  67 #endif /* clock_t not defined and <time.h> or need clock_t.  */
  68 #undef  __need_clock_t
  69
  70 #if !defined __time_t_defined && (defined _TIME_H || defined __need_time_t)
  71 # define __time_t_defined       1
  72
  73 # include <bits/types.h>
  74
  75 /* Returned by `time'.  */
  76 typedef __time_t time_t;
  77
  78 #endif /* time_t not defined and <time.h> or need time_t.  */
  79 #undef  __need_time_t
  80
  81
  82 #if !defined __timespec_defined && \
  83     ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_timespec)
  84 # define __timespec_defined     1
  85
  86 /* POSIX.4 structure for a time value.  This is like a `struct timeval' but
  87    has nanoseconds instead of microseconds.  */
  88 struct timespec
  89   {
  90     long int tv_sec;            /* Seconds.  */
  91     long int tv_nsec;           /* Nanoseconds.  */
  92   };
  93
  94 #endif /* timespec not defined and <time.h> or need timespec.  */
  95 #undef  __need_timespec
  96
  97
  98 #ifdef  _TIME_H
  99 /* Used by other time functions.  */
 100 struct tm
 101 {
 102   int tm_sec;                   /* Seconds.     [0-60] (1 leap second) */
 103   int tm_min;                   /* Minutes.     [0-59] */
 104   int tm_hour;                  /* Hours.       [0-23] */
 105   int tm_mday;                  /* Day.         [1-31] */
 106   int tm_mon;                   /* Month.       [0-11] */
 107   int tm_year;                  /* Year - 1900.  */
 108   int tm_wday;                  /* Day of week. [0-6] */
 109   int tm_yday;                  /* Days in year.[0-365] */
 110   int tm_isdst;                 /* DST.         [-1/0/1]*/
 111
 112 # ifdef __USE_BSD
 113   long int tm_gmtoff;           /* Seconds east of UTC.  */
 114   __const char *tm_zone;        /* Timezone abbreviation.  */
 115 # else
 116   long int __tm_gmtoff;         /* Seconds east of UTC.  */
 117   __const char *__tm_zone;      /* Timezone abbreviation.  */
 118 # endif
 119 };
 120
 121
 122 /* Time used by the program so far (user time + system time).
 123    The result / CLOCKS_PER_SECOND is program time in seconds.  */
 124 extern clock_t clock __P ((void));
 125
 126 /* Return the current time and put it in *TIMER if TIMER is not NULL.  */
 127 extern time_t time __P ((time_t *__timer));
 128
 129 /* Return the difference between TIME1 and TIME0.  */
 130 extern double difftime __P ((time_t __time1, time_t __time0))
 131      __attribute__ ((__const__));
 132
 133 /* Return the `time_t' representation of TP and normalize TP.  */
 134 extern time_t mktime __P ((struct tm *__tp));
 135
 136
 137 /* Format TP into S according to FORMAT.
 138    Write no more than MAXSIZE characters and return the number
 139    of characters written, or 0 if it would exceed MAXSIZE.  */
 140 extern size_t strftime __P ((char *__restrict __s, size_t __maxsize,
 141                              __const char *__restrict __format,
 142                              __const struct tm *__restrict __tp));
 143
 144 # ifdef __USE_XOPEN
 145 /* Parse S according to FORMAT and store binary time information in TP.
 146    The return value is a pointer to the first unparsed character in S.  */
 147 extern char *strptime __P ((__const char *__s, __const char *__fmt,
 148                             struct tm *__tp));
 149 # endif
 150
 151
 152 /* Return the `struct tm' representation of *TIMER
 153    in Universal Coordinated Time (aka Greenwich Mean Time).  */
 154 extern struct tm *gmtime __P ((__const time_t *__timer));
 155
 156 /* Return the `struct tm' representation
 157    of *TIMER in the local timezone.  */
 158 extern struct tm *localtime __P ((__const time_t *__timer));
 159
 160 # if defined __USE_POSIX || defined __USE_MISC
 161 /* Return the `struct tm' representation of *TIMER in UTC,
 162    using *TP to store the result.  */
 163 extern struct tm *__gmtime_r __P ((__const time_t *__restrict __timer,
 164                                    struct tm *__restrict __tp));
 165 extern struct tm *gmtime_r __P ((__const time_t *__restrict __timer,
 166                                  struct tm *__restrict __tp));
 167
 168 /* Return the `struct tm' representation of *TIMER in local time,
 169    using *TP to store the result.  */
 170 extern struct tm *localtime_r __P ((__const time_t *__restrict __timer,
 171                                     struct tm *__restrict __tp));
 172 # endif /* POSIX or misc */
 173
 174 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 175    that is the representation of TP in this format.  */
 176 extern char *asctime __P ((__const struct tm *__tp));
 177
 178 /* Equivalent to `asctime (localtime (timer))'.  */
 179 extern char *ctime __P ((__const time_t *__timer));
 180
 181 # if defined __USE_POSIX || defined __USE_MISC
 182 /* Reentrant versions of the above functions.  */
 183
 184 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 185    that is the representation of TP in this format.  */
 186 extern char *asctime_r __P ((__const struct tm *__restrict __tp,
 187                              char *__restrict __buf));
 188
 189 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'.  */
 190 extern char *ctime_r __P ((__const time_t *__restrict __timer,
 191                            char *__restrict __buf));
 192 # endif /* POSIX or misc */
 193
 194
 195 /* Defined in localtime.c.  */
 196 extern char *__tzname[2];       /* Current timezone names.  */
 197 extern int __daylight;          /* If daylight-saving time is ever in use.  */
 198 extern long int __timezone;     /* Seconds west of UTC.  */
 199
 200
 201 # ifdef __USE_POSIX
 202 /* Same as above.  */
 203 extern char *tzname[2];
 204
 205 /* Set time conversion information from the TZ environment variable.
 206    If TZ is not defined, a locale-dependent default is used.  */
 207 extern void tzset __P ((void));
 208 # endif
 209
 210 # if defined __USE_SVID || defined __USE_XOPEN
 211 extern int daylight;
 212 extern long int timezone;
 213 # endif
 214
 215 # ifdef __USE_SVID
 216 /* Set the system time to *WHEN.
 217    This call is restricted to the superuser.  */
 218 extern int stime __P ((__const time_t *__when));
 219 # endif
 220
 221
 222 /* Nonzero if YEAR is a leap year (every 4 years,
 223    except every 100th isn't, and every 400th is).  */
 224 # define __isleap(year) \
 225   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 226
 227
 228 # ifdef __USE_MISC
 229 /* Miscellaneous functions many Unices inherited from the public domain
 230    localtime package.  These are included only for compatibility.  */
 231
 232 /* Like `mktime', but for TP represents Universal Time, not local time.  */
 233 extern time_t timegm __P ((struct tm *__tp));
 234
 235 /* Another name for `mktime'.  */
 236 extern time_t timelocal __P ((struct tm *__tp));
 237
 238 /* Return the number of days in YEAR.  */
 239 extern int dysize __P ((int __year));
 240 # endif
 241
 242
 243 # ifdef __USE_POSIX199309
 244 /* Pause execution for a number of nanoseconds.  */
 245 extern int nanosleep __P ((__const struct timespec *__requested_time,
 246                            struct timespec *__remaining));
 247 # endif
 248
 249
 250 # ifdef __USE_XOPEN_EXTENDED
 251 /* Set to one of the following values to indicate an error.
 252      1  the DATEMSK environment variable is null or undefined,
 253      2  the template file cannot be opened for reading,
 254      3  failed to get file status information,
 255      4  the template file is not a regular file,
 256      5  an error is encountered while reading the template file,
 257      6  memory allication failed (not enough memory available),
 258      7  there is no line in the template that matches the input,
 259      8  invalid input specification Example: February 31 or a time is
 260         specified that can not be represented in a time_t (representing
 261         the time in seconds since 00:00:00 UTC, January 1, 1970) */
 262 extern int getdate_err;
 263
 264 /* Parse the given string as a date specification and return a value
 265    representing the value.  The templates from the file identified by
 266    the environment variable DATEMSK are used.  In case of an error
 267    `getdate_err' is set.  */
 268 extern struct tm *getdate __P ((__const char *__string));
 269 # endif
 270
 271 # ifdef __USE_GNU
 272 /* Since `getdate' is not reentrant because of the use of `getdate_err'
 273    and the static buffer to return the result in, we provide a thread-safe
 274    variant.  The functionality is the same.  The result is returned in
 275    the buffer pointed to by RESBUFP and in case of an error the return
 276    value is != 0 with the same values as given above for `getdate_err'.  */
 277 extern int getdate_r __P ((__const char *__restrict __string,
 278                            struct tm *__restrict __resbufp));
 279 # endif
 280
 281
 282 __END_DECLS
 283
 284 #endif /* <time.h> included.  */
 285
 286 #endif /* <time.h> not already included.  */