time/time.h

   1 /* Copyright (C) 1991-1999, 2000 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 C99 Standard: 7.23 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
  40 /* This defines CLOCKS_PER_SEC, which is the number of processor clock
  41    ticks per second.  */
  42 # include <bits/time.h>
  43
  44 /* This is the obsolete POSIX.1-1988 name for the same constant.  */
  45 # ifdef __USE_POSIX
  46 #  ifndef CLK_TCK
  47 #   define CLK_TCK      CLOCKS_PER_SEC
  48 #  endif
  49 # endif
  50
  51 #endif /* <time.h> included.  */
  52
  53 #if !defined __clock_t_defined && (defined _TIME_H || defined __need_clock_t)
  54 # define __clock_t_defined      1
  55
  56 # include <bits/types.h>
  57
  58 /* Returned by `clock'.  */
  59 typedef __clock_t clock_t;
  60
  61 #endif /* clock_t not defined and <time.h> or need clock_t.  */
  62 #undef  __need_clock_t
  63
  64 #if !defined __time_t_defined && (defined _TIME_H || defined __need_time_t)
  65 # define __time_t_defined       1
  66
  67 # include <bits/types.h>
  68
  69 /* Returned by `time'.  */
  70 typedef __time_t time_t;
  71
  72 #endif /* time_t not defined and <time.h> or need time_t.  */
  73 #undef  __need_time_t
  74
  75 #if !defined __clockid_t_defined && \
  76    ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_clockid_t)
  77 # define __clockid_t_defined    1
  78
  79 # include <bits/types.h>
  80
  81 /* Clock ID used in clock and timer functions.  */
  82 typedef __clockid_t clockid_t;
  83
  84 #endif /* clockid_t not defined and <time.h> or need clockid_t.  */
  85 #undef  __clockid_time_t
  86
  87 #if !defined __timer_t_defined && \
  88     ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_timer_t)
  89 # define __timer_t_defined      1
  90
  91 # include <bits/types.h>
  92
  93 /* Timer ID returned by `timer_create'.  */
  94 typedef __timer_t timer_t;
  95
  96 #endif /* timer_t not defined and <time.h> or need timer_t.  */
  97 #undef  __need_timer_t
  98
  99
 100 #if !defined __timespec_defined && \
 101     ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_timespec)
 102 # define __timespec_defined     1
 103
 104 /* POSIX.1b structure for a time value.  This is like a `struct timeval' but
 105    has nanoseconds instead of microseconds.  */
 106 struct timespec
 107   {
 108     long int tv_sec;            /* Seconds.  */
 109     long int tv_nsec;           /* Nanoseconds.  */
 110   };
 111
 112 #endif /* timespec not defined and <time.h> or need timespec.  */
 113 #undef  __need_timespec
 114
 115
 116 #ifdef  _TIME_H
 117 /* Used by other time functions.  */
 118 struct tm
 119 {
 120   int tm_sec;                   /* Seconds.     [0-60] (1 leap second) */
 121   int tm_min;                   /* Minutes.     [0-59] */
 122   int tm_hour;                  /* Hours.       [0-23] */
 123   int tm_mday;                  /* Day.         [1-31] */
 124   int tm_mon;                   /* Month.       [0-11] */
 125   int tm_year;                  /* Year - 1900.  */
 126   int tm_wday;                  /* Day of week. [0-6] */
 127   int tm_yday;                  /* Days in year.[0-365] */
 128   int tm_isdst;                 /* DST.         [-1/0/1]*/
 129
 130 # ifdef __USE_BSD
 131   long int tm_gmtoff;           /* Seconds east of UTC.  */
 132   __const char *tm_zone;        /* Timezone abbreviation.  */
 133 # else
 134   long int __tm_gmtoff;         /* Seconds east of UTC.  */
 135   __const char *__tm_zone;      /* Timezone abbreviation.  */
 136 # endif
 137 };
 138
 139
 140 #ifdef __USE_POSIX199309
 141 /* POSIX.1b structure for timer start values and intervals.  */
 142 struct itimerspec
 143   {
 144     struct timespec it_interval;
 145     struct timespec it_value;
 146   };
 147
 148 /* We can use a simple forward declaration.  */
 149 struct sigevent;
 150
 151 #endif  /* POSIX.1b */
 152
 153 #ifdef __USE_XOPEN2K
 154 # ifndef __pid_t_defined
 155 typedef __pid_t pid_t;
 156 #  define __pid_t_defined
 157 # endif
 158 #endif
 159
 160
 161 /* Time used by the program so far (user time + system time).
 162    The result / CLOCKS_PER_SECOND is program time in seconds.  */
 163 extern clock_t clock (void) __THROW;
 164
 165 /* Return the current time and put it in *TIMER if TIMER is not NULL.  */
 166 extern time_t time (time_t *__timer) __THROW;
 167
 168 /* Return the difference between TIME1 and TIME0.  */
 169 extern double difftime (time_t __time1, time_t __time0)
 170      __THROW __attribute__ ((__const__));
 171
 172 /* Return the `time_t' representation of TP and normalize TP.  */
 173 extern time_t mktime (struct tm *__tp) __THROW;
 174
 175
 176 /* Format TP into S according to FORMAT.
 177    Write no more than MAXSIZE characters and return the number
 178    of characters written, or 0 if it would exceed MAXSIZE.  */
 179 extern size_t strftime (char *__restrict __s, size_t __maxsize,
 180                         __const char *__restrict __format,
 181                         __const struct tm *__restrict __tp) __THROW;
 182
 183 # ifdef __USE_XOPEN
 184 /* Parse S according to FORMAT and store binary time information in TP.
 185    The return value is a pointer to the first unparsed character in S.  */
 186 extern char *strptime (__const char *__restrict __s,
 187                        __const char *__restrict __fmt, struct tm *__tp)
 188      __THROW;
 189 # endif
 190
 191
 192 /* Return the `struct tm' representation of *TIMER
 193    in Universal Coordinated Time (aka Greenwich Mean Time).  */
 194 extern struct tm *gmtime (__const time_t *__timer) __THROW;
 195
 196 /* Return the `struct tm' representation
 197    of *TIMER in the local timezone.  */
 198 extern struct tm *localtime (__const time_t *__timer) __THROW;
 199
 200 # if defined __USE_POSIX || defined __USE_MISC
 201 /* Return the `struct tm' representation of *TIMER in UTC,
 202    using *TP to store the result.  */
 203 extern struct tm *gmtime_r (__const time_t *__restrict __timer,
 204                             struct tm *__restrict __tp) __THROW;
 205
 206 /* Return the `struct tm' representation of *TIMER in local time,
 207    using *TP to store the result.  */
 208 extern struct tm *localtime_r (__const time_t *__restrict __timer,
 209                                struct tm *__restrict __tp) __THROW;
 210 # endif /* POSIX or misc */
 211
 212 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 213    that is the representation of TP in this format.  */
 214 extern char *asctime (__const struct tm *__tp) __THROW;
 215
 216 /* Equivalent to `asctime (localtime (timer))'.  */
 217 extern char *ctime (__const time_t *__timer) __THROW;
 218
 219 # if defined __USE_POSIX || defined __USE_MISC
 220 /* Reentrant versions of the above functions.  */
 221
 222 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 223    that is the representation of TP in this format.  */
 224 extern char *asctime_r (__const struct tm *__restrict __tp,
 225                         char *__restrict __buf) __THROW;
 226
 227 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'.  */
 228 extern char *ctime_r (__const time_t *__restrict __timer,
 229                       char *__restrict __buf) __THROW;
 230 # endif /* POSIX or misc */
 231
 232
 233 /* Defined in localtime.c.  */
 234 extern char *__tzname[2];       /* Current timezone names.  */
 235 extern int __daylight;          /* If daylight-saving time is ever in use.  */
 236 extern long int __timezone;     /* Seconds west of UTC.  */
 237
 238
 239 # ifdef __USE_POSIX
 240 /* Same as above.  */
 241 extern char *tzname[2];
 242
 243 /* Set time conversion information from the TZ environment variable.
 244    If TZ is not defined, a locale-dependent default is used.  */
 245 extern void tzset (void) __THROW;
 246 # endif
 247
 248 # if defined __USE_SVID || defined __USE_XOPEN
 249 extern int daylight;
 250 extern long int timezone;
 251 # endif
 252
 253 # ifdef __USE_SVID
 254 /* Set the system time to *WHEN.
 255    This call is restricted to the superuser.  */
 256 extern int stime (__const time_t *__when) __THROW;
 257 # endif
 258
 259
 260 /* Nonzero if YEAR is a leap year (every 4 years,
 261    except every 100th isn't, and every 400th is).  */
 262 # define __isleap(year) \
 263   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 264
 265
 266 # ifdef __USE_MISC
 267 /* Miscellaneous functions many Unices inherited from the public domain
 268    localtime package.  These are included only for compatibility.  */
 269
 270 /* Like `mktime', but for TP represents Universal Time, not local time.  */
 271 extern time_t timegm (struct tm *__tp) __THROW;
 272
 273 /* Another name for `mktime'.  */
 274 extern time_t timelocal (struct tm *__tp) __THROW;
 275
 276 /* Return the number of days in YEAR.  */
 277 extern int dysize (int __year) __THROW  __attribute__ ((__const__));
 278 # endif
 279
 280
 281 # ifdef __USE_POSIX199309
 282 /* Pause execution for a number of nanoseconds.  */
 283 extern int nanosleep (__const struct timespec *__requested_time,
 284                       struct timespec *__remaining) __THROW;
 285
 286
 287 /* Get resolution of clock CLOCK_ID.  */
 288 extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
 289
 290 /* Get current value of clock CLOCK_ID and store it in TP.  */
 291 extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
 292
 293 /* Set clock CLOCK_ID to value TP.  */
 294 extern int clock_settime (clockid_t __clock_id, __const struct timespec *__tp)
 295      __THROW;
 296
 297 #  ifdef __USE_XOPEN2K
 298 /* High-resolution sleep with the specified clock.  */
 299 extern int clock_nanosleep (clockid_t __clock_id, int __flags,
 300                             __const struct timespec *__req,
 301                             struct timespec *__rem) __THROW;
 302
 303 /* Return clock ID for CPU-time clock.  */
 304 extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
 305 #  endif
 306
 307
 308 /* Create new per-process timer using CLOCK_ID.  */
 309 extern int timer_create (clockid_t __clock_id,
 310                          struct sigevent *__restrict __evp,
 311                          timer_t *__restrict __timerid) __THROW;
 312
 313 /* Delete timer TIMERID.  */
 314 extern int timer_delete (timer_t __timerid) __THROW;
 315
 316 /* Set timer TIMERID to VALUE, returning old value in OVLAUE.  */
 317 extern int timer_settime (timer_t __timerid, int __flags,
 318                           __const struct itimerspec *__restrict __value,
 319                           struct itimerspec *__restrict __ovalue) __THROW;
 320
 321 /* Get current value of timer TIMERID and store it in VLAUE.  */
 322 extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
 323      __THROW;
 324
 325 /* Get expiration overrun for timer TIMERID.  */
 326 extern int timer_getoverrun (timer_t __timerid) __THROW;
 327 # endif
 328
 329
 330 # ifdef __USE_XOPEN_EXTENDED
 331 /* Set to one of the following values to indicate an error.
 332      1  the DATEMSK environment variable is null or undefined,
 333      2  the template file cannot be opened for reading,
 334      3  failed to get file status information,
 335      4  the template file is not a regular file,
 336      5  an error is encountered while reading the template file,
 337      6  memory allication failed (not enough memory available),
 338      7  there is no line in the template that matches the input,
 339      8  invalid input specification Example: February 31 or a time is
 340         specified that can not be represented in a time_t (representing
 341         the time in seconds since 00:00:00 UTC, January 1, 1970) */
 342 extern int getdate_err;
 343
 344 /* Parse the given string as a date specification and return a value
 345    representing the value.  The templates from the file identified by
 346    the environment variable DATEMSK are used.  In case of an error
 347    `getdate_err' is set.  */
 348 extern struct tm *getdate (__const char *__string) __THROW;
 349 # endif
 350
 351 # ifdef __USE_GNU
 352 /* Since `getdate' is not reentrant because of the use of `getdate_err'
 353    and the static buffer to return the result in, we provide a thread-safe
 354    variant.  The functionality is the same.  The result is returned in
 355    the buffer pointed to by RESBUFP and in case of an error the return
 356    value is != 0 with the same values as given above for `getdate_err'.  */
 357 extern int getdate_r (__const char *__restrict __string,
 358                       struct tm *__restrict __resbufp) __THROW;
 359 # endif
 360
 361
 362 __END_DECLS
 363
 364 #endif /* <time.h> included.  */
 365
 366 #endif /* <time.h> not already included.  */