time/time.h

   1 /* Copyright (C) 1991-1999,2000,2001,2002,2003 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    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 # if !defined __STRICT_ANSI__ && !defined __USE_XOPEN2K
  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 __BEGIN_NAMESPACE_STD
  59 /* Returned by `clock'.  */
  60 typedef __clock_t clock_t;
  61 __END_NAMESPACE_STD
  62 #if defined __USE_XOPEN || defined __USE_POSIX || defined __USE_MISC
  63 __USING_NAMESPACE_STD(clock_t)
  64 #endif
  65
  66 #endif /* clock_t not defined and <time.h> or need clock_t.  */
  67 #undef  __need_clock_t
  68
  69 #if !defined __time_t_defined && (defined _TIME_H || defined __need_time_t)
  70 # define __time_t_defined       1
  71
  72 # include <bits/types.h>
  73
  74 __BEGIN_NAMESPACE_STD
  75 /* Returned by `time'.  */
  76 typedef __time_t time_t;
  77 __END_NAMESPACE_STD
  78 #if defined __USE_POSIX || defined __USE_MISC || defined __USE_SVID
  79 __USING_NAMESPACE_STD(time_t)
  80 #endif
  81
  82 #endif /* time_t not defined and <time.h> or need time_t.  */
  83 #undef  __need_time_t
  84
  85 #if !defined __clockid_t_defined && \
  86    ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_clockid_t)
  87 # define __clockid_t_defined    1
  88
  89 # include <bits/types.h>
  90
  91 /* Clock ID used in clock and timer functions.  */
  92 typedef __clockid_t clockid_t;
  93
  94 #endif /* clockid_t not defined and <time.h> or need clockid_t.  */
  95 #undef  __clockid_time_t
  96
  97 #if !defined __timer_t_defined && \
  98     ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_timer_t)
  99 # define __timer_t_defined      1
 100
 101 # include <bits/types.h>
 102
 103 /* Timer ID returned by `timer_create'.  */
 104 typedef __timer_t timer_t;
 105
 106 #endif /* timer_t not defined and <time.h> or need timer_t.  */
 107 #undef  __need_timer_t
 108
 109
 110 #if !defined __timespec_defined &&                              \
 111     ((defined _TIME_H &&                                        \
 112       (defined __USE_POSIX199309 || defined __USE_MISC)) ||     \
 113       defined __need_timespec)
 114 # define __timespec_defined     1
 115
 116 /* POSIX.1b structure for a time value.  This is like a `struct timeval' but
 117    has nanoseconds instead of microseconds.  */
 118 struct timespec
 119   {
 120     __time_t tv_sec;            /* Seconds.  */
 121     long int tv_nsec;           /* Nanoseconds.  */
 122   };
 123
 124 #endif /* timespec not defined and <time.h> or need timespec.  */
 125 #undef  __need_timespec
 126
 127
 128 #ifdef  _TIME_H
 129 __BEGIN_NAMESPACE_STD
 130 /* Used by other time functions.  */
 131 struct tm
 132 {
 133   int tm_sec;                   /* Seconds.     [0-60] (1 leap second) */
 134   int tm_min;                   /* Minutes.     [0-59] */
 135   int tm_hour;                  /* Hours.       [0-23] */
 136   int tm_mday;                  /* Day.         [1-31] */
 137   int tm_mon;                   /* Month.       [0-11] */
 138   int tm_year;                  /* Year - 1900.  */
 139   int tm_wday;                  /* Day of week. [0-6] */
 140   int tm_yday;                  /* Days in year.[0-365] */
 141   int tm_isdst;                 /* DST.         [-1/0/1]*/
 142
 143 #ifdef  __USE_BSD
 144   long int tm_gmtoff;           /* Seconds east of UTC.  */
 145   __const char *tm_zone;        /* Timezone abbreviation.  */
 146 #else
 147   long int __tm_gmtoff;         /* Seconds east of UTC.  */
 148   __const char *__tm_zone;      /* Timezone abbreviation.  */
 149 #endif
 150 };
 151 __END_NAMESPACE_STD
 152 #if defined __USE_XOPEN || defined __USE_POSIX || defined __USE_MISC
 153 __USING_NAMESPACE_STD(tm)
 154 #endif
 155
 156
 157 #ifdef __USE_POSIX199309
 158 /* POSIX.1b structure for timer start values and intervals.  */
 159 struct itimerspec
 160   {
 161     struct timespec it_interval;
 162     struct timespec it_value;
 163   };
 164
 165 /* We can use a simple forward declaration.  */
 166 struct sigevent;
 167
 168 #endif  /* POSIX.1b */
 169
 170 #ifdef __USE_XOPEN2K
 171 # ifndef __pid_t_defined
 172 typedef __pid_t pid_t;
 173 #  define __pid_t_defined
 174 # endif
 175 #endif
 176
 177
 178 __BEGIN_NAMESPACE_STD
 179 /* Time used by the program so far (user time + system time).
 180    The result / CLOCKS_PER_SECOND is program time in seconds.  */
 181 extern clock_t clock (void) __THROW;
 182
 183 /* Return the current time and put it in *TIMER if TIMER is not NULL.  */
 184 extern time_t time (time_t *__timer) __THROW;
 185
 186 /* Return the difference between TIME1 and TIME0.  */
 187 extern double difftime (time_t __time1, time_t __time0)
 188      __THROW __attribute__ ((__const__));
 189
 190 /* Return the `time_t' representation of TP and normalize TP.  */
 191 extern time_t mktime (struct tm *__tp) __THROW;
 192
 193
 194 /* Format TP into S according to FORMAT.
 195    Write no more than MAXSIZE characters and return the number
 196    of characters written, or 0 if it would exceed MAXSIZE.  */
 197 extern size_t strftime (char *__restrict __s, size_t __maxsize,
 198                         __const char *__restrict __format,
 199                         __const struct tm *__restrict __tp) __THROW;
 200 __END_NAMESPACE_STD
 201
 202 # ifdef __USE_XOPEN
 203 /* Parse S according to FORMAT and store binary time information in TP.
 204    The return value is a pointer to the first unparsed character in S.  */
 205 extern char *strptime (__const char *__restrict __s,
 206                        __const char *__restrict __fmt, struct tm *__tp)
 207      __THROW;
 208 # endif
 209
 210 # ifdef __USE_GNU
 211 /* Similar to the two functions above but take the information from
 212    the provided locale and not the global locale.  */
 213 # include <xlocale.h>
 214
 215 extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
 216                           __const char *__restrict __format,
 217                           __const struct tm *__restrict __tp,
 218                           __locale_t __loc) __THROW;
 219
 220 extern char *strptime_l (__const char *__restrict __s,
 221                          __const char *__restrict __fmt, struct tm *__tp,
 222                          __locale_t __loc) __THROW;
 223 # endif
 224
 225
 226 __BEGIN_NAMESPACE_STD
 227 /* Return the `struct tm' representation of *TIMER
 228    in Universal Coordinated Time (aka Greenwich Mean Time).  */
 229 extern struct tm *gmtime (__const time_t *__timer) __THROW;
 230
 231 /* Return the `struct tm' representation
 232    of *TIMER in the local timezone.  */
 233 extern struct tm *localtime (__const time_t *__timer) __THROW;
 234 __END_NAMESPACE_STD
 235
 236 # if defined __USE_POSIX || defined __USE_MISC
 237 /* Return the `struct tm' representation of *TIMER in UTC,
 238    using *TP to store the result.  */
 239 extern struct tm *gmtime_r (__const time_t *__restrict __timer,
 240                             struct tm *__restrict __tp) __THROW;
 241
 242 /* Return the `struct tm' representation of *TIMER in local time,
 243    using *TP to store the result.  */
 244 extern struct tm *localtime_r (__const time_t *__restrict __timer,
 245                                struct tm *__restrict __tp) __THROW;
 246 # endif /* POSIX or misc */
 247
 248 __BEGIN_NAMESPACE_STD
 249 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 250    that is the representation of TP in this format.  */
 251 extern char *asctime (__const struct tm *__tp) __THROW;
 252
 253 /* Equivalent to `asctime (localtime (timer))'.  */
 254 extern char *ctime (__const time_t *__timer) __THROW;
 255 __END_NAMESPACE_STD
 256
 257 # if defined __USE_POSIX || defined __USE_MISC
 258 /* Reentrant versions of the above functions.  */
 259
 260 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 261    that is the representation of TP in this format.  */
 262 extern char *asctime_r (__const struct tm *__restrict __tp,
 263                         char *__restrict __buf) __THROW;
 264
 265 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'.  */
 266 extern char *ctime_r (__const time_t *__restrict __timer,
 267                       char *__restrict __buf) __THROW;
 268 # endif /* POSIX or misc */
 269
 270
 271 /* Defined in localtime.c.  */
 272 extern char *__tzname[2];       /* Current timezone names.  */
 273 extern int __daylight;          /* If daylight-saving time is ever in use.  */
 274 extern long int __timezone;     /* Seconds west of UTC.  */
 275
 276
 277 # ifdef __USE_POSIX
 278 /* Same as above.  */
 279 extern char *tzname[2];
 280
 281 /* Set time conversion information from the TZ environment variable.
 282    If TZ is not defined, a locale-dependent default is used.  */
 283 extern void tzset (void) __THROW;
 284 # endif
 285
 286 # if defined __USE_SVID || defined __USE_XOPEN
 287 extern int daylight;
 288 extern long int timezone;
 289 # endif
 290
 291 # ifdef __USE_SVID
 292 /* Set the system time to *WHEN.
 293    This call is restricted to the superuser.  */
 294 extern int stime (__const time_t *__when) __THROW;
 295 # endif
 296
 297
 298 /* Nonzero if YEAR is a leap year (every 4 years,
 299    except every 100th isn't, and every 400th is).  */
 300 # define __isleap(year) \
 301   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 302
 303
 304 # ifdef __USE_MISC
 305 /* Miscellaneous functions many Unices inherited from the public domain
 306    localtime package.  These are included only for compatibility.  */
 307
 308 /* Like `mktime', but for TP represents Universal Time, not local time.  */
 309 extern time_t timegm (struct tm *__tp) __THROW;
 310
 311 /* Another name for `mktime'.  */
 312 extern time_t timelocal (struct tm *__tp) __THROW;
 313
 314 /* Return the number of days in YEAR.  */
 315 extern int dysize (int __year) __THROW  __attribute__ ((__const__));
 316 # endif
 317
 318
 319 # ifdef __USE_POSIX199309
 320 /* Pause execution for a number of nanoseconds.
 321
 322    This function is a cancellation point and therefore not marked with
 323    __THROW.  */
 324 extern int nanosleep (__const struct timespec *__requested_time,
 325                       struct timespec *__remaining);
 326
 327
 328 /* Get resolution of clock CLOCK_ID.  */
 329 extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
 330
 331 /* Get current value of clock CLOCK_ID and store it in TP.  */
 332 extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
 333
 334 /* Set clock CLOCK_ID to value TP.  */
 335 extern int clock_settime (clockid_t __clock_id, __const struct timespec *__tp)
 336      __THROW;
 337
 338 #  ifdef __USE_XOPEN2K
 339 /* High-resolution sleep with the specified clock.
 340
 341    This function is a cancellation point and therefore not marked with
 342    __THROW.  */
 343 extern int clock_nanosleep (clockid_t __clock_id, int __flags,
 344                             __const struct timespec *__req,
 345                             struct timespec *__rem);
 346
 347 /* Return clock ID for CPU-time clock.  */
 348 extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
 349 #  endif
 350
 351
 352 /* Create new per-process timer using CLOCK_ID.  */
 353 extern int timer_create (clockid_t __clock_id,
 354                          struct sigevent *__restrict __evp,
 355                          timer_t *__restrict __timerid) __THROW;
 356
 357 /* Delete timer TIMERID.  */
 358 extern int timer_delete (timer_t __timerid) __THROW;
 359
 360 /* Set timer TIMERID to VALUE, returning old value in OVLAUE.  */
 361 extern int timer_settime (timer_t __timerid, int __flags,
 362                           __const struct itimerspec *__restrict __value,
 363                           struct itimerspec *__restrict __ovalue) __THROW;
 364
 365 /* Get current value of timer TIMERID and store it in VLAUE.  */
 366 extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
 367      __THROW;
 368
 369 /* Get expiration overrun for timer TIMERID.  */
 370 extern int timer_getoverrun (timer_t __timerid) __THROW;
 371 # endif
 372
 373
 374 # ifdef __USE_XOPEN_EXTENDED
 375 /* Set to one of the following values to indicate an error.
 376      1  the DATEMSK environment variable is null or undefined,
 377      2  the template file cannot be opened for reading,
 378      3  failed to get file status information,
 379      4  the template file is not a regular file,
 380      5  an error is encountered while reading the template file,
 381      6  memory allication failed (not enough memory available),
 382      7  there is no line in the template that matches the input,
 383      8  invalid input specification Example: February 31 or a time is
 384         specified that can not be represented in a time_t (representing
 385         the time in seconds since 00:00:00 UTC, January 1, 1970) */
 386 extern int getdate_err;
 387
 388 /* Parse the given string as a date specification and return a value
 389    representing the value.  The templates from the file identified by
 390    the environment variable DATEMSK are used.  In case of an error
 391    `getdate_err' is set.
 392
 393    This function is a possible cancellation points and therefore not
 394    marked with __THROW.  */
 395 extern struct tm *getdate (__const char *__string);
 396 # endif
 397
 398 # ifdef __USE_GNU
 399 /* Since `getdate' is not reentrant because of the use of `getdate_err'
 400    and the static buffer to return the result in, we provide a thread-safe
 401    variant.  The functionality is the same.  The result is returned in
 402    the buffer pointed to by RESBUFP and in case of an error the return
 403    value is != 0 with the same values as given above for `getdate_err'.
 404
 405    This function is not part of POSIX and therefore no official
 406    cancellation point.  But due to similarity with an POSIX interface
 407    or due to the implementation it is a cancellation point and
 408    therefore not marked with __THROW.  */
 409 extern int getdate_r (__const char *__restrict __string,
 410                       struct tm *__restrict __resbufp);
 411 # endif
 412
 413 __END_DECLS
 414
 415 #endif /* <time.h> included.  */
 416
 417 #endif /* <time.h> not already included.  */