time/time.h

   1 /* Copyright (C) 1991-2003,2006,2009 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 # include <bits/types.h>        /* This defines __time_t for us.  */
 117
 118 /* POSIX.1b structure for a time value.  This is like a `struct timeval' but
 119    has nanoseconds instead of microseconds.  */
 120 struct timespec
 121   {
 122     __time_t tv_sec;            /* Seconds.  */
 123     long int tv_nsec;           /* Nanoseconds.  */
 124   };
 125
 126 #endif /* timespec not defined and <time.h> or need timespec.  */
 127 #undef  __need_timespec
 128
 129
 130 #ifdef  _TIME_H
 131 __BEGIN_NAMESPACE_STD
 132 /* Used by other time functions.  */
 133 struct tm
 134 {
 135   int tm_sec;                   /* Seconds.     [0-60] (1 leap second) */
 136   int tm_min;                   /* Minutes.     [0-59] */
 137   int tm_hour;                  /* Hours.       [0-23] */
 138   int tm_mday;                  /* Day.         [1-31] */
 139   int tm_mon;                   /* Month.       [0-11] */
 140   int tm_year;                  /* Year - 1900.  */
 141   int tm_wday;                  /* Day of week. [0-6] */
 142   int tm_yday;                  /* Days in year.[0-365] */
 143   int tm_isdst;                 /* DST.         [-1/0/1]*/
 144
 145 #ifdef  __USE_BSD
 146   long int tm_gmtoff;           /* Seconds east of UTC.  */
 147   __const char *tm_zone;        /* Timezone abbreviation.  */
 148 #else
 149   long int __tm_gmtoff;         /* Seconds east of UTC.  */
 150   __const char *__tm_zone;      /* Timezone abbreviation.  */
 151 #endif
 152 };
 153 __END_NAMESPACE_STD
 154 #if defined __USE_XOPEN || defined __USE_POSIX || defined __USE_MISC
 155 __USING_NAMESPACE_STD(tm)
 156 #endif
 157
 158
 159 #ifdef __USE_POSIX199309
 160 /* POSIX.1b structure for timer start values and intervals.  */
 161 struct itimerspec
 162   {
 163     struct timespec it_interval;
 164     struct timespec it_value;
 165   };
 166
 167 /* We can use a simple forward declaration.  */
 168 struct sigevent;
 169
 170 #endif  /* POSIX.1b */
 171
 172 #ifdef __USE_XOPEN2K
 173 # ifndef __pid_t_defined
 174 typedef __pid_t pid_t;
 175 #  define __pid_t_defined
 176 # endif
 177 #endif
 178
 179
 180 __BEGIN_NAMESPACE_STD
 181 /* Time used by the program so far (user time + system time).
 182    The result / CLOCKS_PER_SECOND is program time in seconds.  */
 183 extern clock_t clock (void) __THROW;
 184
 185 /* Return the current time and put it in *TIMER if TIMER is not NULL.  */
 186 extern time_t time (time_t *__timer) __THROW;
 187
 188 /* Return the difference between TIME1 and TIME0.  */
 189 extern double difftime (time_t __time1, time_t __time0)
 190      __THROW __attribute__ ((__const__));
 191
 192 /* Return the `time_t' representation of TP and normalize TP.  */
 193 extern time_t mktime (struct tm *__tp) __THROW;
 194
 195
 196 /* Format TP into S according to FORMAT.
 197    Write no more than MAXSIZE characters and return the number
 198    of characters written, or 0 if it would exceed MAXSIZE.  */
 199 extern size_t strftime (char *__restrict __s, size_t __maxsize,
 200                         __const char *__restrict __format,
 201                         __const struct tm *__restrict __tp) __THROW;
 202 __END_NAMESPACE_STD
 203
 204 # ifdef __USE_XOPEN
 205 /* Parse S according to FORMAT and store binary time information in TP.
 206    The return value is a pointer to the first unparsed character in S.  */
 207 extern char *strptime (__const char *__restrict __s,
 208                        __const char *__restrict __fmt, struct tm *__tp)
 209      __THROW;
 210 # endif
 211
 212 # ifdef __USE_XOPEN2K8
 213 /* Similar to the two functions above but take the information from
 214    the provided locale and not the global locale.  */
 215 # include <xlocale.h>
 216
 217 extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
 218                           __const char *__restrict __format,
 219                           __const struct tm *__restrict __tp,
 220                           __locale_t __loc) __THROW;
 221 # endif
 222
 223 # ifdef __USE_GNU
 224 extern char *strptime_l (__const char *__restrict __s,
 225                          __const char *__restrict __fmt, struct tm *__tp,
 226                          __locale_t __loc) __THROW;
 227 # endif
 228
 229
 230 __BEGIN_NAMESPACE_STD
 231 /* Return the `struct tm' representation of *TIMER
 232    in Universal Coordinated Time (aka Greenwich Mean Time).  */
 233 extern struct tm *gmtime (__const time_t *__timer) __THROW;
 234
 235 /* Return the `struct tm' representation
 236    of *TIMER in the local timezone.  */
 237 extern struct tm *localtime (__const time_t *__timer) __THROW;
 238 __END_NAMESPACE_STD
 239
 240 # if defined __USE_POSIX || defined __USE_MISC
 241 /* Return the `struct tm' representation of *TIMER in UTC,
 242    using *TP to store the result.  */
 243 extern struct tm *gmtime_r (__const time_t *__restrict __timer,
 244                             struct tm *__restrict __tp) __THROW;
 245
 246 /* Return the `struct tm' representation of *TIMER in local time,
 247    using *TP to store the result.  */
 248 extern struct tm *localtime_r (__const time_t *__restrict __timer,
 249                                struct tm *__restrict __tp) __THROW;
 250 # endif /* POSIX or misc */
 251
 252 __BEGIN_NAMESPACE_STD
 253 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 254    that is the representation of TP in this format.  */
 255 extern char *asctime (__const struct tm *__tp) __THROW;
 256
 257 /* Equivalent to `asctime (localtime (timer))'.  */
 258 extern char *ctime (__const time_t *__timer) __THROW;
 259 __END_NAMESPACE_STD
 260
 261 # if defined __USE_POSIX || defined __USE_MISC
 262 /* Reentrant versions of the above functions.  */
 263
 264 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 265    that is the representation of TP in this format.  */
 266 extern char *asctime_r (__const struct tm *__restrict __tp,
 267                         char *__restrict __buf) __THROW;
 268
 269 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'.  */
 270 extern char *ctime_r (__const time_t *__restrict __timer,
 271                       char *__restrict __buf) __THROW;
 272 # endif /* POSIX or misc */
 273
 274
 275 /* Defined in localtime.c.  */
 276 extern char *__tzname[2];       /* Current timezone names.  */
 277 extern int __daylight;          /* If daylight-saving time is ever in use.  */
 278 extern long int __timezone;     /* Seconds west of UTC.  */
 279
 280
 281 # ifdef __USE_POSIX
 282 /* Same as above.  */
 283 extern char *tzname[2];
 284
 285 /* Set time conversion information from the TZ environment variable.
 286    If TZ is not defined, a locale-dependent default is used.  */
 287 extern void tzset (void) __THROW;
 288 # endif
 289
 290 # if defined __USE_SVID || defined __USE_XOPEN
 291 extern int daylight;
 292 extern long int timezone;
 293 # endif
 294
 295 # ifdef __USE_SVID
 296 /* Set the system time to *WHEN.
 297    This call is restricted to the superuser.  */
 298 extern int stime (__const time_t *__when) __THROW;
 299 # endif
 300
 301
 302 /* Nonzero if YEAR is a leap year (every 4 years,
 303    except every 100th isn't, and every 400th is).  */
 304 # define __isleap(year) \
 305   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 306
 307
 308 # ifdef __USE_MISC
 309 /* Miscellaneous functions many Unices inherited from the public domain
 310    localtime package.  These are included only for compatibility.  */
 311
 312 /* Like `mktime', but for TP represents Universal Time, not local time.  */
 313 extern time_t timegm (struct tm *__tp) __THROW;
 314
 315 /* Another name for `mktime'.  */
 316 extern time_t timelocal (struct tm *__tp) __THROW;
 317
 318 /* Return the number of days in YEAR.  */
 319 extern int dysize (int __year) __THROW  __attribute__ ((__const__));
 320 # endif
 321
 322
 323 # ifdef __USE_POSIX199309
 324 /* Pause execution for a number of nanoseconds.
 325
 326    This function is a cancellation point and therefore not marked with
 327    __THROW.  */
 328 extern int nanosleep (__const struct timespec *__requested_time,
 329                       struct timespec *__remaining);
 330
 331
 332 /* Get resolution of clock CLOCK_ID.  */
 333 extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
 334
 335 /* Get current value of clock CLOCK_ID and store it in TP.  */
 336 extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
 337
 338 /* Set clock CLOCK_ID to value TP.  */
 339 extern int clock_settime (clockid_t __clock_id, __const struct timespec *__tp)
 340      __THROW;
 341
 342 #  ifdef __USE_XOPEN2K
 343 /* High-resolution sleep with the specified clock.
 344
 345    This function is a cancellation point and therefore not marked with
 346    __THROW.  */
 347 extern int clock_nanosleep (clockid_t __clock_id, int __flags,
 348                             __const struct timespec *__req,
 349                             struct timespec *__rem);
 350
 351 /* Return clock ID for CPU-time clock.  */
 352 extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
 353 #  endif
 354
 355
 356 /* Create new per-process timer using CLOCK_ID.  */
 357 extern int timer_create (clockid_t __clock_id,
 358                          struct sigevent *__restrict __evp,
 359                          timer_t *__restrict __timerid) __THROW;
 360
 361 /* Delete timer TIMERID.  */
 362 extern int timer_delete (timer_t __timerid) __THROW;
 363
 364 /* Set timer TIMERID to VALUE, returning old value in OVLAUE.  */
 365 extern int timer_settime (timer_t __timerid, int __flags,
 366                           __const struct itimerspec *__restrict __value,
 367                           struct itimerspec *__restrict __ovalue) __THROW;
 368
 369 /* Get current value of timer TIMERID and store it in VLAUE.  */
 370 extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
 371      __THROW;
 372
 373 /* Get expiration overrun for timer TIMERID.  */
 374 extern int timer_getoverrun (timer_t __timerid) __THROW;
 375 # endif
 376
 377
 378 # ifdef __USE_XOPEN_EXTENDED
 379 /* Set to one of the following values to indicate an error.
 380      1  the DATEMSK environment variable is null or undefined,
 381      2  the template file cannot be opened for reading,
 382      3  failed to get file status information,
 383      4  the template file is not a regular file,
 384      5  an error is encountered while reading the template file,
 385      6  memory allication failed (not enough memory available),
 386      7  there is no line in the template that matches the input,
 387      8  invalid input specification Example: February 31 or a time is
 388         specified that can not be represented in a time_t (representing
 389         the time in seconds since 00:00:00 UTC, January 1, 1970) */
 390 extern int getdate_err;
 391
 392 /* Parse the given string as a date specification and return a value
 393    representing the value.  The templates from the file identified by
 394    the environment variable DATEMSK are used.  In case of an error
 395    `getdate_err' is set.
 396
 397    This function is a possible cancellation points and therefore not
 398    marked with __THROW.  */
 399 extern struct tm *getdate (__const char *__string);
 400 # endif
 401
 402 # ifdef __USE_GNU
 403 /* Since `getdate' is not reentrant because of the use of `getdate_err'
 404    and the static buffer to return the result in, we provide a thread-safe
 405    variant.  The functionality is the same.  The result is returned in
 406    the buffer pointed to by RESBUFP and in case of an error the return
 407    value is != 0 with the same values as given above for `getdate_err'.
 408
 409    This function is not part of POSIX and therefore no official
 410    cancellation point.  But due to similarity with an POSIX interface
 411    or due to the implementation it is a cancellation point and
 412    therefore not marked with __THROW.  */
 413 extern int getdate_r (__const char *__restrict __string,
 414                       struct tm *__restrict __resbufp);
 415 # endif
 416
 417 __END_DECLS
 418
 419 #endif /* <time.h> included.  */
 420
 421 #endif /* <time.h> not already included.  */