time/time.h

   1 /* Copyright (C) 1991-2015 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 /*
  19  *      ISO C99 Standard: 7.23 Date and time    <time.h>
  20  */
  21
  22 #ifndef _TIME_H
  23
  24 #if (! defined __need_time_t && !defined __need_clock_t && \
  25      ! defined __need_timespec)
  26 # define _TIME_H        1
  27 # include <features.h>
  28
  29 __BEGIN_DECLS
  30
  31 #endif
  32
  33 #ifdef  _TIME_H
  34 /* Get size_t and NULL from <stddef.h>.  */
  35 # define __need_size_t
  36 # define __need_NULL
  37 # include <stddef.h>
  38
  39 /* This defines CLOCKS_PER_SEC, which is the number of processor clock
  40    ticks per second.  */
  41 # include <bits/time.h>
  42
  43 /* This is the obsolete POSIX.1-1988 name for the same constant.  */
  44 # if !defined __STRICT_ANSI__ && !defined __USE_XOPEN2K
  45 #  ifndef CLK_TCK
  46 #   define CLK_TCK      CLOCKS_PER_SEC
  47 #  endif
  48 # endif
  49
  50 #endif /* <time.h> included.  */
  51
  52 #if !defined __clock_t_defined && (defined _TIME_H || defined __need_clock_t)
  53 # define __clock_t_defined      1
  54
  55 # include <bits/types.h>
  56
  57 __BEGIN_NAMESPACE_STD
  58 /* Returned by `clock'.  */
  59 typedef __clock_t clock_t;
  60 __END_NAMESPACE_STD
  61 #if defined __USE_XOPEN || defined __USE_POSIX
  62 __USING_NAMESPACE_STD(clock_t)
  63 #endif
  64
  65 #endif /* clock_t not defined and <time.h> or need clock_t.  */
  66 #undef  __need_clock_t
  67
  68 #if !defined __time_t_defined && (defined _TIME_H || defined __need_time_t)
  69 # define __time_t_defined       1
  70
  71 # include <bits/types.h>
  72
  73 __BEGIN_NAMESPACE_STD
  74 /* Returned by `time'.  */
  75 typedef __time_t time_t;
  76 __END_NAMESPACE_STD
  77 #ifdef __USE_POSIX
  78 __USING_NAMESPACE_STD(time_t)
  79 #endif
  80
  81 #endif /* time_t not defined and <time.h> or need time_t.  */
  82 #undef  __need_time_t
  83
  84 #if !defined __clockid_t_defined && \
  85    ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_clockid_t)
  86 # define __clockid_t_defined    1
  87
  88 # include <bits/types.h>
  89
  90 /* Clock ID used in clock and timer functions.  */
  91 typedef __clockid_t clockid_t;
  92
  93 #endif /* clockid_t not defined and <time.h> or need clockid_t.  */
  94 #undef  __clockid_time_t
  95
  96 #if !defined __timer_t_defined && \
  97     ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_timer_t)
  98 # define __timer_t_defined      1
  99
 100 # include <bits/types.h>
 101
 102 /* Timer ID returned by `timer_create'.  */
 103 typedef __timer_t timer_t;
 104
 105 #endif /* timer_t not defined and <time.h> or need timer_t.  */
 106 #undef  __need_timer_t
 107
 108
 109 #if (!defined __timespec_defined                                        \
 110      && ((defined _TIME_H                                               \
 111           && (defined __USE_POSIX199309                                 \
 112               || defined __USE_ISOC11))                                 \
 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     __syscall_slong_t 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_MISC
 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
 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 # ifdef __USE_ISOC11
 181 /* Time base values for timespec_get.  */
 182 # define TIME_UTC 1
 183 # endif
 184
 185
 186 __BEGIN_NAMESPACE_STD
 187 /* Time used by the program so far (user time + system time).
 188    The result / CLOCKS_PER_SECOND is program time in seconds.  */
 189 extern clock_t clock (void) __THROW;
 190
 191 /* Return the current time and put it in *TIMER if TIMER is not NULL.  */
 192 extern time_t time (time_t *__timer) __THROW;
 193
 194 /* Return the difference between TIME1 and TIME0.  */
 195 extern double difftime (time_t __time1, time_t __time0)
 196      __THROW __attribute__ ((__const__));
 197
 198 /* Return the `time_t' representation of TP and normalize TP.  */
 199 extern time_t mktime (struct tm *__tp) __THROW;
 200
 201
 202 /* Format TP into S according to FORMAT.
 203    Write no more than MAXSIZE characters and return the number
 204    of characters written, or 0 if it would exceed MAXSIZE.  */
 205 extern size_t strftime (char *__restrict __s, size_t __maxsize,
 206                         const char *__restrict __format,
 207                         const struct tm *__restrict __tp) __THROW;
 208 __END_NAMESPACE_STD
 209
 210 # ifdef __USE_XOPEN
 211 /* Parse S according to FORMAT and store binary time information in TP.
 212    The return value is a pointer to the first unparsed character in S.  */
 213 extern char *strptime (const char *__restrict __s,
 214                        const char *__restrict __fmt, struct tm *__tp)
 215      __THROW;
 216 # endif
 217
 218 # ifdef __USE_XOPEN2K8
 219 /* Similar to the two functions above but take the information from
 220    the provided locale and not the global locale.  */
 221 # include <xlocale.h>
 222
 223 extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
 224                           const char *__restrict __format,
 225                           const struct tm *__restrict __tp,
 226                           __locale_t __loc) __THROW;
 227 # endif
 228
 229 # ifdef __USE_GNU
 230 extern char *strptime_l (const char *__restrict __s,
 231                          const char *__restrict __fmt, struct tm *__tp,
 232                          __locale_t __loc) __THROW;
 233 # endif
 234
 235
 236 __BEGIN_NAMESPACE_STD
 237 /* Return the `struct tm' representation of *TIMER
 238    in Universal Coordinated Time (aka Greenwich Mean Time).  */
 239 extern struct tm *gmtime (const time_t *__timer) __THROW;
 240
 241 /* Return the `struct tm' representation
 242    of *TIMER in the local timezone.  */
 243 extern struct tm *localtime (const time_t *__timer) __THROW;
 244 __END_NAMESPACE_STD
 245
 246 # ifdef __USE_POSIX
 247 /* Return the `struct tm' representation of *TIMER in UTC,
 248    using *TP to store the result.  */
 249 extern struct tm *gmtime_r (const time_t *__restrict __timer,
 250                             struct tm *__restrict __tp) __THROW;
 251
 252 /* Return the `struct tm' representation of *TIMER in local time,
 253    using *TP to store the result.  */
 254 extern struct tm *localtime_r (const time_t *__restrict __timer,
 255                                struct tm *__restrict __tp) __THROW;
 256 # endif /* POSIX */
 257
 258 __BEGIN_NAMESPACE_STD
 259 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 260    that is the representation of TP in this format.  */
 261 extern char *asctime (const struct tm *__tp) __THROW;
 262
 263 /* Equivalent to `asctime (localtime (timer))'.  */
 264 extern char *ctime (const time_t *__timer) __THROW;
 265 __END_NAMESPACE_STD
 266
 267 # ifdef __USE_POSIX
 268 /* Reentrant versions of the above functions.  */
 269
 270 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 271    that is the representation of TP in this format.  */
 272 extern char *asctime_r (const struct tm *__restrict __tp,
 273                         char *__restrict __buf) __THROW;
 274
 275 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'.  */
 276 extern char *ctime_r (const time_t *__restrict __timer,
 277                       char *__restrict __buf) __THROW;
 278 # endif /* POSIX */
 279
 280
 281 /* Defined in localtime.c.  */
 282 extern char *__tzname[2];       /* Current timezone names.  */
 283 extern int __daylight;          /* If daylight-saving time is ever in use.  */
 284 extern long int __timezone;     /* Seconds west of UTC.  */
 285
 286
 287 # ifdef __USE_POSIX
 288 /* Same as above.  */
 289 extern char *tzname[2];
 290
 291 /* Set time conversion information from the TZ environment variable.
 292    If TZ is not defined, a locale-dependent default is used.  */
 293 extern void tzset (void) __THROW;
 294 # endif
 295
 296 # if defined __USE_MISC || defined __USE_XOPEN
 297 extern int daylight;
 298 extern long int timezone;
 299 # endif
 300
 301 # ifdef __USE_MISC
 302 /* Set the system time to *WHEN.
 303    This call is restricted to the superuser.  */
 304 extern int stime (const time_t *__when) __THROW;
 305 # endif
 306
 307
 308 /* Nonzero if YEAR is a leap year (every 4 years,
 309    except every 100th isn't, and every 400th is).  */
 310 # define __isleap(year) \
 311   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 312
 313
 314 # ifdef __USE_MISC
 315 /* Miscellaneous functions many Unices inherited from the public domain
 316    localtime package.  These are included only for compatibility.  */
 317
 318 /* Like `mktime', but for TP represents Universal Time, not local time.  */
 319 extern time_t timegm (struct tm *__tp) __THROW;
 320
 321 /* Another name for `mktime'.  */
 322 extern time_t timelocal (struct tm *__tp) __THROW;
 323
 324 /* Return the number of days in YEAR.  */
 325 extern int dysize (int __year) __THROW  __attribute__ ((__const__));
 326 # endif
 327
 328
 329 # ifdef __USE_POSIX199309
 330 /* Pause execution for a number of nanoseconds.
 331
 332    This function is a cancellation point and therefore not marked with
 333    __THROW.  */
 334 extern int nanosleep (const struct timespec *__requested_time,
 335                       struct timespec *__remaining);
 336
 337
 338 /* Get resolution of clock CLOCK_ID.  */
 339 extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
 340
 341 /* Get current value of clock CLOCK_ID and store it in TP.  */
 342 extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
 343
 344 /* Set clock CLOCK_ID to value TP.  */
 345 extern int clock_settime (clockid_t __clock_id, const struct timespec *__tp)
 346      __THROW;
 347
 348 #  ifdef __USE_XOPEN2K
 349 /* High-resolution sleep with the specified clock.
 350
 351    This function is a cancellation point and therefore not marked with
 352    __THROW.  */
 353 extern int clock_nanosleep (clockid_t __clock_id, int __flags,
 354                             const struct timespec *__req,
 355                             struct timespec *__rem);
 356
 357 /* Return clock ID for CPU-time clock.  */
 358 extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
 359 #  endif
 360
 361
 362 /* Create new per-process timer using CLOCK_ID.  */
 363 extern int timer_create (clockid_t __clock_id,
 364                          struct sigevent *__restrict __evp,
 365                          timer_t *__restrict __timerid) __THROW;
 366
 367 /* Delete timer TIMERID.  */
 368 extern int timer_delete (timer_t __timerid) __THROW;
 369
 370 /* Set timer TIMERID to VALUE, returning old value in OVALUE.  */
 371 extern int timer_settime (timer_t __timerid, int __flags,
 372                           const struct itimerspec *__restrict __value,
 373                           struct itimerspec *__restrict __ovalue) __THROW;
 374
 375 /* Get current value of timer TIMERID and store it in VALUE.  */
 376 extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
 377      __THROW;
 378
 379 /* Get expiration overrun for timer TIMERID.  */
 380 extern int timer_getoverrun (timer_t __timerid) __THROW;
 381 # endif
 382
 383
 384 # ifdef __USE_ISOC11
 385 /* Set TS to calendar time based in time base BASE.  */
 386 extern int timespec_get (struct timespec *__ts, int __base)
 387      __THROW __nonnull ((1));
 388 # endif
 389
 390
 391 # ifdef __USE_XOPEN_EXTENDED
 392 /* Set to one of the following values to indicate an error.
 393      1  the DATEMSK environment variable is null or undefined,
 394      2  the template file cannot be opened for reading,
 395      3  failed to get file status information,
 396      4  the template file is not a regular file,
 397      5  an error is encountered while reading the template file,
 398      6  memory allication failed (not enough memory available),
 399      7  there is no line in the template that matches the input,
 400      8  invalid input specification Example: February 31 or a time is
 401         specified that can not be represented in a time_t (representing
 402         the time in seconds since 00:00:00 UTC, January 1, 1970) */
 403 extern int getdate_err;
 404
 405 /* Parse the given string as a date specification and return a value
 406    representing the value.  The templates from the file identified by
 407    the environment variable DATEMSK are used.  In case of an error
 408    `getdate_err' is set.
 409
 410    This function is a possible cancellation point and therefore not
 411    marked with __THROW.  */
 412 extern struct tm *getdate (const char *__string);
 413 # endif
 414
 415 # ifdef __USE_GNU
 416 /* Since `getdate' is not reentrant because of the use of `getdate_err'
 417    and the static buffer to return the result in, we provide a thread-safe
 418    variant.  The functionality is the same.  The result is returned in
 419    the buffer pointed to by RESBUFP and in case of an error the return
 420    value is != 0 with the same values as given above for `getdate_err'.
 421
 422    This function is not part of POSIX and therefore no official
 423    cancellation point.  But due to similarity with an POSIX interface
 424    or due to the implementation it is a cancellation point and
 425    therefore not marked with __THROW.  */
 426 extern int getdate_r (const char *__restrict __string,
 427                       struct tm *__restrict __resbufp);
 428 # endif
 429
 430 __END_DECLS
 431
 432 #endif /* <time.h> included.  */
 433
 434 #endif /* <time.h> not already included.  */