time/time.h

   1 /* Copyright (C) 1991-2022 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    <https://www.gnu.org/licenses/>.  */
  17
  18 /*
  19  *      ISO C99 Standard: 7.23 Date and time    <time.h>
  20  */
  21
  22 #ifndef _TIME_H
  23 #define _TIME_H 1
  24
  25 #include <features.h>
  26
  27 #define __need_size_t
  28 #define __need_NULL
  29 #include <stddef.h>
  30
  31 /* This defines CLOCKS_PER_SEC, which is the number of processor clock
  32    ticks per second, and possibly a number of other constants.   */
  33 #include <bits/time.h>
  34
  35 /* Many of the typedefs and structs whose official home is this header
  36    may also need to be defined by other headers.  */
  37 #include <bits/types/clock_t.h>
  38 #include <bits/types/time_t.h>
  39 #include <bits/types/struct_tm.h>
  40
  41 #if defined __USE_POSIX199309 || defined __USE_ISOC11
  42 # include <bits/types/struct_timespec.h>
  43 #endif
  44
  45 #ifdef __USE_POSIX199309
  46 # include <bits/types/clockid_t.h>
  47 # include <bits/types/timer_t.h>
  48 # include <bits/types/struct_itimerspec.h>
  49 struct sigevent;
  50 #endif
  51
  52 #ifdef __USE_XOPEN2K
  53 # ifndef __pid_t_defined
  54 typedef __pid_t pid_t;
  55 #  define __pid_t_defined
  56 # endif
  57 #endif
  58
  59 #ifdef __USE_XOPEN2K8
  60 # include <bits/types/locale_t.h>
  61 #endif
  62
  63 #ifdef __USE_ISOC11
  64 /* Time base values for timespec_get.  */
  65 # define TIME_UTC 1
  66 #endif
  67
  68 __BEGIN_DECLS
  69
  70 /* Time used by the program so far (user time + system time).
  71    The result / CLOCKS_PER_SEC is program time in seconds.  */
  72 extern clock_t clock (void) __THROW;
  73
  74 #ifndef __USE_TIME_BITS64
  75 /* Return the current time and put it in *TIMER if TIMER is not NULL.  */
  76 extern time_t time (time_t *__timer) __THROW;
  77
  78 /* Return the difference between TIME1 and TIME0.  */
  79 extern double difftime (time_t __time1, time_t __time0)
  80      __THROW __attribute__ ((__const__));
  81
  82 /* Return the `time_t' representation of TP and normalize TP.  */
  83 extern time_t mktime (struct tm *__tp) __THROW;
  84 #else
  85 # ifdef __REDIRECT_NTH
  86 extern time_t __REDIRECT_NTH (time, (time_t *__timer), __time64);
  87 extern double __REDIRECT_NTH (difftime, (time_t __time1, time_t __time0),
  88                               __difftime64) __attribute__ ((__const__));
  89 extern time_t __REDIRECT_NTH (mktime, (struct tm *__tp), __mktime64);
  90 # else
  91 #  define time __time64
  92 #  define difftime __difftime64
  93 #  define mktime __mktime64
  94 # endif
  95 #endif
  96
  97 /* Format TP into S according to FORMAT.
  98    Write no more than MAXSIZE characters and return the number
  99    of characters written, or 0 if it would exceed MAXSIZE.  */
 100 extern size_t strftime (char *__restrict __s, size_t __maxsize,
 101                         const char *__restrict __format,
 102                         const struct tm *__restrict __tp) __THROW;
 103
 104 #ifdef __USE_XOPEN
 105 /* Parse S according to FORMAT and store binary time information in TP.
 106    The return value is a pointer to the first unparsed character in S.  */
 107 extern char *strptime (const char *__restrict __s,
 108                        const char *__restrict __fmt, struct tm *__tp)
 109      __THROW;
 110 #endif
 111
 112 #ifdef __USE_XOPEN2K8
 113 /* Similar to the two functions above but take the information from
 114    the provided locale and not the global locale.  */
 115
 116 extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
 117                           const char *__restrict __format,
 118                           const struct tm *__restrict __tp,
 119                           locale_t __loc) __THROW;
 120 #endif
 121
 122 #ifdef __USE_GNU
 123 extern char *strptime_l (const char *__restrict __s,
 124                          const char *__restrict __fmt, struct tm *__tp,
 125                          locale_t __loc) __THROW;
 126 #endif
 127
 128
 129 #ifndef __USE_TIME_BITS64
 130 /* Return the `struct tm' representation of *TIMER
 131    in Universal Coordinated Time (aka Greenwich Mean Time).  */
 132 extern struct tm *gmtime (const time_t *__timer) __THROW;
 133
 134 /* Return the `struct tm' representation
 135    of *TIMER in the local timezone.  */
 136 extern struct tm *localtime (const time_t *__timer) __THROW;
 137
 138 #else
 139 # ifdef __REDIRECT_NTH
 140 extern struct tm*__REDIRECT_NTH (gmtime, (const time_t *__timer), __gmtime64);
 141 extern struct tm *__REDIRECT_NTH (localtime, (const time_t *__timer),
 142                                   __localtime64);
 143 # else
 144 #  define gmtime __gmtime64
 145 #  define localtime __localtime64
 146 # endif
 147 #endif
 148
 149
 150 #if defined __USE_POSIX || __GLIBC_USE (ISOC2X)
 151 # ifndef __USE_TIME_BITS64
 152 /* Return the `struct tm' representation of *TIMER in UTC,
 153    using *TP to store the result.  */
 154 extern struct tm *gmtime_r (const time_t *__restrict __timer,
 155                             struct tm *__restrict __tp) __THROW;
 156
 157 /* Return the `struct tm' representation of *TIMER in local time,
 158    using *TP to store the result.  */
 159 extern struct tm *localtime_r (const time_t *__restrict __timer,
 160                                struct tm *__restrict __tp) __THROW;
 161 # else
 162 #  ifdef __REDIRECT_NTH
 163 extern struct tm*__REDIRECT_NTH (gmtime_r, (const time_t *__restrict __timer,
 164                                             struct tm *__restrict __tp),
 165                                  __gmtime64_r);
 166
 167 extern struct tm*__REDIRECT_NTH (localtime_r, (const time_t *__restrict __t,
 168                                                struct tm *__restrict __tp),
 169                                  __localtime64_r);
 170 #  else
 171 #   define gmtime_r __gmtime64_r
 172 #   define localtime_r __localtime_r
 173 #  endif
 174 # endif
 175 #endif  /* POSIX || C2X */
 176
 177 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 178    that is the representation of TP in this format.  */
 179 extern char *asctime (const struct tm *__tp) __THROW;
 180
 181 /* Equivalent to `asctime (localtime (timer))'.  */
 182 #ifndef __USE_TIME_BITS64
 183 extern char *ctime (const time_t *__timer) __THROW;
 184 #else
 185 # ifdef __REDIRECT_NTH
 186 extern char *__REDIRECT_NTH (ctime, (const time_t *__timer), __ctime64);
 187 # else
 188 #  define ctime __ctime64
 189 # endif
 190 #endif
 191
 192 #ifdef __USE_POSIX
 193 /* Reentrant versions of the above functions.  */
 194
 195 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 196    that is the representation of TP in this format.  */
 197 extern char *asctime_r (const struct tm *__restrict __tp,
 198                         char *__restrict __buf) __THROW;
 199
 200 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'.  */
 201 #ifndef __USE_TIME_BITS64
 202 extern char *ctime_r (const time_t *__restrict __timer,
 203                       char *__restrict __buf) __THROW;
 204 #else
 205 # ifdef __REDIRECT_NTH
 206 extern char *__REDIRECT_NTH (ctime_r, (const time_t *__restrict __timer,
 207                                        char *__restrict __buf), __ctime64_r);
 208 # else
 209 #  define ctime_r __ctime64_r
 210 # endif
 211 #endif
 212
 213 #endif  /* POSIX */
 214
 215
 216 /* Defined in localtime.c.  */
 217 extern char *__tzname[2];       /* Current timezone names.  */
 218 extern int __daylight;          /* If daylight-saving time is ever in use.  */
 219 extern long int __timezone;     /* Seconds west of UTC.  */
 220
 221
 222 #ifdef  __USE_POSIX
 223 /* Same as above.  */
 224 extern char *tzname[2];
 225
 226 /* Set time conversion information from the TZ environment variable.
 227    If TZ is not defined, a locale-dependent default is used.  */
 228 extern void tzset (void) __THROW;
 229 #endif
 230
 231 #if defined __USE_MISC || defined __USE_XOPEN
 232 extern int daylight;
 233 extern long int timezone;
 234 #endif
 235
 236
 237 /* Nonzero if YEAR is a leap year (every 4 years,
 238    except every 100th isn't, and every 400th is).  */
 239 #define __isleap(year)  \
 240   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 241
 242
 243 #ifdef __USE_MISC
 244 /* Miscellaneous functions many Unices inherited from the public domain
 245    localtime package.  These are included only for compatibility.  */
 246
 247 #ifndef __USE_TIME_BITS64
 248 /* Like `mktime', but for TP represents Universal Time, not local time.  */
 249 extern time_t timegm (struct tm *__tp) __THROW;
 250 /* Another name for `mktime'.  */
 251 extern time_t timelocal (struct tm *__tp) __THROW;
 252 #else
 253 # ifdef __REDIRECT_NTH
 254 extern time_t __REDIRECT_NTH (timegm, (struct tm *__tp), __timegm64);
 255 extern time_t __REDIRECT_NTH (timelocal, (struct tm *__tp), __mktime64);
 256 # else
 257 #  define timegm __timegm64
 258 # endif
 259 #endif
 260
 261 /* Return the number of days in YEAR.  */
 262 extern int dysize (int __year) __THROW  __attribute__ ((__const__));
 263 #endif
 264
 265
 266 #ifdef __USE_POSIX199309
 267 # ifndef __USE_TIME_BITS64
 268 /* Pause execution for a number of nanoseconds.
 269
 270    This function is a cancellation point and therefore not marked with
 271    __THROW.  */
 272 extern int nanosleep (const struct timespec *__requested_time,
 273                       struct timespec *__remaining);
 274
 275 /* Get resolution of clock CLOCK_ID.  */
 276 extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
 277
 278 /* Get current value of clock CLOCK_ID and store it in TP.  */
 279 extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
 280
 281 /* Set clock CLOCK_ID to value TP.  */
 282 extern int clock_settime (clockid_t __clock_id, const struct timespec *__tp)
 283      __THROW;
 284 # else
 285 #  ifdef __REDIRECT
 286 extern int __REDIRECT (nanosleep, (const struct timespec *__requested_time,
 287                                    struct timespec *__remaining),
 288                        __nanosleep64);
 289 extern int __REDIRECT_NTH (clock_getres, (clockid_t __clock_id,
 290                                           struct timespec *__res),
 291                            __clock_getres64);
 292 extern int __REDIRECT_NTH (clock_gettime, (clockid_t __clock_id, struct
 293                                            timespec *__tp), __clock_gettime64);
 294 extern int __REDIRECT_NTH (clock_settime, (clockid_t __clock_id, const struct
 295                                            timespec *__tp), __clock_settime64);
 296 #  else
 297 #   define nanosleep __nanosleep64
 298 #   define clock_getres __clock_getres64
 299 #   define clock_gettime __clock_gettime64
 300 #   define clock_settime __clock_settime64
 301 #  endif
 302 # endif
 303
 304
 305 # ifdef __USE_XOPEN2K
 306 /* High-resolution sleep with the specified clock.
 307
 308    This function is a cancellation point and therefore not marked with
 309    __THROW.  */
 310 #  ifndef __USE_TIME_BITS64
 311 extern int clock_nanosleep (clockid_t __clock_id, int __flags,
 312                             const struct timespec *__req,
 313                             struct timespec *__rem);
 314 #  else
 315 #   ifdef __REDIRECT
 316 extern int __REDIRECT (clock_nanosleep, (clockid_t __clock_id, int __flags,
 317                                          const struct timespec *__req,
 318                                          struct timespec *__rem),
 319                        __clock_nanosleep_time64);
 320 #   else
 321 #    define clock_nanosleep __clock_nanosleep_time64
 322 #   endif
 323 #  endif
 324
 325 /* Return clock ID for CPU-time clock.  */
 326 extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
 327 # endif
 328
 329
 330 /* Create new per-process timer using CLOCK_ID.  */
 331 extern int timer_create (clockid_t __clock_id,
 332                          struct sigevent *__restrict __evp,
 333                          timer_t *__restrict __timerid) __THROW;
 334
 335 /* Delete timer TIMERID.  */
 336 extern int timer_delete (timer_t __timerid) __THROW;
 337
 338 /* Set timer TIMERID to VALUE, returning old value in OVALUE.  */
 339 # ifndef __USE_TIME_BITS64
 340 extern int timer_settime (timer_t __timerid, int __flags,
 341                           const struct itimerspec *__restrict __value,
 342                           struct itimerspec *__restrict __ovalue) __THROW;
 343
 344 /* Get current value of timer TIMERID and store it in VALUE.  */
 345 extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
 346      __THROW;
 347 # else
 348 #  ifdef __REDIRECT_NTH
 349 extern int __REDIRECT_NTH (timer_settime, (timer_t __timerid, int __flags,
 350      const struct itimerspec *__restrict __value,
 351      struct itimerspec *__restrict __ovalue),
 352                           __timer_settime64);
 353
 354 extern int __REDIRECT_NTH (timer_gettime, (timer_t __timerid,
 355                                            struct itimerspec *__value),
 356                            __timer_gettime64);
 357 #  else
 358 #   define timer_settime __timer_settime64
 359 #   define timer_gettime __timer_gettime64
 360 #  endif
 361 # endif
 362
 363 /* Get expiration overrun for timer TIMERID.  */
 364 extern int timer_getoverrun (timer_t __timerid) __THROW;
 365 #endif
 366
 367
 368 #ifdef __USE_ISOC11
 369 # ifndef __USE_TIME_BITS64
 370 /* Set TS to calendar time based in time base BASE.  */
 371 extern int timespec_get (struct timespec *__ts, int __base)
 372      __THROW __nonnull ((1));
 373 # else
 374 #  ifdef __REDIRECT_NTH
 375 extern int __REDIRECT_NTH (timespec_get, (struct timespec *__ts, int __base),
 376                            __timespec_get64) __nonnull ((1));
 377 #  else
 378 #   define timespec_get __timespec_get64
 379 #  endif
 380 # endif
 381 #endif
 382
 383
 384 #if __GLIBC_USE (ISOC2X)
 385 # ifndef __USE_TIME_BITS64
 386 /* Set TS to resolution of time base BASE.  */
 387 extern int timespec_getres (struct timespec *__ts, int __base)
 388      __THROW;
 389 # else
 390 #  ifdef __REDIRECT_NTH
 391 extern int __REDIRECT_NTH (timespec_getres, (struct timespec *__ts,
 392                                              int __base),
 393                            __timespec_getres64);
 394 #  else
 395 #   define timespec_getres __timespec_getres64
 396 #  endif
 397 # endif
 398 #endif
 399
 400
 401 #ifdef __USE_XOPEN_EXTENDED
 402 /* Set to one of the following values to indicate an error.
 403      1  the DATEMSK environment variable is null or undefined,
 404      2  the template file cannot be opened for reading,
 405      3  failed to get file status information,
 406      4  the template file is not a regular file,
 407      5  an error is encountered while reading the template file,
 408      6  memory allication failed (not enough memory available),
 409      7  there is no line in the template that matches the input,
 410      8  invalid input specification Example: February 31 or a time is
 411         specified that can not be represented in a time_t (representing
 412         the time in seconds since 00:00:00 UTC, January 1, 1970) */
 413 extern int getdate_err;
 414
 415 /* Parse the given string as a date specification and return a value
 416    representing the value.  The templates from the file identified by
 417    the environment variable DATEMSK are used.  In case of an error
 418    `getdate_err' is set.
 419
 420    This function is a possible cancellation point and therefore not
 421    marked with __THROW.  */
 422 extern struct tm *getdate (const char *__string);
 423 #endif
 424
 425 #ifdef __USE_GNU
 426 /* Since `getdate' is not reentrant because of the use of `getdate_err'
 427    and the static buffer to return the result in, we provide a thread-safe
 428    variant.  The functionality is the same.  The result is returned in
 429    the buffer pointed to by RESBUFP and in case of an error the return
 430    value is != 0 with the same values as given above for `getdate_err'.
 431
 432    This function is not part of POSIX and therefore no official
 433    cancellation point.  But due to similarity with an POSIX interface
 434    or due to the implementation it is a cancellation point and
 435    therefore not marked with __THROW.  */
 436 extern int getdate_r (const char *__restrict __string,
 437                       struct tm *__restrict __resbufp);
 438 #endif
 439
 440 __END_DECLS
 441
 442 #endif /* time.h.  */