time/time.h

   1 /* Copyright (C) 1991,92,93,94,95,96,97,98 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 C Standard: 4.12 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 #endif /* <time.h> included.  */
  40
  41
  42
  43 #ifdef  _TIME_H
  44
  45 /* This defines CLOCKS_PER_SEC, which is the number of processor clock
  46    ticks per second.  */
  47 # include <bits/time.h>
  48
  49 /* This is the obsolete POSIX.1-1988 name for the same constant.  */
  50 # ifdef __USE_POSIX
  51 #  ifndef CLK_TCK
  52 #   define CLK_TCK      CLOCKS_PER_SEC
  53 #  endif
  54 # endif
  55
  56 #endif /* <time.h> included.  */
  57
  58
  59 #if !defined __clock_t_defined && (defined _TIME_H || defined __need_clock_t)
  60 # define __clock_t_defined      1
  61
  62 # include <bits/types.h>
  63
  64 /* Returned by `clock'.  */
  65 typedef __clock_t clock_t;
  66
  67 #endif /* clock_t not defined and <time.h> or need clock_t.  */
  68 #undef  __need_clock_t
  69
  70 #if !defined __time_t_defined && (defined _TIME_H || defined __need_time_t)
  71 # define __time_t_defined       1
  72
  73 # include <bits/types.h>
  74
  75 /* Returned by `time'.  */
  76 typedef __time_t time_t;
  77
  78 #endif /* time_t not defined and <time.h> or need time_t.  */
  79 #undef  __need_time_t
  80
  81
  82 #if !defined __timespec_defined && \
  83     ((defined _TIME_H && defined __USE_POSIX) || defined __need_timespec)
  84 # define __timespec_defined     1
  85
  86 /* POSIX.4 structure for a time value.  This is like a `struct timeval' but
  87    has nanoseconds instead of microseconds.  */
  88 struct timespec
  89   {
  90     long int tv_sec;            /* Seconds.  */
  91     long int tv_nsec;           /* Nanoseconds.  */
  92   };
  93
  94 #endif /* timespec not defined and <time.h> or need timespec.  */
  95 #undef  __need_timespec
  96
  97
  98 /* Value used for `tm_' field in `struct tmx' if describing the local
  99    time.  */
 100 #define _LOCALTIME              (0x7fffffff)
 101
 102 /* Value used for `tm_leapsecond' field if the number cannot be computed.  */
 103 #define _NO_LEAP_SECONDS        (0x7fffffff)
 104
 105
 106 #ifdef  _TIME_H
 107 /* Used by other time functions.  */
 108 struct tm
 109 {
 110   int tm_sec;                   /* Seconds.     [0-60] (1 leap second) */
 111   int tm_min;                   /* Minutes.     [0-59] */
 112   int tm_hour;                  /* Hours.       [0-23] */
 113   int tm_mday;                  /* Day.         [1-31] */
 114   int tm_mon;                   /* Month.       [0-11] */
 115   int tm_year;                  /* Year - 1900.  */
 116   int tm_wday;                  /* Day of week. [0-6] */
 117   int tm_yday;                  /* Days in year.[0-365] */
 118   int tm_isdst;                 /* DST.         [-1/0/1]*/
 119
 120 # ifdef __USE_BSD
 121   long int tm_gmtoff;           /* Seconds east of UTC.  */
 122   __const char *tm_zone;        /* Timezone abbreviation.  */
 123 # else
 124   long int __tm_gmtoff;         /* Seconds east of UTC.  */
 125   __const char *__tm_zone;      /* Timezone abbreviation.  */
 126 # endif
 127 };
 128
 129 #ifdef __USE_ISOC9X
 130 /* Extended form of `struct tm' defined in ISO C 9X.  */
 131 struct tmx
 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 # else
 146   long int __tm_gmtoff;         /* Seconds east of UTC.  */
 147 # endif
 148   __const char *__tm_zonestr;   /* Timezone abbreviation.  */
 149
 150   int tm_version;               /* Version number.  */
 151   int tm_zone;                  /* Minutes offset from UTC [-1439-1439] */
 152   int tm_leapsecs;              /* Number of leap seconds applied.  */
 153   void *tm_ext;                 /* Extension block.  */
 154   size_t tm_extlen;             /* Size of the extension block.  */
 155 };
 156 #endif
 157
 158
 159 /* Time used by the program so far (user time + system time).
 160    The result / CLOCKS_PER_SECOND is program time in seconds.  */
 161 extern clock_t clock __P ((void));
 162
 163 /* Return the current time and put it in *TIMER if TIMER is not NULL.  */
 164 extern time_t time __P ((time_t *__timer));
 165
 166 /* Return the difference between TIME1 and TIME0.  */
 167 extern double difftime __P ((time_t __time1, time_t __time0))
 168      __attribute__ ((__const__));
 169
 170 /* Return the `time_t' representation of TP and normalize TP.  */
 171 extern time_t mktime __P ((struct tm *__tp));
 172
 173 #ifdef __USE_ISOC9X
 174 /* Return the `time_t' representation of TP and normalize TP, taking
 175    account for the extra members in `struct tmx'.  */
 176 extern time_t mkxtime __P ((struct tmx *__tp));
 177 #endif
 178
 179
 180 /* Format TP into S according to FORMAT.
 181    Write no more than MAXSIZE characters and return the number
 182    of characters written, or 0 if it would exceed MAXSIZE.  */
 183 extern size_t strftime __P ((char *__restrict __s, size_t __maxsize,
 184                              __const char *__restrict __format,
 185                              __const struct tm *__restrict __tp));
 186
 187 #ifdef __USE_ISOC9X
 188 /* Format TP into S according to FORMAT.
 189    Write no more than MAXSIZE characters and return the number
 190    of characters written, or 0 if it would exceed MAXSIZE.  */
 191 extern size_t strfxtime __P ((char *__restrict __s, size_t __maxsize,
 192                               __const char *__restrict __format,
 193                               __const struct tmx *__restrict __tp));
 194
 195
 196 #endif
 197
 198 # ifdef __USE_XOPEN
 199 /* Parse S according to FORMAT and store binary time information in TP.
 200    The return value is a pointer to the first unparsed character in S.  */
 201 extern char *strptime __P ((__const char *__s, __const char *__fmt,
 202                             struct tm *__tp));
 203 # endif
 204
 205
 206 /* Return the `struct tm' representation of *TIMER
 207    in Universal Coordinated Time (aka Greenwich Mean Time).  */
 208 extern struct tm *gmtime __P ((__const time_t *__timer));
 209
 210 /* Return the `struct tm' representation
 211    of *TIMER in the local timezone.  */
 212 extern struct tm *localtime __P ((__const time_t *__timer));
 213
 214 # if defined __USE_POSIX || defined __USE_MISC
 215 /* Return the `struct tm' representation of *TIMER in UTC,
 216    using *TP to store the result.  */
 217 extern struct tm *__gmtime_r __P ((__const time_t *__timer,
 218                                    struct tm *__tp));
 219 extern struct tm *gmtime_r __P ((__const time_t *__timer,
 220                                  struct tm *__tp));
 221
 222 /* Return the `struct tm' representation of *TIMER in local time,
 223    using *TP to store the result.  */
 224 extern struct tm *localtime_r __P ((__const time_t *__timer,
 225                                     struct tm *__tp));
 226 # endif /* POSIX or misc */
 227
 228 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 229    that is the representation of TP in this format.  */
 230 extern char *asctime __P ((__const struct tm *__tp));
 231
 232 /* Equivalent to `asctime (localtime (timer))'.  */
 233 extern char *ctime __P ((__const time_t *__timer));
 234
 235 # if defined __USE_POSIX || defined __USE_MISC
 236 /* Reentrant versions of the above functions.  */
 237
 238 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
 239    that is the representation of TP in this format.  */
 240 extern char *asctime_r __P ((__const struct tm *__tp, char *__buf));
 241
 242 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'.  */
 243 extern char *ctime_r __P ((__const time_t *__timer, char *__buf));
 244 # endif /* POSIX or misc */
 245
 246
 247 /* Defined in localtime.c.  */
 248 extern char *__tzname[2];       /* Current timezone names.  */
 249 extern int __daylight;          /* If daylight-saving time is ever in use.  */
 250 extern long int __timezone;     /* Seconds west of UTC.  */
 251
 252
 253 # ifdef __USE_POSIX
 254 /* Same as above.  */
 255 extern char *tzname[2];
 256
 257 /* Set time conversion information from the TZ environment variable.
 258    If TZ is not defined, a locale-dependent default is used.  */
 259 extern void tzset __P ((void));
 260 # endif
 261
 262 # if defined __USE_SVID || defined __USE_XOPEN
 263 extern int daylight;
 264 extern long int timezone;
 265 # endif
 266
 267 # ifdef __USE_SVID
 268 /* Set the system time to *WHEN.
 269    This call is restricted to the superuser.  */
 270 extern int stime __P ((__const time_t *__when));
 271 # endif
 272
 273
 274 /* Nonzero if YEAR is a leap year (every 4 years,
 275    except every 100th isn't, and every 400th is).  */
 276 # define __isleap(year) \
 277   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 278
 279
 280 # ifdef __USE_MISC
 281 /* Miscellaneous functions many Unices inherited from the public domain
 282    localtime package.  These are included only for compatibility.  */
 283
 284 /* Like `mktime', but for TP represents Universal Time, not local time.  */
 285 extern time_t timegm __P ((struct tm *__tp));
 286
 287 /* Another name for `mktime'.  */
 288 extern time_t timelocal __P ((struct tm *__tp));
 289
 290 /* Return the number of days in YEAR.  */
 291 extern int dysize __P ((int __year));
 292 # endif
 293
 294
 295 # ifdef __USE_POSIX199309
 296 /* Pause execution for a number of nanoseconds.  */
 297 extern int nanosleep __P ((__const struct timespec *__requested_time,
 298                            struct timespec *__remaining));
 299 # endif
 300
 301
 302 # ifdef __USE_XOPEN_EXTENDED
 303 /* Set to one of the following values to indicate an error.
 304      1  the DATEMSK environment variable is null or undefined,
 305      2  the template file cannot be opened for reading,
 306      3  failed to get file status information,
 307      4  the template file is not a regular file,
 308      5  an error is encountered while reading the template file,
 309      6  memory allication failed (not enough memory available),
 310      7  there is no line in the template that matches the input,
 311      8  invalid input specification Example: February 31 or a time is
 312         specified that can not be represented in a time_t (representing
 313         the time in seconds since 00:00:00 UTC, January 1, 1970) */
 314 extern int getdate_err;
 315
 316 /* Parse the given string as a date specification and return a value
 317    representing the value.  The templates from the file identified by
 318    the environment variable DATEMSK are used.  In case of an error
 319    `getdate_err' is set.  */
 320 extern struct tm *getdate __P ((__const char *__string));
 321 # endif
 322
 323 # ifdef __USE_GNU
 324 /* Since `getdate' is not reentrant because of the use of `getdate_err'
 325    and the static buffer to return the result in, we provide a thread-safe
 326    variant.  The functionality is the same.  The result is returned in
 327    the buffer pointed to by RESBUFP and in case of an error the return
 328    value is != 0 with the same values as given above for `getdate_err'.  */
 329 extern int getdate_r __P ((__const char *__string, struct tm *__resbufp));
 330 # endif
 331
 332
 333 __END_DECLS
 334
 335 #endif /* <time.h> included.  */
 336
 337 #endif /* <time.h> not already included.  */