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