TLA Line data Source code
1 : /* Convert a broken-down timestamp to a string. */
2 :
3 : /*
4 : * Copyright 1989 The Regents of the University of California.
5 : * All rights reserved.
6 : *
7 : * Redistribution and use in source and binary forms, with or without
8 : * modification, are permitted provided that the following conditions
9 : * are met:
10 : * 1. Redistributions of source code must retain the above copyright
11 : * notice, this list of conditions and the following disclaimer.
12 : * 2. Redistributions in binary form must reproduce the above copyright
13 : * notice, this list of conditions and the following disclaimer in the
14 : * documentation and/or other materials provided with the distribution.
15 : * 3. Neither the name of the University nor the names of its contributors
16 : * may be used to endorse or promote products derived from this software
17 : * without specific prior written permission.
18 : *
19 : * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
20 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 : * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 : * SUCH DAMAGE.
30 : */
31 :
32 : /*
33 : * Based on the UCB version with the copyright notice appearing above.
34 : *
35 : * This is ANSIish only when "multibyte character == plain character".
36 : *
37 : * IDENTIFICATION
38 : * src/timezone/strftime.c
39 : */
40 :
41 : #include "postgres.h"
42 :
43 : #include <fcntl.h>
44 :
45 : #include "private.h"
46 :
47 :
48 : struct lc_time_T
49 : {
50 : const char *mon[MONSPERYEAR];
51 : const char *month[MONSPERYEAR];
52 : const char *wday[DAYSPERWEEK];
53 : const char *weekday[DAYSPERWEEK];
54 : const char *X_fmt;
55 : const char *x_fmt;
56 : const char *c_fmt;
57 : const char *am;
58 : const char *pm;
59 : const char *date_fmt;
60 : };
61 :
62 : #define Locale (&C_time_locale)
63 :
64 : static const struct lc_time_T C_time_locale = {
65 : {
66 : "Jan", "Feb", "Mar", "Apr", "May", "Jun",
67 : "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
68 : }, {
69 : "January", "February", "March", "April", "May", "June",
70 : "July", "August", "September", "October", "November", "December"
71 : }, {
72 : "Sun", "Mon", "Tue", "Wed",
73 : "Thu", "Fri", "Sat"
74 : }, {
75 : "Sunday", "Monday", "Tuesday", "Wednesday",
76 : "Thursday", "Friday", "Saturday"
77 : },
78 :
79 : /* X_fmt */
80 : "%H:%M:%S",
81 :
82 : /*
83 : * x_fmt
84 : *
85 : * C99 and later require this format. Using just numbers (as here) makes
86 : * Quakers happier; it's also compatible with SVR4.
87 : */
88 : "%m/%d/%y",
89 :
90 : /*
91 : * c_fmt
92 : *
93 : * C99 and later require this format. Previously this code used "%D %X",
94 : * but we now conform to C99. Note that "%a %b %d %H:%M:%S %Y" is used by
95 : * Solaris 2.3.
96 : */
97 : "%a %b %e %T %Y",
98 :
99 : /* am */
100 : "AM",
101 :
102 : /* pm */
103 : "PM",
104 :
105 : /* date_fmt */
106 : "%a %b %e %H:%M:%S %Z %Y"
107 : };
108 :
109 : enum warn
110 : {
111 : IN_NONE, IN_SOME, IN_THIS, IN_ALL
112 : };
113 :
114 : static char *_add(const char *str, char *pt, const char *ptlim);
115 : static char *_conv(int n, const char *format, char *pt, const char *ptlim);
116 : static char *_fmt(const char *format, const struct pg_tm *t, char *pt, const char *ptlim,
117 : enum warn *warnp);
118 : static char *_yconv(int a, int b, bool convert_top, bool convert_yy, char *pt, char const *ptlim);
119 :
120 :
121 : /*
122 : * Convert timestamp t to string s, a caller-allocated buffer of size maxsize,
123 : * using the given format pattern.
124 : *
125 : * See also timestamptz_to_str.
126 : */
127 : size_t
128 CBC 350781 : pg_strftime(char *s, size_t maxsize, const char *format, const struct pg_tm *t)
129 : {
130 : char *p;
131 350781 : int saved_errno = errno;
132 350781 : enum warn warn = IN_NONE;
133 :
134 350781 : p = _fmt(format, t, s, s + maxsize, &warn);
135 350781 : if (!p)
136 : {
137 UBC 0 : errno = EOVERFLOW;
138 0 : return 0;
139 : }
140 CBC 350781 : if (p == s + maxsize)
141 : {
142 UBC 0 : errno = ERANGE;
143 0 : return 0;
144 : }
145 CBC 350781 : *p = '\0';
146 350781 : errno = saved_errno;
147 350781 : return p - s;
148 : }
149 :
150 : static char *
151 350781 : _fmt(const char *format, const struct pg_tm *t, char *pt,
152 : const char *ptlim, enum warn *warnp)
153 : {
154 5837249 : for (; *format; ++format)
155 : {
156 5486468 : if (*format == '%')
157 : {
158 2456258 : label:
159 2456258 : switch (*++format)
160 : {
161 UBC 0 : case '\0':
162 0 : --format;
163 0 : break;
164 0 : case 'A':
165 0 : pt = _add((t->tm_wday < 0 ||
166 0 : t->tm_wday >= DAYSPERWEEK) ?
167 0 : "?" : Locale->weekday[t->tm_wday],
168 : pt, ptlim);
169 0 : continue;
170 CBC 400 : case 'a':
171 800 : pt = _add((t->tm_wday < 0 ||
172 400 : t->tm_wday >= DAYSPERWEEK) ?
173 400 : "?" : Locale->wday[t->tm_wday],
174 : pt, ptlim);
175 400 : continue;
176 UBC 0 : case 'B':
177 0 : pt = _add((t->tm_mon < 0 ||
178 0 : t->tm_mon >= MONSPERYEAR) ?
179 0 : "?" : Locale->month[t->tm_mon],
180 : pt, ptlim);
181 0 : continue;
182 CBC 400 : case 'b':
183 : case 'h':
184 800 : pt = _add((t->tm_mon < 0 ||
185 400 : t->tm_mon >= MONSPERYEAR) ?
186 400 : "?" : Locale->mon[t->tm_mon],
187 : pt, ptlim);
188 400 : continue;
189 UBC 0 : case 'C':
190 :
191 : /*
192 : * %C used to do a... _fmt("%a %b %e %X %Y", t);
193 : * ...whereas now POSIX 1003.2 calls for something
194 : * completely different. (ado, 1993-05-24)
195 : */
196 0 : pt = _yconv(t->tm_year, TM_YEAR_BASE,
197 : true, false, pt, ptlim);
198 0 : continue;
199 0 : case 'c':
200 : {
201 0 : enum warn warn2 = IN_SOME;
202 :
203 0 : pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
204 0 : if (warn2 == IN_ALL)
205 0 : warn2 = IN_THIS;
206 0 : if (warn2 > *warnp)
207 0 : *warnp = warn2;
208 : }
209 0 : continue;
210 0 : case 'D':
211 0 : pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
212 0 : continue;
213 CBC 350781 : case 'd':
214 350781 : pt = _conv(t->tm_mday, "%02d", pt, ptlim);
215 350781 : continue;
216 UBC 0 : case 'E':
217 : case 'O':
218 :
219 : /*
220 : * Locale modifiers of C99 and later. The sequences %Ec
221 : * %EC %Ex %EX %Ey %EY %Od %oe %OH %OI %Om %OM %OS %Ou %OU
222 : * %OV %Ow %OW %Oy are supposed to provide alternative
223 : * representations.
224 : */
225 0 : goto label;
226 0 : case 'e':
227 0 : pt = _conv(t->tm_mday, "%2d", pt, ptlim);
228 0 : continue;
229 0 : case 'F':
230 0 : pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
231 0 : continue;
232 CBC 350781 : case 'H':
233 350781 : pt = _conv(t->tm_hour, "%02d", pt, ptlim);
234 350781 : continue;
235 UBC 0 : case 'I':
236 0 : pt = _conv((t->tm_hour % 12) ?
237 0 : (t->tm_hour % 12) : 12,
238 : "%02d", pt, ptlim);
239 0 : continue;
240 0 : case 'j':
241 0 : pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
242 0 : continue;
243 0 : case 'k':
244 :
245 : /*
246 : * This used to be... _conv(t->tm_hour % 12 ? t->tm_hour %
247 : * 12 : 12, 2, ' '); ...and has been changed to the below
248 : * to match SunOS 4.1.1 and Arnold Robbins' strftime
249 : * version 3.0. That is, "%k" and "%l" have been swapped.
250 : * (ado, 1993-05-24)
251 : */
252 0 : pt = _conv(t->tm_hour, "%2d", pt, ptlim);
253 0 : continue;
254 : #ifdef KITCHEN_SINK
255 : case 'K':
256 :
257 : /*
258 : * After all this time, still unclaimed!
259 : */
260 : pt = _add("kitchen sink", pt, ptlim);
261 : continue;
262 : #endif /* defined KITCHEN_SINK */
263 0 : case 'l':
264 :
265 : /*
266 : * This used to be... _conv(t->tm_hour, 2, ' '); ...and
267 : * has been changed to the below to match SunOS 4.1.1 and
268 : * Arnold Robbin's strftime version 3.0. That is, "%k" and
269 : * "%l" have been swapped. (ado, 1993-05-24)
270 : */
271 0 : pt = _conv((t->tm_hour % 12) ?
272 0 : (t->tm_hour % 12) : 12,
273 : "%2d", pt, ptlim);
274 0 : continue;
275 CBC 350781 : case 'M':
276 350781 : pt = _conv(t->tm_min, "%02d", pt, ptlim);
277 350781 : continue;
278 350381 : case 'm':
279 350381 : pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
280 350381 : continue;
281 UBC 0 : case 'n':
282 0 : pt = _add("\n", pt, ptlim);
283 0 : continue;
284 0 : case 'p':
285 0 : pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
286 : Locale->pm :
287 : Locale->am,
288 : pt, ptlim);
289 0 : continue;
290 0 : case 'R':
291 0 : pt = _fmt("%H:%M", t, pt, ptlim, warnp);
292 0 : continue;
293 0 : case 'r':
294 0 : pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp);
295 0 : continue;
296 CBC 350781 : case 'S':
297 350781 : pt = _conv(t->tm_sec, "%02d", pt, ptlim);
298 350781 : continue;
299 UBC 0 : case 'T':
300 0 : pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
301 0 : continue;
302 0 : case 't':
303 0 : pt = _add("\t", pt, ptlim);
304 0 : continue;
305 0 : case 'U':
306 0 : pt = _conv((t->tm_yday + DAYSPERWEEK -
307 0 : t->tm_wday) / DAYSPERWEEK,
308 : "%02d", pt, ptlim);
309 0 : continue;
310 0 : case 'u':
311 :
312 : /*
313 : * From Arnold Robbins' strftime version 3.0: "ISO 8601:
314 : * Weekday as a decimal number [1 (Monday) - 7]" (ado,
315 : * 1993-05-24)
316 : */
317 0 : pt = _conv((t->tm_wday == 0) ?
318 : DAYSPERWEEK : t->tm_wday,
319 : "%d", pt, ptlim);
320 0 : continue;
321 0 : case 'V': /* ISO 8601 week number */
322 : case 'G': /* ISO 8601 year (four digits) */
323 : case 'g': /* ISO 8601 year (two digits) */
324 : /*
325 : * From Arnold Robbins' strftime version 3.0: "the week number of the
326 : * year (the first Monday as the first day of week 1) as a decimal number
327 : * (01-53)."
328 : * (ado, 1993-05-24)
329 : *
330 : * From <https://www.cl.cam.ac.uk/~mgk25/iso-time.html> by Markus Kuhn:
331 : * "Week 01 of a year is per definition the first week which has the
332 : * Thursday in this year, which is equivalent to the week which contains
333 : * the fourth day of January. In other words, the first week of a new year
334 : * is the week which has the majority of its days in the new year. Week 01
335 : * might also contain days from the previous year and the week before week
336 : * 01 of a year is the last week (52 or 53) of the previous year even if
337 : * it contains days from the new year. A week starts with Monday (day 1)
338 : * and ends with Sunday (day 7). For example, the first week of the year
339 : * 1997 lasts from 1996-12-30 to 1997-01-05..."
340 : * (ado, 1996-01-02)
341 : */
342 : {
343 : int year;
344 : int base;
345 : int yday;
346 : int wday;
347 : int w;
348 :
349 0 : year = t->tm_year;
350 0 : base = TM_YEAR_BASE;
351 0 : yday = t->tm_yday;
352 0 : wday = t->tm_wday;
353 : for (;;)
354 0 : {
355 : int len;
356 : int bot;
357 : int top;
358 :
359 0 : len = isleap_sum(year, base) ?
360 0 : DAYSPERLYEAR :
361 : DAYSPERNYEAR;
362 :
363 : /*
364 : * What yday (-3 ... 3) does the ISO year begin
365 : * on?
366 : */
367 0 : bot = ((yday + 11 - wday) %
368 : DAYSPERWEEK) - 3;
369 :
370 : /*
371 : * What yday does the NEXT ISO year begin on?
372 : */
373 0 : top = bot -
374 0 : (len % DAYSPERWEEK);
375 0 : if (top < -3)
376 0 : top += DAYSPERWEEK;
377 0 : top += len;
378 0 : if (yday >= top)
379 : {
380 0 : ++base;
381 0 : w = 1;
382 0 : break;
383 : }
384 0 : if (yday >= bot)
385 : {
386 0 : w = 1 + ((yday - bot) /
387 : DAYSPERWEEK);
388 0 : break;
389 : }
390 0 : --base;
391 0 : yday += isleap_sum(year, base) ?
392 0 : DAYSPERLYEAR :
393 : DAYSPERNYEAR;
394 : }
395 0 : if (*format == 'V')
396 0 : pt = _conv(w, "%02d",
397 : pt, ptlim);
398 0 : else if (*format == 'g')
399 : {
400 0 : *warnp = IN_ALL;
401 0 : pt = _yconv(year, base,
402 : false, true,
403 : pt, ptlim);
404 : }
405 : else
406 0 : pt = _yconv(year, base,
407 : true, true,
408 : pt, ptlim);
409 : }
410 0 : continue;
411 0 : case 'v':
412 :
413 : /*
414 : * From Arnold Robbins' strftime version 3.0: "date as
415 : * dd-bbb-YYYY" (ado, 1993-05-24)
416 : */
417 0 : pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
418 0 : continue;
419 0 : case 'W':
420 0 : pt = _conv((t->tm_yday + DAYSPERWEEK -
421 0 : (t->tm_wday ?
422 0 : (t->tm_wday - 1) :
423 : (DAYSPERWEEK - 1))) / DAYSPERWEEK,
424 : "%02d", pt, ptlim);
425 0 : continue;
426 0 : case 'w':
427 0 : pt = _conv(t->tm_wday, "%d", pt, ptlim);
428 0 : continue;
429 0 : case 'X':
430 0 : pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
431 0 : continue;
432 0 : case 'x':
433 : {
434 0 : enum warn warn2 = IN_SOME;
435 :
436 0 : pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
437 0 : if (warn2 == IN_ALL)
438 0 : warn2 = IN_THIS;
439 0 : if (warn2 > *warnp)
440 0 : *warnp = warn2;
441 : }
442 0 : continue;
443 0 : case 'y':
444 0 : *warnp = IN_ALL;
445 0 : pt = _yconv(t->tm_year, TM_YEAR_BASE,
446 : false, true,
447 : pt, ptlim);
448 0 : continue;
449 CBC 350781 : case 'Y':
450 350781 : pt = _yconv(t->tm_year, TM_YEAR_BASE,
451 : true, true,
452 : pt, ptlim);
453 350781 : continue;
454 350772 : case 'Z':
455 350772 : if (t->tm_zone != NULL)
456 350772 : pt = _add(t->tm_zone, pt, ptlim);
457 :
458 : /*
459 : * C99 and later say that %Z must be replaced by the empty
460 : * string if the time zone abbreviation is not
461 : * determinable.
462 : */
463 350772 : continue;
464 UBC 0 : case 'z':
465 : {
466 : long diff;
467 : char const *sign;
468 : bool negative;
469 :
470 0 : if (t->tm_isdst < 0)
471 0 : continue;
472 0 : diff = t->tm_gmtoff;
473 0 : negative = diff < 0;
474 0 : if (diff == 0)
475 : {
476 0 : if (t->tm_zone != NULL)
477 0 : negative = t->tm_zone[0] == '-';
478 : }
479 0 : if (negative)
480 : {
481 0 : sign = "-";
482 0 : diff = -diff;
483 : }
484 : else
485 0 : sign = "+";
486 0 : pt = _add(sign, pt, ptlim);
487 0 : diff /= SECSPERMIN;
488 0 : diff = (diff / MINSPERHOUR) * 100 +
489 0 : (diff % MINSPERHOUR);
490 0 : pt = _conv(diff, "%04d", pt, ptlim);
491 : }
492 0 : continue;
493 0 : case '+':
494 0 : pt = _fmt(Locale->date_fmt, t, pt, ptlim,
495 : warnp);
496 0 : continue;
497 CBC 400 : case '%':
498 :
499 : /*
500 : * X311J/88-090 (4.12.3.5): if conversion char is
501 : * undefined, behavior is undefined. Print out the
502 : * character itself as printf(3) also does.
503 : */
504 : default:
505 400 : break;
506 : }
507 : }
508 3030610 : if (pt == ptlim)
509 UBC 0 : break;
510 CBC 3030610 : *pt++ = *format;
511 : }
512 350781 : return pt;
513 : }
514 :
515 : static char *
516 2455067 : _conv(int n, const char *format, char *pt, const char *ptlim)
517 : {
518 : char buf[INT_STRLEN_MAXIMUM(int) + 1];
519 :
520 2455067 : sprintf(buf, format, n);
521 2455067 : return _add(buf, pt, ptlim);
522 : }
523 :
524 : static char *
525 2806639 : _add(const char *str, char *pt, const char *ptlim)
526 : {
527 8771489 : while (pt < ptlim && (*pt = *str++) != '\0')
528 5964850 : ++pt;
529 2806639 : return pt;
530 : }
531 :
532 : /*
533 : * POSIX and the C Standard are unclear or inconsistent about
534 : * what %C and %y do if the year is negative or exceeds 9999.
535 : * Use the convention that %C concatenated with %y yields the
536 : * same output as %Y, and that %Y contains at least 4 bytes,
537 : * with more only if necessary.
538 : */
539 :
540 : static char *
541 350781 : _yconv(int a, int b, bool convert_top, bool convert_yy,
542 : char *pt, const char *ptlim)
543 : {
544 : int lead;
545 : int trail;
546 :
547 : #define DIVISOR 100
548 350781 : trail = a % DIVISOR + b % DIVISOR;
549 350781 : lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
550 350781 : trail %= DIVISOR;
551 350781 : if (trail < 0 && lead > 0)
552 : {
553 UBC 0 : trail += DIVISOR;
554 0 : --lead;
555 : }
556 CBC 350781 : else if (lead < 0 && trail > 0)
557 : {
558 UBC 0 : trail -= DIVISOR;
559 0 : ++lead;
560 : }
561 CBC 350781 : if (convert_top)
562 : {
563 350781 : if (lead == 0 && trail < 0)
564 UBC 0 : pt = _add("-0", pt, ptlim);
565 : else
566 CBC 350781 : pt = _conv(lead, "%02d", pt, ptlim);
567 : }
568 350781 : if (convert_yy)
569 350781 : pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
570 350781 : return pt;
571 : }
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