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 : * Unlike standard strftime(), we guarantee to provide a null-terminated
126 : * result even on failure, so long as maxsize > 0. If we overrun the buffer,
127 : * return an empty string rather than risking mis-encoded multibyte output.
128 : * (Since this module only supports C locale, you might think multibyte
129 : * characters are impossible --- but the time zone name printed by %Z comes
130 : * from outside and could contain such.)
131 : *
132 : * See also timestamptz_to_str.
133 : */
134 : size_t
135 1438373 : pg_strftime(char *s, size_t maxsize, const char *format, const struct pg_tm *t)
136 : {
137 : char *p;
138 1438373 : int saved_errno = errno;
139 1438373 : enum warn warn = IN_NONE;
140 :
141 1438373 : p = _fmt(format, t, s, s + maxsize, &warn);
142 1438373 : if (!p)
143 : {
144 0 : errno = EOVERFLOW;
145 0 : if (maxsize > 0)
146 0 : *s = '\0';
147 0 : return 0;
148 : }
149 1438373 : if (p == s + maxsize)
150 : {
151 0 : errno = ERANGE;
152 0 : if (maxsize > 0)
153 0 : *s = '\0';
154 0 : return 0;
155 : }
156 1438373 : *p = '\0';
157 1438373 : errno = saved_errno;
158 1438373 : return p - s;
159 : }
160 :
161 : static char *
162 1438373 : _fmt(const char *format, const struct pg_tm *t, char *pt,
163 : const char *ptlim, enum warn *warnp)
164 : {
165 25135713 : for (; *format; ++format)
166 : {
167 23697340 : if (*format == '%')
168 : {
169 10063802 : label:
170 10063802 : switch (*++format)
171 : {
172 0 : case '\0':
173 0 : --format;
174 0 : break;
175 0 : case 'A':
176 0 : pt = _add((t->tm_wday < 0 ||
177 0 : t->tm_wday >= DAYSPERWEEK) ?
178 0 : "?" : Locale->weekday[t->tm_wday],
179 : pt, ptlim);
180 0 : continue;
181 800 : case 'a':
182 1600 : pt = _add((t->tm_wday < 0 ||
183 800 : t->tm_wday >= DAYSPERWEEK) ?
184 800 : "?" : Locale->wday[t->tm_wday],
185 : pt, ptlim);
186 800 : continue;
187 0 : case 'B':
188 0 : pt = _add((t->tm_mon < 0 ||
189 0 : t->tm_mon >= MONSPERYEAR) ?
190 0 : "?" : Locale->month[t->tm_mon],
191 : pt, ptlim);
192 0 : continue;
193 800 : case 'b':
194 : case 'h':
195 1600 : pt = _add((t->tm_mon < 0 ||
196 800 : t->tm_mon >= MONSPERYEAR) ?
197 800 : "?" : Locale->mon[t->tm_mon],
198 : pt, ptlim);
199 800 : continue;
200 0 : case 'C':
201 :
202 : /*
203 : * %C used to do a... _fmt("%a %b %e %X %Y", t);
204 : * ...whereas now POSIX 1003.2 calls for something
205 : * completely different. (ado, 1993-05-24)
206 : */
207 0 : pt = _yconv(t->tm_year, TM_YEAR_BASE,
208 : true, false, pt, ptlim);
209 0 : continue;
210 0 : case 'c':
211 : {
212 0 : enum warn warn2 = IN_SOME;
213 :
214 0 : pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
215 0 : if (warn2 == IN_ALL)
216 0 : warn2 = IN_THIS;
217 0 : if (warn2 > *warnp)
218 0 : *warnp = warn2;
219 : }
220 0 : continue;
221 0 : case 'D':
222 0 : pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
223 0 : continue;
224 1437573 : case 'd':
225 1437573 : pt = _conv(t->tm_mday, "%02d", pt, ptlim);
226 1437573 : continue;
227 0 : case 'E':
228 : case 'O':
229 :
230 : /*
231 : * Locale modifiers of C99 and later. The sequences %Ec
232 : * %EC %Ex %EX %Ey %EY %Od %oe %OH %OI %Om %OM %OS %Ou %OU
233 : * %OV %Ow %OW %Oy are supposed to provide alternative
234 : * representations.
235 : */
236 0 : goto label;
237 0 : case 'e':
238 0 : pt = _conv(t->tm_mday, "%2d", pt, ptlim);
239 0 : continue;
240 0 : case 'F':
241 0 : pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
242 0 : continue;
243 1437573 : case 'H':
244 1437573 : pt = _conv(t->tm_hour, "%02d", pt, ptlim);
245 1437573 : continue;
246 0 : case 'I':
247 0 : pt = _conv((t->tm_hour % 12) ?
248 0 : (t->tm_hour % 12) : 12,
249 : "%02d", pt, ptlim);
250 0 : continue;
251 0 : case 'j':
252 0 : pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
253 0 : continue;
254 0 : case 'k':
255 :
256 : /*
257 : * This used to be... _conv(t->tm_hour % 12 ? t->tm_hour %
258 : * 12 : 12, 2, ' '); ...and has been changed to the below
259 : * to match SunOS 4.1.1 and Arnold Robbins' strftime
260 : * version 3.0. That is, "%k" and "%l" have been swapped.
261 : * (ado, 1993-05-24)
262 : */
263 0 : pt = _conv(t->tm_hour, "%2d", pt, ptlim);
264 0 : continue;
265 : #ifdef KITCHEN_SINK
266 : case 'K':
267 :
268 : /*
269 : * After all this time, still unclaimed!
270 : */
271 : pt = _add("kitchen sink", pt, ptlim);
272 : continue;
273 : #endif /* defined KITCHEN_SINK */
274 0 : case 'l':
275 :
276 : /*
277 : * This used to be... _conv(t->tm_hour, 2, ' '); ...and
278 : * has been changed to the below to match SunOS 4.1.1 and
279 : * Arnold Robbin's strftime version 3.0. That is, "%k" and
280 : * "%l" have been swapped. (ado, 1993-05-24)
281 : */
282 0 : pt = _conv((t->tm_hour % 12) ?
283 0 : (t->tm_hour % 12) : 12,
284 : "%2d", pt, ptlim);
285 0 : continue;
286 1437573 : case 'M':
287 1437573 : pt = _conv(t->tm_min, "%02d", pt, ptlim);
288 1437573 : continue;
289 1436773 : case 'm':
290 1436773 : pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
291 1436773 : continue;
292 0 : case 'n':
293 0 : pt = _add("\n", pt, ptlim);
294 0 : continue;
295 0 : case 'p':
296 0 : pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
297 : Locale->pm :
298 : Locale->am,
299 : pt, ptlim);
300 0 : continue;
301 0 : case 'R':
302 0 : pt = _fmt("%H:%M", t, pt, ptlim, warnp);
303 0 : continue;
304 0 : case 'r':
305 0 : pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp);
306 0 : continue;
307 1437573 : case 'S':
308 1437573 : pt = _conv(t->tm_sec, "%02d", pt, ptlim);
309 1437573 : continue;
310 0 : case 'T':
311 0 : pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
312 0 : continue;
313 0 : case 't':
314 0 : pt = _add("\t", pt, ptlim);
315 0 : continue;
316 0 : case 'U':
317 0 : pt = _conv((t->tm_yday + DAYSPERWEEK -
318 0 : t->tm_wday) / DAYSPERWEEK,
319 : "%02d", pt, ptlim);
320 0 : continue;
321 0 : case 'u':
322 :
323 : /*
324 : * From Arnold Robbins' strftime version 3.0: "ISO 8601:
325 : * Weekday as a decimal number [1 (Monday) - 7]" (ado,
326 : * 1993-05-24)
327 : */
328 0 : pt = _conv((t->tm_wday == 0) ?
329 : DAYSPERWEEK : t->tm_wday,
330 : "%d", pt, ptlim);
331 0 : continue;
332 0 : case 'V': /* ISO 8601 week number */
333 : case 'G': /* ISO 8601 year (four digits) */
334 : case 'g': /* ISO 8601 year (two digits) */
335 : /*
336 : * From Arnold Robbins' strftime version 3.0: "the week number of the
337 : * year (the first Monday as the first day of week 1) as a decimal number
338 : * (01-53)."
339 : * (ado, 1993-05-24)
340 : *
341 : * From <https://www.cl.cam.ac.uk/~mgk25/iso-time.html> by Markus Kuhn:
342 : * "Week 01 of a year is per definition the first week which has the
343 : * Thursday in this year, which is equivalent to the week which contains
344 : * the fourth day of January. In other words, the first week of a new year
345 : * is the week which has the majority of its days in the new year. Week 01
346 : * might also contain days from the previous year and the week before week
347 : * 01 of a year is the last week (52 or 53) of the previous year even if
348 : * it contains days from the new year. A week starts with Monday (day 1)
349 : * and ends with Sunday (day 7). For example, the first week of the year
350 : * 1997 lasts from 1996-12-30 to 1997-01-05..."
351 : * (ado, 1996-01-02)
352 : */
353 : {
354 : int year;
355 : int base;
356 : int yday;
357 : int wday;
358 : int w;
359 :
360 0 : year = t->tm_year;
361 0 : base = TM_YEAR_BASE;
362 0 : yday = t->tm_yday;
363 0 : wday = t->tm_wday;
364 : for (;;)
365 0 : {
366 : int len;
367 : int bot;
368 : int top;
369 :
370 0 : len = isleap_sum(year, base) ?
371 0 : DAYSPERLYEAR :
372 : DAYSPERNYEAR;
373 :
374 : /*
375 : * What yday (-3 ... 3) does the ISO year begin
376 : * on?
377 : */
378 0 : bot = ((yday + 11 - wday) %
379 : DAYSPERWEEK) - 3;
380 :
381 : /*
382 : * What yday does the NEXT ISO year begin on?
383 : */
384 0 : top = bot -
385 0 : (len % DAYSPERWEEK);
386 0 : if (top < -3)
387 0 : top += DAYSPERWEEK;
388 0 : top += len;
389 0 : if (yday >= top)
390 : {
391 0 : ++base;
392 0 : w = 1;
393 0 : break;
394 : }
395 0 : if (yday >= bot)
396 : {
397 0 : w = 1 + ((yday - bot) /
398 : DAYSPERWEEK);
399 0 : break;
400 : }
401 0 : --base;
402 0 : yday += isleap_sum(year, base) ?
403 0 : DAYSPERLYEAR :
404 : DAYSPERNYEAR;
405 : }
406 0 : if (*format == 'V')
407 0 : pt = _conv(w, "%02d",
408 : pt, ptlim);
409 0 : else if (*format == 'g')
410 : {
411 0 : *warnp = IN_ALL;
412 0 : pt = _yconv(year, base,
413 : false, true,
414 : pt, ptlim);
415 : }
416 : else
417 0 : pt = _yconv(year, base,
418 : true, true,
419 : pt, ptlim);
420 : }
421 0 : continue;
422 0 : case 'v':
423 :
424 : /*
425 : * From Arnold Robbins' strftime version 3.0: "date as
426 : * dd-bbb-YYYY" (ado, 1993-05-24)
427 : */
428 0 : pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
429 0 : continue;
430 0 : case 'W':
431 0 : pt = _conv((t->tm_yday + DAYSPERWEEK -
432 0 : (t->tm_wday ?
433 0 : (t->tm_wday - 1) :
434 : (DAYSPERWEEK - 1))) / DAYSPERWEEK,
435 : "%02d", pt, ptlim);
436 0 : continue;
437 0 : case 'w':
438 0 : pt = _conv(t->tm_wday, "%d", pt, ptlim);
439 0 : continue;
440 0 : case 'X':
441 0 : pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
442 0 : continue;
443 0 : case 'x':
444 : {
445 0 : enum warn warn2 = IN_SOME;
446 :
447 0 : pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
448 0 : if (warn2 == IN_ALL)
449 0 : warn2 = IN_THIS;
450 0 : if (warn2 > *warnp)
451 0 : *warnp = warn2;
452 : }
453 0 : continue;
454 0 : case 'y':
455 0 : *warnp = IN_ALL;
456 0 : pt = _yconv(t->tm_year, TM_YEAR_BASE,
457 : false, true,
458 : pt, ptlim);
459 0 : continue;
460 1437573 : case 'Y':
461 1437573 : pt = _yconv(t->tm_year, TM_YEAR_BASE,
462 : true, true,
463 : pt, ptlim);
464 1437573 : continue;
465 1437564 : case 'Z':
466 1437564 : if (t->tm_zone != NULL)
467 1437564 : pt = _add(t->tm_zone, pt, ptlim);
468 :
469 : /*
470 : * C99 and later say that %Z must be replaced by the empty
471 : * string if the time zone abbreviation is not
472 : * determinable.
473 : */
474 1437564 : continue;
475 0 : case 'z':
476 : {
477 : long diff;
478 : char const *sign;
479 : bool negative;
480 :
481 0 : if (t->tm_isdst < 0)
482 0 : continue;
483 0 : diff = t->tm_gmtoff;
484 0 : negative = diff < 0;
485 0 : if (diff == 0)
486 : {
487 0 : if (t->tm_zone != NULL)
488 0 : negative = t->tm_zone[0] == '-';
489 : }
490 0 : if (negative)
491 : {
492 0 : sign = "-";
493 0 : diff = -diff;
494 : }
495 : else
496 0 : sign = "+";
497 0 : pt = _add(sign, pt, ptlim);
498 0 : diff /= SECSPERMIN;
499 0 : diff = (diff / MINSPERHOUR) * 100 +
500 0 : (diff % MINSPERHOUR);
501 0 : pt = _conv(diff, "%04d", pt, ptlim);
502 : }
503 0 : continue;
504 0 : case '+':
505 0 : pt = _fmt(Locale->date_fmt, t, pt, ptlim,
506 : warnp);
507 0 : continue;
508 0 : case '%':
509 :
510 : /*
511 : * X311J/88-090 (4.12.3.5): if conversion char is
512 : * undefined, behavior is undefined. Print out the
513 : * character itself as printf(3) also does.
514 : */
515 : default:
516 0 : break;
517 : }
518 : }
519 13633538 : if (pt == ptlim)
520 0 : break;
521 13633538 : *pt++ = *format;
522 : }
523 1438373 : return pt;
524 : }
525 :
526 : static char *
527 10062211 : _conv(int n, const char *format, char *pt, const char *ptlim)
528 : {
529 : char buf[INT_STRLEN_MAXIMUM(int) + 1];
530 :
531 10062211 : sprintf(buf, format, n);
532 10062211 : return _add(buf, pt, ptlim);
533 : }
534 :
535 : static char *
536 11501375 : _add(const char *str, char *pt, const char *ptlim)
537 : {
538 35943289 : while (pt < ptlim && (*pt = *str++) != '\0')
539 24441914 : ++pt;
540 11501375 : return pt;
541 : }
542 :
543 : /*
544 : * POSIX and the C Standard are unclear or inconsistent about
545 : * what %C and %y do if the year is negative or exceeds 9999.
546 : * Use the convention that %C concatenated with %y yields the
547 : * same output as %Y, and that %Y contains at least 4 bytes,
548 : * with more only if necessary.
549 : */
550 :
551 : static char *
552 1437573 : _yconv(int a, int b, bool convert_top, bool convert_yy,
553 : char *pt, const char *ptlim)
554 : {
555 : int lead;
556 : int trail;
557 :
558 : #define DIVISOR 100
559 1437573 : trail = a % DIVISOR + b % DIVISOR;
560 1437573 : lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
561 1437573 : trail %= DIVISOR;
562 1437573 : if (trail < 0 && lead > 0)
563 : {
564 0 : trail += DIVISOR;
565 0 : --lead;
566 : }
567 1437573 : else if (lead < 0 && trail > 0)
568 : {
569 0 : trail -= DIVISOR;
570 0 : ++lead;
571 : }
572 1437573 : if (convert_top)
573 : {
574 1437573 : if (lead == 0 && trail < 0)
575 0 : pt = _add("-0", pt, ptlim);
576 : else
577 1437573 : pt = _conv(lead, "%02d", pt, ptlim);
578 : }
579 1437573 : if (convert_yy)
580 1437573 : pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
581 1437573 : return pt;
582 : }
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