1#include <stdio.h>
2#include <stdlib.h>
3#include <string.h>
4#include <langinfo.h>
5#include <locale.h>
6#include <ctype.h>
7#include <time.h>
8#include <limits.h>
9#include "locale_impl.h"
10#include "time_impl.h"
11
12static int is_leap(int y)
13{
14 /* Avoid overflow */
15 if (y>INT_MAX-1900) y -= 2000;
16 y += 1900;
17 return !(y%4) && ((y%100) || !(y%400));
18}
19
20static int week_num(const struct tm *tm)
21{
22 int val = (tm->tm_yday + 7U - (tm->tm_wday+6U)%7) / 7;
23 /* If 1 Jan is just 1-3 days past Monday,
24 * the previous week is also in this year. */
25 if ((tm->tm_wday + 371U - tm->tm_yday - 2) % 7 <= 2)
26 val++;
27 if (!val) {
28 val = 52;
29 /* If 31 December of prev year a Thursday,
30 * or Friday of a leap year, then the
31 * prev year has 53 weeks. */
32 int dec31 = (tm->tm_wday + 7U - tm->tm_yday - 1) % 7;
33 if (dec31 == 4 || (dec31 == 5 && is_leap(tm->tm_year%400-1)))
34 val++;
35 } else if (val == 53) {
36 /* If 1 January is not a Thursday, and not
37 * a Wednesday of a leap year, then this
38 * year has only 52 weeks. */
39 int jan1 = (tm->tm_wday + 371U - tm->tm_yday) % 7;
40 if (jan1 != 4 && (jan1 != 3 || !is_leap(tm->tm_year)))
41 val = 1;
42 }
43 return val;
44}
45
46const char *__strftime_fmt_1(char (*s)[100], size_t *l, int f, const struct tm *tm, locale_t loc, int pad)
47{
48 nl_item item;
49 long long val;
50 const char *fmt = "-";
51 int width = 2, def_pad = '0';
52
53 switch (f) {
54 case 'a':
55 if (tm->tm_wday > 6U) goto string;
56 item = ABDAY_1 + tm->tm_wday;
57 goto nl_strcat;
58 case 'A':
59 if (tm->tm_wday > 6U) goto string;
60 item = DAY_1 + tm->tm_wday;
61 goto nl_strcat;
62 case 'h':
63 case 'b':
64 if (tm->tm_mon > 11U) goto string;
65 item = ABMON_1 + tm->tm_mon;
66 goto nl_strcat;
67 case 'B':
68 if (tm->tm_mon > 11U) goto string;
69 item = MON_1 + tm->tm_mon;
70 goto nl_strcat;
71 case 'c':
72 item = D_T_FMT;
73 goto nl_strftime;
74 case 'C':
75 val = (1900LL+tm->tm_year) / 100;
76 goto number;
77 case 'e':
78 def_pad = '_';
79 case 'd':
80 val = tm->tm_mday;
81 goto number;
82 case 'D':
83 fmt = "%m/%d/%y";
84 goto recu_strftime;
85 case 'F':
86 fmt = "%Y-%m-%d";
87 goto recu_strftime;
88 case 'g':
89 case 'G':
90 val = tm->tm_year + 1900LL;
91 if (tm->tm_yday < 3 && week_num(tm) != 1) val--;
92 else if (tm->tm_yday > 360 && week_num(tm) == 1) val++;
93 if (f=='g') val %= 100;
94 else width = 4;
95 goto number;
96 case 'H':
97 val = tm->tm_hour;
98 goto number;
99 case 'I':
100 val = tm->tm_hour;
101 if (!val) val = 12;
102 else if (val > 12) val -= 12;
103 goto number;
104 case 'j':
105 val = tm->tm_yday+1;
106 width = 3;
107 goto number;
108 case 'm':
109 val = tm->tm_mon+1;
110 goto number;
111 case 'M':
112 val = tm->tm_min;
113 goto number;
114 case 'n':
115 *l = 1;
116 return "\n";
117 case 'p':
118 item = tm->tm_hour >= 12 ? PM_STR : AM_STR;
119 goto nl_strcat;
120 case 'r':
121 item = T_FMT_AMPM;
122 goto nl_strftime;
123 case 'R':
124 fmt = "%H:%M";
125 goto recu_strftime;
126 case 's':
127 val = __tm_to_secs(tm) - tm->__tm_gmtoff;
128 width = 1;
129 goto number;
130 case 'S':
131 val = tm->tm_sec;
132 goto number;
133 case 't':
134 *l = 1;
135 return "\t";
136 case 'T':
137 fmt = "%H:%M:%S";
138 goto recu_strftime;
139 case 'u':
140 val = tm->tm_wday ? tm->tm_wday : 7;
141 width = 1;
142 goto number;
143 case 'U':
144 val = (tm->tm_yday + 7U - tm->tm_wday) / 7;
145 goto number;
146 case 'W':
147 val = (tm->tm_yday + 7U - (tm->tm_wday+6U)%7) / 7;
148 goto number;
149 case 'V':
150 val = week_num(tm);
151 goto number;
152 case 'w':
153 val = tm->tm_wday;
154 width = 1;
155 goto number;
156 case 'x':
157 item = D_FMT;
158 goto nl_strftime;
159 case 'X':
160 item = T_FMT;
161 goto nl_strftime;
162 case 'y':
163 val = (tm->tm_year + 1900LL) % 100;
164 if (val < 0) val = -val;
165 goto number;
166 case 'Y':
167 val = tm->tm_year + 1900LL;
168 if (val >= 10000) {
169 *l = snprintf(*s, sizeof *s, "+%lld", val);
170 return *s;
171 }
172 width = 4;
173 goto number;
174 case 'z':
175 if (tm->tm_isdst < 0) {
176 *l = 0;
177 return "";
178 }
179#ifdef __wasilibc_unmodified_upstream // wasi-libc's __tm_gmtoff is an int
180 *l = snprintf(*s, sizeof *s, "%+.4ld",
181#else
182 *l = snprintf(*s, sizeof *s, "%+.4d",
183#endif
184 tm->__tm_gmtoff/3600*100 + tm->__tm_gmtoff%3600/60);
185 return *s;
186 case 'Z':
187 if (tm->tm_isdst < 0) {
188 *l = 0;
189 return "";
190 }
191 fmt = __tm_to_tzname(tm);
192 goto string;
193 case '%':
194 *l = 1;
195 return "%";
196 default:
197 return 0;
198 }
199number:
200 switch (pad ? pad : def_pad) {
201 case '-': *l = snprintf(*s, sizeof *s, "%lld", val); break;
202 case '_': *l = snprintf(*s, sizeof *s, "%*lld", width, val); break;
203 case '0':
204 default: *l = snprintf(*s, sizeof *s, "%0*lld", width, val); break;
205 }
206 return *s;
207nl_strcat:
208 fmt = __nl_langinfo_l(item, loc);
209string:
210 *l = strlen(fmt);
211 return fmt;
212nl_strftime:
213 fmt = __nl_langinfo_l(item, loc);
214recu_strftime:
215 *l = __strftime_l(*s, sizeof *s, fmt, tm, loc);
216 if (!*l) return 0;
217 return *s;
218}
219
220size_t __strftime_l(char *restrict s, size_t n, const char *restrict f, const struct tm *restrict tm, locale_t loc)
221{
222 size_t l, k;
223 char buf[100];
224 char *p;
225 const char *t;
226 int pad, plus;
227 unsigned long width;
228 for (l=0; l<n; f++) {
229 if (!*f) {
230 s[l] = 0;
231 return l;
232 }
233 if (*f != '%') {
234 s[l++] = *f;
235 continue;
236 }
237 f++;
238 pad = 0;
239 if (*f == '-' || *f == '_' || *f == '0') pad = *f++;
240 if ((plus = (*f == '+'))) f++;
241 if (isdigit(*f)) {
242 width = strtoul(f, &p, 10);
243 } else {
244 width = 0;
245 p = (void *)f;
246 }
247 if (*p == 'C' || *p == 'F' || *p == 'G' || *p == 'Y') {
248 if (!width && p!=f) width = 1;
249 } else {
250 width = 0;
251 }
252 f = p;
253 if (*f == 'E' || *f == 'O') f++;
254 t = __strftime_fmt_1(&buf, &k, *f, tm, loc, pad);
255 if (!t) break;
256 if (width) {
257 /* Trim off any sign and leading zeros, then
258 * count remaining digits to determine behavior
259 * for the + flag. */
260 if (*t=='+' || *t=='-') t++, k--;
261 for (; *t=='0' && t[1]-'0'<10U; t++, k--);
262 if (width < k) width = k;
263 size_t d;
264 for (d=0; t[d]-'0'<10U; d++);
265 if (tm->tm_year < -1900) {
266 s[l++] = '-';
267 width--;
268 } else if (plus && d+(width-k) >= (*p=='C'?3:5)) {
269 s[l++] = '+';
270 width--;
271 }
272 for (; width > k && l < n; width--)
273 s[l++] = '0';
274 }
275 if (k > n-l) k = n-l;
276 memcpy(s+l, t, k);
277 l += k;
278 }
279 if (n) {
280 if (l==n) l=n-1;
281 s[l] = 0;
282 }
283 return 0;
284}
285
286size_t strftime(char *restrict s, size_t n, const char *restrict f, const struct tm *restrict tm)
287{
288 return __strftime_l(s, n, f, tm, CURRENT_LOCALE);
289}
290
291weak_alias(__strftime_l, strftime_l);