| Jan Kundrát | 7f8fee0 | 2021-12-10 17:37:46 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * This comes from the musl C library which has been licensed under the permissive MIT license. |
| 3 | * |
| 4 | * Downloaded from https://git.musl-libc.org/cgit/musl/plain/src/time/strptime.c, |
| 5 | * commit 98e688a9da5e7b2925dda17a2d6820dddf1fb287. |
| 6 | * */ |
| 7 | |
| 8 | #include <stdlib.h> |
| 9 | #include <langinfo.h> |
| 10 | #include <time.h> |
| 11 | #include <ctype.h> |
| 12 | #include <stddef.h> |
| 13 | #include <string.h> |
| 14 | #include <strings.h> |
| 15 | |
| 16 | char *strptime(const char *restrict s, const char *restrict f, struct tm *restrict tm) |
| 17 | { |
| 18 | int i, w, neg, adj, min, range, *dest, dummy; |
| 19 | const char *ex; |
| 20 | size_t len; |
| 21 | int want_century = 0, century = 0, relyear = 0; |
| 22 | while (*f) { |
| 23 | if (*f != '%') { |
| 24 | if (isspace(*f)) for (; *s && isspace(*s); s++); |
| 25 | else if (*s != *f) return 0; |
| 26 | else s++; |
| 27 | f++; |
| 28 | continue; |
| 29 | } |
| 30 | f++; |
| 31 | if (*f == '+') f++; |
| 32 | if (isdigit(*f)) { |
| 33 | char *new_f; |
| 34 | w=strtoul(f, &new_f, 10); |
| 35 | f = new_f; |
| 36 | } else { |
| 37 | w=-1; |
| 38 | } |
| 39 | adj=0; |
| 40 | switch (*f++) { |
| 41 | case 'a': case 'A': |
| 42 | dest = &tm->tm_wday; |
| 43 | min = ABDAY_1; |
| 44 | range = 7; |
| 45 | goto symbolic_range; |
| 46 | case 'b': case 'B': case 'h': |
| 47 | dest = &tm->tm_mon; |
| 48 | min = ABMON_1; |
| 49 | range = 12; |
| 50 | goto symbolic_range; |
| 51 | case 'c': |
| 52 | s = strptime(s, nl_langinfo(D_T_FMT), tm); |
| 53 | if (!s) return 0; |
| 54 | break; |
| 55 | case 'C': |
| 56 | dest = ¢ury; |
| 57 | if (w<0) w=2; |
| 58 | want_century |= 2; |
| 59 | goto numeric_digits; |
| 60 | case 'd': case 'e': |
| 61 | dest = &tm->tm_mday; |
| 62 | min = 1; |
| 63 | range = 31; |
| 64 | goto numeric_range; |
| 65 | case 'D': |
| 66 | s = strptime(s, "%m/%d/%y", tm); |
| 67 | if (!s) return 0; |
| 68 | break; |
| 69 | case 'H': |
| 70 | dest = &tm->tm_hour; |
| 71 | min = 0; |
| 72 | range = 24; |
| 73 | goto numeric_range; |
| 74 | case 'I': |
| 75 | dest = &tm->tm_hour; |
| 76 | min = 1; |
| 77 | range = 12; |
| 78 | goto numeric_range; |
| 79 | case 'j': |
| 80 | dest = &tm->tm_yday; |
| 81 | min = 1; |
| 82 | range = 366; |
| 83 | adj = 1; |
| 84 | goto numeric_range; |
| 85 | case 'm': |
| 86 | dest = &tm->tm_mon; |
| 87 | min = 1; |
| 88 | range = 12; |
| 89 | adj = 1; |
| 90 | goto numeric_range; |
| 91 | case 'M': |
| 92 | dest = &tm->tm_min; |
| 93 | min = 0; |
| 94 | range = 60; |
| 95 | goto numeric_range; |
| 96 | case 'n': case 't': |
| 97 | for (; *s && isspace(*s); s++); |
| 98 | break; |
| 99 | case 'p': |
| 100 | ex = nl_langinfo(AM_STR); |
| 101 | len = strlen(ex); |
| 102 | if (!strncasecmp(s, ex, len)) { |
| 103 | tm->tm_hour %= 12; |
| 104 | s += len; |
| 105 | break; |
| 106 | } |
| 107 | ex = nl_langinfo(PM_STR); |
| 108 | len = strlen(ex); |
| 109 | if (!strncasecmp(s, ex, len)) { |
| 110 | tm->tm_hour %= 12; |
| 111 | tm->tm_hour += 12; |
| 112 | s += len; |
| 113 | break; |
| 114 | } |
| 115 | return 0; |
| 116 | case 'r': |
| 117 | s = strptime(s, nl_langinfo(T_FMT_AMPM), tm); |
| 118 | if (!s) return 0; |
| 119 | break; |
| 120 | case 'R': |
| 121 | s = strptime(s, "%H:%M", tm); |
| 122 | if (!s) return 0; |
| 123 | break; |
| 124 | case 'S': |
| 125 | dest = &tm->tm_sec; |
| 126 | min = 0; |
| 127 | range = 61; |
| 128 | goto numeric_range; |
| 129 | case 'T': |
| 130 | s = strptime(s, "%H:%M:%S", tm); |
| 131 | if (!s) return 0; |
| 132 | break; |
| 133 | case 'U': |
| 134 | case 'W': |
| 135 | /* Throw away result, for now. (FIXME?) */ |
| 136 | dest = &dummy; |
| 137 | min = 0; |
| 138 | range = 54; |
| 139 | goto numeric_range; |
| 140 | case 'w': |
| 141 | dest = &tm->tm_wday; |
| 142 | min = 0; |
| 143 | range = 7; |
| 144 | goto numeric_range; |
| 145 | case 'x': |
| 146 | s = strptime(s, nl_langinfo(D_FMT), tm); |
| 147 | if (!s) return 0; |
| 148 | break; |
| 149 | case 'X': |
| 150 | s = strptime(s, nl_langinfo(T_FMT), tm); |
| 151 | if (!s) return 0; |
| 152 | break; |
| 153 | case 'y': |
| 154 | dest = &relyear; |
| 155 | w = 2; |
| 156 | want_century |= 1; |
| 157 | goto numeric_digits; |
| 158 | case 'Y': |
| 159 | dest = &tm->tm_year; |
| 160 | if (w<0) w=4; |
| 161 | adj = 1900; |
| 162 | want_century = 0; |
| 163 | goto numeric_digits; |
| 164 | case '%': |
| 165 | if (*s++ != '%') return 0; |
| 166 | break; |
| 167 | default: |
| 168 | return 0; |
| 169 | numeric_range: |
| 170 | if (!isdigit(*s)) return 0; |
| 171 | *dest = 0; |
| 172 | for (i=1; i<=min+range && isdigit(*s); i*=10) |
| 173 | *dest = *dest * 10 + *s++ - '0'; |
| 174 | if (*dest - min >= (unsigned)range) return 0; |
| 175 | *dest -= adj; |
| 176 | switch((char *)dest - (char *)tm) { |
| 177 | case offsetof(struct tm, tm_yday): |
| 178 | ; |
| 179 | } |
| 180 | goto update; |
| 181 | numeric_digits: |
| 182 | neg = 0; |
| 183 | if (*s == '+') s++; |
| 184 | else if (*s == '-') neg=1, s++; |
| 185 | if (!isdigit(*s)) return 0; |
| 186 | for (*dest=i=0; i<w && isdigit(*s); i++) |
| 187 | *dest = *dest * 10 + *s++ - '0'; |
| 188 | if (neg) *dest = -*dest; |
| 189 | *dest -= adj; |
| 190 | goto update; |
| 191 | symbolic_range: |
| 192 | for (i=2*range-1; i>=0; i--) { |
| 193 | ex = nl_langinfo(min+i); |
| 194 | len = strlen(ex); |
| 195 | if (strncasecmp(s, ex, len)) continue; |
| 196 | s += len; |
| 197 | *dest = i % range; |
| 198 | break; |
| 199 | } |
| 200 | if (i<0) return 0; |
| 201 | goto update; |
| 202 | update: |
| 203 | //FIXME |
| 204 | ; |
| 205 | } |
| 206 | } |
| 207 | if (want_century) { |
| 208 | tm->tm_year = relyear; |
| 209 | if (want_century & 2) tm->tm_year += century * 100 - 1900; |
| 210 | else if (tm->tm_year <= 68) tm->tm_year += 100; |
| 211 | } |
| 212 | return (char *)s; |
| 213 | } |