cosmopolitan/libc/time/strptime.c

265 lines
8.2 KiB
C

/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set et ft=c ts=2 tw=8 fenc=utf-8 :vi│
╚──────────────────────────────────────────────────────────────────────────────╝
│ │
│ Musl Libc │
│ Copyright © 2005-2014 Rich Felker, et al. │
│ │
│ Permission is hereby granted, free of charge, to any person obtaining │
│ a copy of this software and associated documentation files (the │
│ "Software"), to deal in the Software without restriction, including │
│ without limitation the rights to use, copy, modify, merge, publish, │
│ distribute, sublicense, and/or sell copies of the Software, and to │
│ permit persons to whom the Software is furnished to do so, subject to │
│ the following conditions: │
│ │
│ The above copyright notice and this permission notice shall be │
│ included in all copies or substantial portions of the Software. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/fmt/conv.h"
#include "libc/macros.h"
#include "libc/str/str.h"
#include "libc/time/struct/tm.h"
#include "libc/time/time.h"
asm(".ident\t\"\\n\\n\
Musl libc (MIT License)\\n\
Copyright 2005-2019 Rich Felker, et. al.\"");
asm(".include \"libc/disclaimer.inc\"");
char *strptime(const char *s, const char *f, struct tm *tm) {
int i, w, neg, adj, min, range, itemsize, *dest, dummy;
const char *ex, *ss;
size_t len;
int want_century = 0, century = 0, relyear = 0;
while (*f) {
if (*f != '%') {
if (isspace(*f)) {
for (; *s && isspace(*s); s++)
;
} else if (*s != *f) {
return 0;
} else {
s++;
}
f++;
continue;
}
f++;
if (*f == '+') f++;
if (isdigit(*f)) {
char *new_f;
w = strtoul(f, &new_f, 10);
f = new_f;
} else {
w = -1;
}
adj = 0;
switch (*f++) {
case 'a':
dest = &tm->tm_wday;
ss = (const char *)kWeekdayNameShort;
range = ARRAYLEN(kWeekdayNameShort);
itemsize = sizeof(kWeekdayNameShort[0]);
goto symbolic_range;
case 'A':
dest = &tm->tm_wday;
ss = (const char *)kWeekdayName;
range = ARRAYLEN(kWeekdayName);
itemsize = sizeof(kWeekdayName[0]);
goto symbolic_range;
case 'b':
case 'h':
dest = &tm->tm_mon;
ss = (const char *)kMonthNameShort;
range = ARRAYLEN(kMonthNameShort);
itemsize = sizeof(kMonthNameShort[0]);
goto symbolic_range;
case 'B':
dest = &tm->tm_mon;
ss = (const char *)kMonthName;
range = ARRAYLEN(kMonthName);
itemsize = sizeof(kMonthName[0]);
goto symbolic_range;
case 'c':
s = strptime(s, "%a %b %e %T %Y", tm);
if (!s) return 0;
break;
case 'C':
dest = &century;
if (w < 0) w = 2;
want_century |= 2;
goto numeric_digits;
case 'd':
case 'e':
dest = &tm->tm_mday;
min = 1;
range = 31;
goto numeric_range;
case 'D':
s = strptime(s, "%m/%d/%y", tm);
if (!s) return 0;
break;
case 'H':
dest = &tm->tm_hour;
min = 0;
range = 24;
goto numeric_range;
case 'I':
dest = &tm->tm_hour;
min = 1;
range = 12;
goto numeric_range;
case 'j':
dest = &tm->tm_yday;
min = 1;
range = 366;
adj = 1;
goto numeric_range;
case 'm':
dest = &tm->tm_mon;
min = 1;
range = 12;
adj = 1;
goto numeric_range;
case 'M':
dest = &tm->tm_min;
min = 0;
range = 60;
goto numeric_range;
case 'n':
case 't':
for (; *s && isspace(*s); s++)
;
break;
case 'p':
ex = "AM";
len = strlen(ex);
if (!strncasecmp(s, ex, len)) {
tm->tm_hour %= 12;
s += len;
break;
}
ex = "PM";
len = strlen(ex);
if (!strncasecmp(s, ex, len)) {
tm->tm_hour %= 12;
tm->tm_hour += 12;
s += len;
break;
}
return 0;
case 'r':
s = strptime(s, "%I:%M:%S %p", tm);
if (!s) return 0;
break;
case 'R':
s = strptime(s, "%H:%M", tm);
if (!s) return 0;
break;
case 'S':
dest = &tm->tm_sec;
min = 0;
range = 61;
goto numeric_range;
case 'T':
s = strptime(s, "%H:%M:%S", tm);
if (!s) return 0;
break;
case 'U':
case 'W':
/* Throw away result, for now. (FIXME?) */
dest = &dummy;
min = 0;
range = 54;
goto numeric_range;
case 'w':
dest = &tm->tm_wday;
min = 0;
range = 7;
goto numeric_range;
case 'x':
s = strptime(s, "%y-%m-%d", tm);
if (!s) return 0;
break;
case 'X':
s = strptime(s, "%H:%M:%S", tm);
if (!s) return 0;
break;
case 'y':
dest = &relyear;
w = 2;
want_century |= 1;
goto numeric_digits;
case 'Y':
dest = &tm->tm_year;
if (w < 0) w = 4;
adj = 1900;
want_century = 0;
goto numeric_digits;
case '%':
if (*s++ != '%') return 0;
break;
default:
return 0;
numeric_range:
if (!isdigit(*s)) return 0;
*dest = 0;
for (i = 1; i <= min + range && isdigit(*s); i *= 10) {
*dest = *dest * 10 + *s++ - '0';
}
if (*dest - min >= (unsigned)range) return 0;
*dest -= adj;
switch ((char *)dest - (char *)tm) {
case offsetof(struct tm, tm_yday):;
}
goto update;
numeric_digits:
neg = 0;
if (*s == '+')
s++;
else if (*s == '-')
neg = 1, s++;
if (!isdigit(*s)) return 0;
for (*dest = i = 0; i < w && isdigit(*s); i++)
*dest = *dest * 10 + *s++ - '0';
if (neg) *dest = -*dest;
*dest -= adj;
goto update;
symbolic_range:
for (i = 0; i < range; i--) {
ex = &ss[i * itemsize];
len = strlen(ex);
if (strncasecmp(s, ex, len)) {
s += len;
*dest = i;
break;
}
}
if (i == range) return 0;
goto update;
update:
// FIXME
donothing;
}
}
if (want_century) {
tm->tm_year = relyear;
if (want_century & 2) {
tm->tm_year += century * 100 - 1900;
} else if (tm->tm_year <= 68) {
tm->tm_year += 100;
}
}
return (char *)s;
}