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October 21, 2017 03:08
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Strptime from newlib cut down to parse RFC1123 dates.
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| /* | |
| * Copyright (c) 1999 Kungliga Tekniska H�gskolan | |
| * (Royal Institute of Technology, Stockholm, Sweden). | |
| * All rights reserved. | |
| * | |
| * Redistribution and use in source and binary forms, with or without | |
| * modification, are permitted provided that the following conditions | |
| * are met: | |
| * | |
| * 1. Redistributions of source code must retain the above copyright | |
| * notice, this list of conditions and the following disclaimer. | |
| * | |
| * 2. Redistributions in binary form must reproduce the above copyright | |
| * notice, this list of conditions and the following disclaimer in the | |
| * documentation and/or other materials provided with the distribution. | |
| * | |
| * 3. Neither the name of KTH nor the names of its contributors may be | |
| * used to endorse or promote products derived from this software without | |
| * specific prior written permission. | |
| * | |
| * THIS SOFTWARE IS PROVIDED BY KTH AND ITS CONTRIBUTORS ``AS IS'' AND ANY | |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KTH OR ITS CONTRIBUTORS BE | |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR | |
| * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, | |
| * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR | |
| * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF | |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ | |
| #define _GNU_SOURCE | |
| #include <stddef.h> | |
| #include <stdio.h> | |
| #include <time.h> | |
| #include <string.h> | |
| #include <strings.h> | |
| #include <ctype.h> | |
| #include <stdlib.h> | |
| #include <errno.h> | |
| #include <inttypes.h> | |
| #include <limits.h> | |
| static const char* mon[] = { | |
| "Jan", "Feb", "Mar", "Apr", "May", "Jun", | |
| "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" | |
| }; | |
| #define strtol_l(a, b, c, d) strtol(a, b, c) | |
| #define strptime_l(a, b, c, d) strptime(a, b, c) | |
| #define match_string(a, b, c) _match_string(a, b) | |
| static const int _DAYS_BEFORE_MONTH[12] = | |
| {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}; | |
| #define SET_MDAY 1 | |
| #define SET_MON 2 | |
| #define SET_YEAR 4 | |
| #define SET_WDAY 8 | |
| #define SET_YDAY 16 | |
| #define SET_YMD (SET_YEAR | SET_MON | SET_MDAY) | |
| /* | |
| * tm_year is relative this year | |
| */ | |
| const int tm_year_base = 1900; | |
| /* | |
| * Return TRUE iff `year' was a leap year. | |
| * Needed for strptime. | |
| */ | |
| static int | |
| is_leap_year (int year) | |
| { | |
| return (year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0); | |
| } | |
| /* Needed for strptime. */ | |
| static int | |
| _match_string (const char *__restrict *buf, const char * const*strs) | |
| { | |
| int i = 0; | |
| for (i = 0; strs[i] != NULL; ++i) { | |
| int len = strlen (strs[i]); | |
| if (strncasecmp (*buf, strs[i], len) == 0) { | |
| *buf += len; | |
| return i; | |
| } | |
| } | |
| return -1; | |
| } | |
| /* Needed for strptime. */ | |
| static int | |
| first_day (int year) | |
| { | |
| int ret = 4; | |
| while (--year >= 1970) | |
| ret = (ret + 365 + is_leap_year (year)) % 7; | |
| return ret; | |
| } | |
| /* | |
| * Set `timeptr' given `wnum' (week number [0, 53]) | |
| * Needed for strptime | |
| */ | |
| static void | |
| set_week_number_sun (struct tm *timeptr, int wnum) | |
| { | |
| int fday = first_day (timeptr->tm_year + tm_year_base); | |
| timeptr->tm_yday = wnum * 7 + timeptr->tm_wday - fday; | |
| if (timeptr->tm_yday < 0) { | |
| timeptr->tm_wday = fday; | |
| timeptr->tm_yday = 0; | |
| } | |
| } | |
| /* | |
| * Set `timeptr' given `wnum' (week number [0, 53]) | |
| * Needed for strptime | |
| */ | |
| static void | |
| set_week_number_mon (struct tm *timeptr, int wnum) | |
| { | |
| int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7; | |
| timeptr->tm_yday = wnum * 7 + (timeptr->tm_wday + 6) % 7 - fday; | |
| if (timeptr->tm_yday < 0) { | |
| timeptr->tm_wday = (fday + 1) % 7; | |
| timeptr->tm_yday = 0; | |
| } | |
| } | |
| /* | |
| * Set `timeptr' given `wnum' (week number [0, 53]) | |
| * Needed for strptime | |
| */ | |
| static void | |
| set_week_number_mon4 (struct tm *timeptr, int wnum) | |
| { | |
| int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7; | |
| int offset = 0; | |
| if (fday < 4) | |
| offset += 7; | |
| timeptr->tm_yday = offset + (wnum - 1) * 7 + timeptr->tm_wday - fday; | |
| if (timeptr->tm_yday < 0) { | |
| timeptr->tm_wday = fday; | |
| timeptr->tm_yday = 0; | |
| } | |
| } | |
| char * | |
| strptime (const char *buf, const char *format, struct tm *timeptr) | |
| { | |
| char c; | |
| int ymd = 0; | |
| for (; (c = *format) != '\0'; ++format) { | |
| char *s; | |
| int ret; | |
| if (isspace ((unsigned char) c)) { | |
| while (isspace ((unsigned char) *buf)) | |
| ++buf; | |
| } else if (c == '%' && format[1] != '\0') { | |
| c = *++format; | |
| if (c == 'E' || c == 'O') | |
| c = *++format; | |
| switch (c) { | |
| case 'b' : | |
| case 'h' : | |
| ret = match_string (&buf, mon, locale); | |
| if (ret < 0) | |
| return NULL; | |
| timeptr->tm_mon = ret; | |
| ymd |= SET_MON; | |
| break; | |
| case 'd' : | |
| case 'e' : | |
| ret = strtol_l (buf, &s, 10, locale); | |
| if (s == buf) | |
| return NULL; | |
| timeptr->tm_mday = ret; | |
| buf = s; | |
| ymd |= SET_MDAY; | |
| break; | |
| case 'H' : | |
| case 'k' : /* hour with leading space - GNU extension */ | |
| ret = strtol_l (buf, &s, 10, locale); | |
| if (s == buf) | |
| return NULL; | |
| timeptr->tm_hour = ret; | |
| buf = s; | |
| break; | |
| case 'M' : | |
| ret = strtol_l (buf, &s, 10, locale); | |
| if (s == buf) | |
| return NULL; | |
| timeptr->tm_min = ret; | |
| buf = s; | |
| break; | |
| case 'S' : | |
| ret = strtol_l (buf, &s, 10, locale); | |
| if (s == buf) | |
| return NULL; | |
| timeptr->tm_sec = ret; | |
| buf = s; | |
| break; | |
| case 'T' : /* %H:%M:%S */ | |
| s = strptime_l (buf, "%H:%M:%S", timeptr, locale); | |
| if (s == NULL) | |
| return NULL; | |
| buf = s; | |
| break; | |
| case 'Y' : | |
| ret = strtol_l (buf, &s, 10, locale); | |
| if (s == buf) | |
| return NULL; | |
| timeptr->tm_year = ret - tm_year_base; | |
| buf = s; | |
| ymd |= SET_YEAR; | |
| break; | |
| case '\0' : | |
| --format; | |
| /* FALLTHROUGH */ | |
| case '%' : | |
| if (*buf == '%') | |
| ++buf; | |
| else | |
| return NULL; | |
| break; | |
| default : | |
| if (*buf == '%' || *++buf == c) | |
| ++buf; | |
| else | |
| return NULL; | |
| break; | |
| } | |
| } else { | |
| if (*buf == c) | |
| ++buf; | |
| else | |
| return NULL; | |
| } | |
| } | |
| if ((ymd & SET_YMD) == SET_YMD) { | |
| /* all of tm_year, tm_mon and tm_mday, but... */ | |
| if (!(ymd & SET_YDAY)) { | |
| /* ...not tm_yday, so fill it in */ | |
| timeptr->tm_yday = _DAYS_BEFORE_MONTH[timeptr->tm_mon] | |
| + timeptr->tm_mday; | |
| if (!is_leap_year (timeptr->tm_year + tm_year_base) | |
| || timeptr->tm_mon < 2) | |
| { | |
| timeptr->tm_yday--; | |
| } | |
| ymd |= SET_YDAY; | |
| } | |
| } | |
| else if ((ymd & (SET_YEAR | SET_YDAY)) == (SET_YEAR | SET_YDAY)) { | |
| /* both of tm_year and tm_yday, but... */ | |
| if (!(ymd & SET_MON)) { | |
| /* ...not tm_mon, so fill it in, and/or... */ | |
| if (timeptr->tm_yday < _DAYS_BEFORE_MONTH[1]) | |
| timeptr->tm_mon = 0; | |
| else { | |
| int leap = is_leap_year (timeptr->tm_year + tm_year_base); | |
| int i; | |
| for (i = 2; i < 12; ++i) { | |
| if (timeptr->tm_yday < _DAYS_BEFORE_MONTH[i] + leap) | |
| break; | |
| } | |
| timeptr->tm_mon = i - 1; | |
| } | |
| } | |
| if (!(ymd & SET_MDAY)) { | |
| /* ...not tm_mday, so fill it in */ | |
| timeptr->tm_mday = timeptr->tm_yday | |
| - _DAYS_BEFORE_MONTH[timeptr->tm_mon]; | |
| if (!is_leap_year (timeptr->tm_year + tm_year_base) | |
| || timeptr->tm_mon < 2) | |
| { | |
| timeptr->tm_mday++; | |
| } | |
| } | |
| } | |
| if ((ymd & (SET_YEAR | SET_YDAY | SET_WDAY)) == (SET_YEAR | SET_YDAY)) { | |
| /* fill in tm_wday */ | |
| int fday = first_day (timeptr->tm_year + tm_year_base); | |
| timeptr->tm_wday = (fday + timeptr->tm_yday) % 7; | |
| } | |
| return (char *)buf; | |
| } |
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