cosmopolitan/net/http/formathttpdatetime.c

68 lines
2.9 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/str.h"
#include "libc/time/struct/tm.h"
#include "libc/time/time.h"
#include "net/http/http.h"
/**
* Formats HTTP timestamp, e.g.
*
* Sun, 04 Oct 2020 19:50:10 GMT
*
* @param tm must be zulu see gmtime_r() and nowl()
* @see ParseHttpDateTime()
*/
char *FormatHttpDateTime(char p[hasatleast 30], struct tm *tm) {
unsigned i;
p = mempcpy(p, kWeekdayNameShort[tm->tm_wday], 3);
*p++ = ',';
*p++ = ' ';
i = tm->tm_mday;
*p++ = '0' + i / 10;
*p++ = '0' + i % 10;
*p++ = ' ';
p = mempcpy(p, kMonthNameShort[tm->tm_mon], 3);
*p++ = ' ';
i = tm->tm_year + 1900;
*p++ = '0' + i / 1000;
*p++ = '0' + i / 100 % 10;
*p++ = '0' + i / 10 % 10;
*p++ = '0' + i % 10;
*p++ = ' ';
i = tm->tm_hour;
*p++ = '0' + i / 10;
*p++ = '0' + i % 10;
*p++ = ':';
i = tm->tm_min;
*p++ = '0' + i / 10;
*p++ = '0' + i % 10;
*p++ = ':';
i = tm->tm_sec;
*p++ = '0' + i / 10;
*p++ = '0' + i % 10;
*p++ = ' ';
*p++ = 'G';
*p++ = 'M';
*p++ = 'T';
*p = '\0';
return p;
}