/*-*- 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/zip.h"

uint8_t *zipfindcentraldir(const uint8_t *map, size_t mapsize) {
  const uint8_t *p, *pe;
  for (p = map + mapsize - kZipCdirHdrMinSize,
      pe = mapsize > 65536 + kZipCdirHdrMinSize
               ? map + mapsize - 65536 - kZipCdirHdrMinSize
               : map;
       p >= pe; --p) {
    if (ZIP_CDIR_MAGIC(p) == kZipCdirHdrMagic) {
      return (/*unconst*/ uint8_t *)p;
    }
  }
  return NULL;
}