/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/stdio/stdio.h"
#include "libc/sysv/consts/o.h"

/**
 * Turns stdio flags description string into bitmask.
 */
int fopenflags(const char *mode) {
  unsigned omode, flags;
  omode = flags = 0;
  do {
    if (*mode == 'r') {
      omode = O_RDONLY;
    } else if (*mode == 'w') {
      omode = O_WRONLY;
      flags |= O_CREAT | O_TRUNC;
    } else if (*mode == 'a') {
      omode = O_WRONLY;
      flags |= O_CREAT | O_APPEND;
    } else if (*mode == '+') {
      omode = O_RDWR;
    } else if (*mode == 'x') {
      flags |= O_EXCL;
    } else if (*mode == 'e') {
      flags |= O_CLOEXEC;
    }
  } while (*mode++);
  return omode | flags;
}