lib/libc/stdio/fopen.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Chris Torek.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * @(#)fopen.c  8.1 (Berkeley) 6/4/93
  33  * $FreeBSD: src/lib/libc/stdio/fopen.c,v 1.14 2008/04/22 17:03:32 jhb Exp $
  34  * $DragonFly: src/lib/libc/stdio/fopen.c,v 1.6 2005/11/20 11:07:30 swildner Exp $
  35  */
  36
  37 #include "namespace.h"
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <fcntl.h>
  41 #include <stdio.h>
  42 #include <errno.h>
  43 #include "un-namespace.h"
  44
  45 #include "local.h"
  46 #include "priv_stdio.h"
  47
  48 FILE *
  49 fopen(const char * __restrict file, const char * __restrict mode)
  50 {
  51         FILE *fp;
  52         int f;
  53         int flags, oflags;
  54
  55         if ((flags = __sflags(mode, &oflags)) == 0)
  56                 return (NULL);
  57         if ((fp = __sfp()) == NULL)
  58                 return (NULL);
  59         if ((f = _open(file, oflags, DEFFILEMODE)) < 0) {
  60                 fp->pub._flags = 0;             /* release */
  61                 return (NULL);
  62         }
  63         fp->pub._fileno = f;
  64         fp->pub._flags = flags;
  65         fp->_cookie = fp;
  66         fp->_read = __sread;
  67         fp->_write = __swrite;
  68         fp->_seek = __sseek;
  69         fp->_close = __sclose;
  70         /*
  71          * When opening in append mode, even though we use O_APPEND,
  72          * we need to seek to the end so that ftell() gets the right
  73          * answer.  If the user then alters the seek pointer, or
  74          * the file extends, this will fail, but there is not much
  75          * we can do about this.  (We could set __SAPP and check in
  76          * fseek and ftell.)
  77          */
  78         if (oflags & O_APPEND)
  79                 _sseek(fp, (fpos_t)0, SEEK_END);
  80         return (fp);
  81 }