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  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * $FreeBSD: src/lib/libc/stdio/fopen.c,v 1.3.2.1 2001/03/05 10:53:51 obrien Exp $
  37  * $DragonFly: src/lib/libc/stdio/fopen.c,v 1.6 2005/11/20 11:07:30 swildner Exp $
  38  *
  39  * @(#)fopen.c  8.1 (Berkeley) 6/4/93
  40  */
  41
  42 #include "namespace.h"
  43 #include <sys/types.h>
  44 #include <sys/stat.h>
  45 #include <fcntl.h>
  46 #include <stdio.h>
  47 #include <errno.h>
  48 #include "un-namespace.h"
  49
  50 #include "local.h"
  51 #include "priv_stdio.h"
  52
  53 FILE *
  54 fopen(const char *file, const char *mode)
  55 {
  56         FILE *fp;
  57         int f;
  58         int flags, oflags;
  59
  60         if ((flags = __sflags(mode, &oflags)) == 0)
  61                 return (NULL);
  62         if ((fp = __sfp()) == NULL)
  63                 return (NULL);
  64         if ((f = _open(file, oflags, DEFFILEMODE)) < 0) {
  65                 fp->pub._flags = 0;                     /* release */
  66                 return (NULL);
  67         }
  68         fp->pub._fileno = f;
  69         fp->pub._flags = flags;
  70         fp->_cookie = fp;
  71         fp->_read = __sread;
  72         fp->_write = __swrite;
  73         fp->_seek = __sseek;
  74         fp->_close = __sclose;
  75         /* fp->_lock = NULL; */
  76         /*
  77          * When opening in append mode, even though we use O_APPEND,
  78          * we need to seek to the end so that ftell() gets the right
  79          * answer.  If the user then alters the seek pointer, or
  80          * the file extends, this will fail, but there is not much
  81          * we can do about this.  (We could set __SAPP and check in
  82          * fseek and ftell.)
  83          */
  84         if (oflags & O_APPEND)
  85                 __sseek((void *)fp, (fpos_t)0, SEEK_END);
  86         return (fp);
  87 }