stdio/fdopen.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1990, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * This code is derived from software contributed to Berkeley by
  30  * Chris Torek.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  */
  60
  61
  62 #include <sys/types.h>
  63 #include <fcntl.h>
  64 #include <unistd.h>
  65 #include <stdio.h>
  66 #include <errno.h>
  67 #include "local.h"
  68
  69 FILE *
  70 fdopen(fd, mode)
  71         int fd;
  72         const char *mode;
  73 {
  74         register FILE *fp;
  75         static int nofile;
  76         int flags, oflags, fdflags, tmp;
  77
  78         if (nofile == 0)
  79                 nofile = getdtablesize();
  80
  81         if ((flags = __sflags(mode, &oflags)) == 0)
  82                 return (NULL);
  83
  84         /* Make sure the mode the user wants is a subset of the actual mode. */
  85         if ((fdflags = fcntl(fd, F_GETFL, 0)) < 0)
  86                 return (NULL);
  87         tmp = fdflags & O_ACCMODE;
  88         if (tmp != O_RDWR && (tmp != (oflags & O_ACCMODE))) {
  89                 errno = EINVAL;
  90                 return (NULL);
  91         }
  92
  93         if ((fp = __sfp()) == NULL)
  94                 return (NULL);
  95         fp->_flags = flags;
  96         /*
  97          * If opened for appending, but underlying descriptor does not have
  98          * O_APPEND bit set, assert __SAPP so that __swrite() will lseek to
  99          * end before each write.
 100          */
 101         if ((oflags & O_APPEND) && !(fdflags & O_APPEND))
 102                 fp->_flags |= __SAPP;
 103         fp->_file = fd;
 104         fp->_cookie = fp;
 105         fp->_read = __sread;
 106         fp->_write = __swrite;
 107         fp->_seek = __sseek;
 108         fp->_close = __sclose;
 109         return (fp);
 110 }