lib/libc/stdio/fdopen.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/fdopen.c,v 1.3 2000/01/27 23:06:44 jasone Exp $
  37  * $DragonFly: src/lib/libc/stdio/fdopen.c,v 1.6 2005/07/23 20:23:05 joerg Exp $
  38  *
  39  * @(#)fdopen.c 8.1 (Berkeley) 6/4/93
  40  */
  41
  42 #include "namespace.h"
  43 #include <sys/types.h>
  44 #include <fcntl.h>
  45 #include <unistd.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 fdopen(int fd, const char *mode)
  55 {
  56         FILE *fp;
  57         static int nofile;
  58         int flags, oflags, fdflags, tmp;
  59
  60         if (nofile == 0)
  61                 nofile = getdtablesize();
  62
  63         if ((flags = __sflags(mode, &oflags)) == 0)
  64                 return (NULL);
  65
  66         /* Make sure the mode the user wants is a subset of the actual mode. */
  67         if ((fdflags = _fcntl(fd, F_GETFL, 0)) < 0)
  68                 return (NULL);
  69         tmp = fdflags & O_ACCMODE;
  70         if (tmp != O_RDWR && (tmp != (oflags & O_ACCMODE))) {
  71                 errno = EINVAL;
  72                 return (NULL);
  73         }
  74
  75         if ((fp = __sfp()) == NULL)
  76                 return (NULL);
  77         fp->pub._flags = flags;
  78         /*
  79          * If opened for appending, but underlying descriptor does not have
  80          * O_APPEND bit set, assert __SAPP so that __swrite() will lseek to
  81          * end before each write.
  82          */
  83         if ((oflags & O_APPEND) && !(fdflags & O_APPEND))
  84                 fp->pub._flags |= __SAPP;
  85         fp->pub._fileno = fd;
  86         fp->_cookie = fp;
  87         fp->_read = __sread;
  88         fp->_write = __swrite;
  89         fp->_seek = __sseek;
  90         fp->_close = __sclose;
  91         return (fp);
  92 }