lib/libc/stdio/funopen.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. 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  * @(#)funopen.c        8.1 (Berkeley) 6/4/93
  33  * $FreeBSD: src/lib/libc/stdio/funopen.c,v 1.6 2007/01/09 00:28:06 imp Exp $
  34  */
  35
  36 #include <stdio.h>
  37 #include <errno.h>
  38
  39 #include "local.h"
  40
  41 FILE *
  42 funopen(const void *cookie, int (*readfn)(void *, char *, int),
  43         int (*writefn)(void *, const char *, int),
  44         fpos_t (*seekfn)(void *, fpos_t, int), int (*closefn)(void *))
  45 {
  46         FILE *fp;
  47         int flags;
  48
  49         if (readfn == NULL) {
  50                 if (writefn == NULL) {          /* illegal */
  51                         errno = EINVAL;
  52                         return (NULL);
  53                 } else
  54                         flags = __SWR;          /* write only */
  55         } else {
  56                 if (writefn == NULL)
  57                         flags = __SRD;          /* read only */
  58                 else
  59                         flags = __SRW;          /* read-write */
  60         }
  61         if ((fp = __sfp()) == NULL)
  62                 return (NULL);
  63         fp->pub._flags = flags;
  64         fp->pub._fileno = -1;
  65         fp->_cookie = (void *)cookie;
  66         fp->_read = readfn;
  67         fp->_write = writefn;
  68         fp->_seek = seekfn;
  69         fp->_close = closefn;
  70         return (fp);
  71 }