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      1 /*	$OpenBSD: funopen.c,v 1.8 2005/08/08 08:05:36 espie Exp $ */
      2 /*-
      3  * Copyright (c) 1990, 1993
      4  *	The Regents of the University of California.  All rights reserved.
      5  *
      6  * This code is derived from software contributed to Berkeley by
      7  * Chris Torek.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #include <stdio.h>
     35 #include <errno.h>
     36 #include "local.h"
     37 
     38 FILE *
     39 funopen(const void *cookie, int (*readfn)(void *, char *, int),
     40 	int (*writefn)(void *, const char *, int),
     41 	fpos_t (*seekfn)(void *, fpos_t, int), int (*closefn)(void *))
     42 {
     43 	FILE *fp;
     44 	int flags;
     45 
     46 	if (readfn == NULL) {
     47 		if (writefn == NULL) {		/* illegal */
     48 			errno = EINVAL;
     49 			return (NULL);
     50 		} else
     51 			flags = __SWR;		/* write only */
     52 	} else {
     53 		if (writefn == NULL)
     54 			flags = __SRD;		/* read only */
     55 		else
     56 			flags = __SRW;		/* read-write */
     57 	}
     58 	if ((fp = __sfp()) == NULL)
     59 		return (NULL);
     60 	fp->_flags = flags;
     61 	fp->_file = -1;
     62 	fp->_cookie = (void *)cookie;		/* SAFE: cookie not modified */
     63 	fp->_read = readfn;
     64 	fp->_write = writefn;
     65 	fp->_seek = seekfn;
     66 	fp->_close = closefn;
     67 	return (fp);
     68 }
     69