funopen.c revision 1.2
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * 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 37#if defined(LIBC_SCCS) && !defined(lint) 38/*static char sccsid[] = "from: @(#)funopen.c 5.2 (Berkeley) 2/5/91";*/ 39static char rcsid[] = "$Id: funopen.c,v 1.2 1993/08/01 18:38:52 mycroft Exp $"; 40#endif /* LIBC_SCCS and not lint */ 41 42#include <stdio.h> 43#include <errno.h> 44#include "local.h" 45 46FILE * 47funopen(cookie, readfn, writefn, seekfn, closefn) 48 const void *cookie; 49 int (*readfn)(), (*writefn)(); 50#if __STDC__ 51 fpos_t (*seekfn)(void *cookie, fpos_t off, int whence); 52#else 53 fpos_t (*seekfn)(); 54#endif 55 int (*closefn)(); 56{ 57 register FILE *fp; 58 int flags; 59 60 if (readfn == NULL) { 61 if (writefn == NULL) { /* illegal */ 62 errno = EINVAL; 63 return (NULL); 64 } else 65 flags = __SWR; /* write only */ 66 } else { 67 if (writefn == NULL) 68 flags = __SRD; /* read only */ 69 else 70 flags = __SRW; /* read-write */ 71 } 72 if ((fp = __sfp()) == NULL) 73 return (NULL); 74 fp->_flags = flags; 75 fp->_file = -1; 76 fp->_cookie = (void *)cookie; 77 fp->_read = readfn; 78 fp->_write = writefn; 79 fp->_seek = seekfn; 80 fp->_close = closefn; 81 return (fp); 82} 83