funopen.c (2886B)
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 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char rcsid[] = "$OpenBSD: funopen.c,v 1.3 1997/07/25 20:30:09 mickey Exp $"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <stdio.h> 42 #include <errno.h> 43 #include "local.h" 44 45 FILE * 46 funopen(cookie, readfn, writefn, seekfn, closefn) 47 const void *cookie; 48 int (*readfn)(), (*writefn)(); 49 #ifdef __STDC__ 50 fpos_t (*seekfn)(void *cookie, fpos_t off, int whence); 51 #else 52 fpos_t (*seekfn)(); 53 #endif 54 int (*closefn)(); 55 { 56 register FILE *fp; 57 int flags; 58 59 if (readfn == NULL) { 60 if (writefn == NULL) { /* illegal */ 61 errno = EINVAL; 62 return (NULL); 63 } else 64 flags = __SWR; /* write only */ 65 } else { 66 if (writefn == NULL) 67 flags = __SRD; /* read only */ 68 else 69 flags = __SRW; /* read-write */ 70 } 71 if ((fp = __sfp()) == NULL) 72 return (NULL); 73 fp->_flags = flags; 74 fp->_file = -1; 75 fp->_cookie = (void *)cookie; 76 fp->_read = readfn; 77 fp->_write = writefn; 78 fp->_seek = seekfn; 79 fp->_close = closefn; 80 return (fp); 81 }