| Elliott Hughes | 9d3c2dd | 2014-04-18 13:13:04 -0700 | [diff] [blame^] | 1 | /* $OpenBSD: fread.c,v 1.11 2009/11/21 09:53:44 guenther 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 <string.h> |
| 36 | #include "local.h" |
| 37 | |
| 38 | size_t |
| 39 | fread(void *buf, size_t size, size_t count, FILE *fp) |
| 40 | { |
| 41 | size_t resid; |
| 42 | char *p; |
| 43 | int r; |
| 44 | size_t total; |
| 45 | |
| 46 | /* |
| 47 | * ANSI and SUSv2 require a return value of 0 if size or count are 0. |
| 48 | */ |
| 49 | if ((resid = count * size) == 0) |
| 50 | return (0); |
| 51 | FLOCKFILE(fp); |
| 52 | _SET_ORIENTATION(fp, -1); |
| 53 | if (fp->_r < 0) |
| 54 | fp->_r = 0; |
| 55 | total = resid; |
| 56 | p = buf; |
| 57 | while (resid > (r = fp->_r)) { |
| 58 | (void)memcpy((void *)p, (void *)fp->_p, (size_t)r); |
| 59 | fp->_p += r; |
| 60 | /* fp->_r = 0 ... done in __srefill */ |
| 61 | p += r; |
| 62 | resid -= r; |
| 63 | if (__srefill(fp)) { |
| 64 | /* no more input: return partial result */ |
| 65 | FUNLOCKFILE(fp); |
| 66 | return ((total - resid) / size); |
| 67 | } |
| 68 | } |
| 69 | (void)memcpy((void *)p, (void *)fp->_p, resid); |
| 70 | fp->_r -= resid; |
| 71 | fp->_p += resid; |
| 72 | FUNLOCKFILE(fp); |
| 73 | return (count); |
| 74 | } |