Remove building with NOCRYPTO option
[minix.git] / lib / libc / stdio / fread.c
blobef3b5ef1190e090c5afc86464feb732ccf71dc8a
1 /* $NetBSD: fread.c,v 1.22 2012/03/15 18:22:30 christos Exp $ */
3 /*-
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
35 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)fread.c 8.2 (Berkeley) 12/11/93";
39 #else
40 __RCSID("$NetBSD: fread.c,v 1.22 2012/03/15 18:22:30 christos Exp $");
41 #endif
42 #endif /* LIBC_SCCS and not lint */
44 #include <assert.h>
45 #include <errno.h>
46 #include <stdio.h>
47 #include <string.h>
48 #include "reentrant.h"
49 #include "local.h"
51 size_t
52 fread(void *buf, size_t size, size_t count, FILE *fp)
54 size_t resid;
55 char *p;
56 int r;
57 size_t total;
59 _DIAGASSERT(fp != NULL);
61 * The ANSI standard requires a return value of 0 for a count
62 * or a size of 0. Whilst ANSI imposes no such requirements on
63 * fwrite, the SUSv2 does.
65 if ((resid = count * size) == 0)
66 return 0;
68 _DIAGASSERT(buf != NULL);
70 FLOCKFILE(fp);
71 if (fp->_r < 0)
72 fp->_r = 0;
73 total = resid;
74 p = buf;
75 while (resid > (size_t)(r = fp->_r)) {
76 (void)memcpy(p, fp->_p, (size_t)r);
77 fp->_p += r;
78 /* fp->_r = 0 ... done in __srefill */
79 p += r;
80 resid -= r;
81 if (__srefill(fp)) {
82 /* no more input: return partial result */
83 FUNLOCKFILE(fp);
84 return (total - resid) / size;
87 (void)memcpy(p, fp->_p, resid);
89 _DIAGASSERT(__type_fit(int, fp->_r - resid));
90 fp->_r -= (int)resid;
91 fp->_p += resid;
92 FUNLOCKFILE(fp);
93 return count;