diff options
Diffstat (limited to 'lib/libc/stdio/fread.c')
| -rw-r--r-- | lib/libc/stdio/fread.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/lib/libc/stdio/fread.c b/lib/libc/stdio/fread.c new file mode 100644 index 0000000..3edb84a --- /dev/null +++ b/lib/libc/stdio/fread.c @@ -0,0 +1,100 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Chris Torek. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)fread.c 8.2 (Berkeley) 12/11/93"; +#endif /* LIBC_SCCS and not lint */ +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "namespace.h" +#include <stdio.h> +#include <string.h> +#include "un-namespace.h" +#include "local.h" +#include "libc_private.h" + +/* + * MT-safe version + */ + +size_t +fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp) +{ + int ret; + + FLOCKFILE(fp); + ret = __fread(buf, size, count, fp); + FUNLOCKFILE(fp); + return (ret); +} + +size_t +__fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp) +{ + size_t resid; + char *p; + int r; + size_t total; + + /* + * The ANSI standard requires a return value of 0 for a count + * or a size of 0. Peculiarily, it imposes no such requirements + * on fwrite; it only requires fread to be broken. + */ + if ((resid = count * size) == 0) + return (0); + ORIENT(fp, -1); + if (fp->_r < 0) + fp->_r = 0; + total = resid; + p = buf; + while (resid > (r = fp->_r)) { + (void)memcpy((void *)p, (void *)fp->_p, (size_t)r); + fp->_p += r; + /* fp->_r = 0 ... done in __srefill */ + p += r; + resid -= r; + if (__srefill(fp)) { + /* no more input: return partial result */ + return ((total - resid) / size); + } + } + (void)memcpy((void *)p, (void *)fp->_p, resid); + fp->_r -= resid; + fp->_p += resid; + return (count); +} |
