1 files changed, 96 insertions, 0 deletions
diff --git a/lib/libc/stdio/fwrite.c b/lib/libc/stdio/fwrite.c
new file mode 100644
index 0000000..707d362
--- /dev/null
+++ b/lib/libc/stdio/fwrite.c
@@ -0,0 +1,96 @@
+/*-
+ * 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. 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[] = "@(#)fwrite.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include "un-namespace.h"
+#include "local.h"
+#include "fvwrite.h"
+#include "libc_private.h"
+
+/*
+ * Write `count' objects (each size `size') from memory to the given file.
+ * Return the number of whole objects written.
+ */
+size_t
+fwrite(const void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
+{
+	size_t n;
+	struct __suio uio;
+	struct __siov iov;
+
+	/*
+	 * ANSI and SUSv2 require a return value of 0 if size or count are 0.
+	 */
+	if ((count == 0) || (size == 0))
+		return (0);
+
+	/*
+	 * Check for integer overflow.  As an optimization, first check that
+	 * at least one of {count, size} is at least 2^16, since if both
+	 * values are less than that, their product can't possible overflow
+	 * (size_t is always at least 32 bits on FreeBSD).
+	 */
+	if (((count | size) > 0xFFFF) &&
+	    (count > SIZE_MAX / size)) {
+		errno = EINVAL;
+		fp->_flags |= __SERR;
+		return (0);
+	}
+
+	n = count * size;
+
+	iov.iov_base = (void *)buf;
+	uio.uio_resid = iov.iov_len = n;
+	uio.uio_iov = &iov;
+	uio.uio_iovcnt = 1;
+
+	FLOCKFILE(fp);
+	ORIENT(fp, -1);
+	/*
+	 * The usual case is success (__sfvwrite returns 0);
+	 * skip the divide if this happens, since divides are
+	 * generally slow and since this occurs whenever size==0.
+	 */
+	if (__sfvwrite(fp, &uio) != 0)
+	    count = (n - uio.uio_resid) / size;
+	FUNLOCKFILE(fp);
+	return (count);
+}