Add 'corebinutils/sync/' from commit 'a304c2b9dd922485b980b94fe635b512d9dce9c2'

git-subtree-dir: corebinutils/sync
git-subtree-mainline: 1edb2cb7b8a720ba8ae4438947256515a93b7ca9
git-subtree-split: a304c2b9dd922485b980b94fe635b512d9dce9c2

1 files changed, 85 insertions, 0 deletions

diff --git a/corebinutils/sync/sync.c b/corebinutils/sync/sync.c
new file mode 100644
index 0000000000..c1ff6f783b
--- /dev/null
+++ b/corebinutils/sync/sync.c
@@ -0,0 +1,85 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1987, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Copyright (c) 2026
+ *	Project Tick. All rights reserved.
+ *
+ * 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.
+ */
+
+#define _POSIX_C_SOURCE 200809L
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/*
+ * Linux libcs commonly hide sync(2) behind non-POSIX feature macros.
+ * Declare the documented interface explicitly so the port stays buildable
+ * under strict C/POSIX settings without enabling GNU extensions.
+ */
+extern void sync(void);
+
+static const char *progname = "sync";
+
+static void	usage_error(const char *fmt, ...)
+    __attribute__((format(printf, 1, 2), noreturn));
+
+int
+main(int argc, char *argv[])
+{
+	const char *slash;
+
+	if (argv[0] != NULL && argv[0][0] != '\0') {
+		slash = strrchr(argv[0], '/');
+		progname = (slash != NULL && slash[1] != '\0') ? slash + 1 : argv[0];
+	}
+
+	if (argc > 1)
+		usage_error("unexpected argument: %s", argv[1]);
+
+	sync();
+	return (0);
+}
+
+static void
+usage_error(const char *fmt, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, "%s: ", progname);
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+
+	fprintf(stderr, "\nusage: %s\n", progname);
+	exit(1);
+}