3 files changed, 155 insertions, 0 deletions
diff --git a/usr.sbin/update/Makefile b/usr.sbin/update/Makefile
new file mode 100644
index 000000000000..ea20d0566b2e
--- /dev/null
+++ b/usr.sbin/update/Makefile
@@ -0,0 +1,6 @@
+#	@(#)Makefile	8.1 (Berkeley) 6/6/93
+
+PROG=	update
+MAN8=	update.0
+
+.include <bsd.prog.mk>
diff --git a/usr.sbin/update/update.8 b/usr.sbin/update/update.8
new file mode 100644
index 000000000000..78665fafe71d
--- /dev/null
+++ b/usr.sbin/update/update.8
@@ -0,0 +1,74 @@
+.\" Copyright (c) 1991, 1993
+.\"	The Regents of the University of California.  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. 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.
+.\"
+.\"	@(#)update.8	8.3 (Berkeley) 4/19/94
+.\"
+.Dd April 19, 1994
+.Dt UPDATE 8
+.Os
+.Sh NAME
+.Nm update
+.Nd flush internal filesystem caches to disk frequently
+.Sh SYNOPSIS
+.Nm update
+.Sh DESCRIPTION
+The
+.Nm update
+command helps protect the integrity of disk volumes
+by flushing
+volatile cached filesystem data
+to disk at thirty second intervals.
+.Nm Update
+uses the
+.Xr sync 2
+function call to do the task.
+.Pp
+.Nm Update
+is commonly invoked at startup time by
+.Xr rc 8
+when the system goes multi-user.
+.Sh SEE ALSO
+.Xr sync 2 ,
+.Xr fsck 8 ,
+.Xr init 8 ,
+.Xr rc 8 ,
+.Xr sync 8
+.Sh BUGS
+It is possible on some systems that a
+.Xr sync
+occurring simultaneously with a crash may cause
+file system damage. See
+.Xr fsck 8 .
+.Sh HISTORY
+An
+.Nm update
+command appeared in
+.At v6 .
diff --git a/usr.sbin/update/update.c b/usr.sbin/update/update.c
new file mode 100644
index 000000000000..ae83ad10b08c
--- /dev/null
+++ b/usr.sbin/update/update.c
@@ -0,0 +1,75 @@
+/*-
+ * Copyright (c) 1987, 1990, 1993
+ *	The Regents of the University of California.  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. 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.
+ */
+
+#ifndef lint
+static char copyright[] =
+"@(#) Copyright (c) 1987, 1990, 1993\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+static char sccsid[] = "@(#)update.c	8.1 (Berkeley) 6/6/93";
+#endif /* not lint */
+
+#include <sys/time.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+main()
+{
+	struct itimerval value;
+	void mysync();
+
+	daemon(0, 0);
+
+	(void)signal(SIGALRM, mysync);
+
+	value.it_interval.tv_sec = 30;
+	value.it_interval.tv_usec = 0;
+	value.it_value = value.it_interval;
+	if (setitimer(ITIMER_REAL, &value, NULL)) {
+		perror("update: setitimer");
+		exit(1);
+	}
+	for (;;)
+		sigpause(sigblock(0L));
+	/* NOTREACHED */
+}
+
+void
+mysync()
+{
+	(void)sync();
+}