Signal init(8) instead of executing halt(8) or reboot(8)

when halting or rebooting the system.  It benefits from
running /etc/rc.shutdown by init(8).

``-o'' flag is provided for backward compatibility.

PR:		5451
Discussed with:	des

2 files changed, 100 insertions, 70 deletions

diff --git a/sbin/shutdown/shutdown.8 b/sbin/shutdown/shutdown.8
index 90041f5..876c287 100644
--- a/sbin/shutdown/shutdown.8
+++ b/sbin/shutdown/shutdown.8
@@ -30,7 +30,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     @(#)shutdown.8	8.2 (Berkeley) 4/27/95
-.\"	$Id: shutdown.8,v 1.9 1999/01/11 09:07:42 asami Exp $
+.\"	$Id: shutdown.8,v 1.10 1999/06/21 06:21:04 jkoshy Exp $
 .\"
 .Dd Dec 11, 1998
 .Dt SHUTDOWN 8
@@ -40,8 +40,15 @@
 .Nd "close down the system at a given time"
 .Sh SYNOPSIS
 .Nm shutdown
-.Op Fl 
-.Op Fl hknpr
+.Op Fl
+.Oo
+.Fl h | Fl p |
+.Fl r | Fl k
+.Oc
+.Oo
+.Fl o
+.Op Fl n
+.Oc
 .Ar time
 .Op Ar warning-message ...
 .Sh DESCRIPTION
@@ -55,11 +62,15 @@ The following options are available:
 .Bl -tag -width indent
 .It Fl h
 The system is halted at the specified
-.Ar time
-when
-.Nm
-executes
-.Xr halt 8 .
+.Ar time .
+.It Fl p
+The system is halted and the power is turned off
+.Pq hardware support required
+at the specified
+.Ar time .
+.It Fl r
+The system is rebooted at the specified
+.Ar time .
 .It Fl k
 Kick everybody off.
 The
@@ -67,21 +78,30 @@ The
 option
 does not actually halt the system, but leaves the
 system multi-user with logins disabled (for all but super-user).
-.It Fl n
-Prevent the normal
-.Xr sync 2
-before stopping.
-This option is ignored if
-.Fl k
-is specified.
-.It Fl p
-The system will turn the power off after shutdown if it can.
-.It Fl r 
-.Nm Shutdown
-executes
+.It Fl o
+If one of the
+.Fl h ,
+.Fl p
+or
+.Fl r
+is specified,
+.Nm
+will execute
+.Xr halt 8
+or
 .Xr reboot 8
-at the specified
-.Ar time .
+instead of sending signal to
+.Xr init 8 .
+.It Fl n
+If the
+.Fl o
+is specified, prevent the file system cache from being flushed by passing
+.Fl n
+option to
+.Xr halt 8
+or
+.Xr reboot 8 .
+This option should probably not be used.
 .It Ar time
 .Ar Time
 is the time at which
@@ -108,14 +128,6 @@ is supplied as an option, the warning message is read from the standard
 input.
 .El
 .Pp
-Only one of 
-.Fl h ,
-.Fl k ,
-.Fl p ,
-and
-.Fl r
-can be specified at a time.
-.Pp
 At intervals, becoming more frequent as apocalypse approaches
 and starting at ten hours before shutdown, warning messages are displayed
 on the terminals of all users logged in.  Five minutes before
@@ -131,13 +143,12 @@ removed just before
 .Nm
 exits.
 .Pp
-At shutdown time a message is written in the system log, containing the
-time of shutdown, who initiated the shutdown and the reason.
-A terminate
-signal is then sent to
+At shutdown time a message is written to the system log, containing the
+time of shutdown, the person who initiated the shutdown and the reason.
+Corresponding signal is then sent to
 .Xr init 8
-to bring the system down to single-user state (depending on above
-options).
+to respectively halt, reboot or bring the system down to single-user state
+(depending on the above options).
 The time of the shutdown and the warning message
 are placed in
 .Pa /var/run/nologin
@@ -154,6 +165,7 @@ tells login not to let anyone log in
 .Xr wall 1 ,
 .Xr nologin 5 ,
 .Xr halt 8 ,
+.Xr init 8 ,
 .Xr reboot 8
 .Sh BACKWARD COMPATIBILITY
 The hours and minutes in the second time format may be separated by
diff --git a/sbin/shutdown/shutdown.c b/sbin/shutdown/shutdown.c
index 8f9e7c8..e81711a 100644
--- a/sbin/shutdown/shutdown.c
+++ b/sbin/shutdown/shutdown.c
@@ -42,7 +42,7 @@ static const char copyright[] =
 static char sccsid[] = "@(#)shutdown.c	8.4 (Berkeley) 4/28/95";
 #endif
 static const char rcsid[] =
-	"$Id: shutdown.c,v 1.17 1999/06/18 14:26:07 ru Exp $";
+	"$Id: shutdown.c,v 1.18 1999/06/21 06:21:05 jkoshy Exp $";
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -93,7 +93,7 @@ struct interval {
 #undef S
 
 static time_t offset, shuttime;
-static int dohalt, dopower, doreboot, killflg, mbuflen;
+static int dohalt, dopower, doreboot, killflg, mbuflen, oflag;
 static char *nosync, *whom, mbuf[BUFSIZ];
 
 void badtime __P((void));
@@ -104,7 +104,7 @@ void loop __P((void));
 void nolog __P((void));
 void timeout __P((int));
 void timewarn __P((int));
-void usage __P((void));
+void usage __P((const char *));
 
 int
 main(argc, argv)
@@ -121,7 +121,7 @@ main(argc, argv)
 #endif
 	nosync = NULL;
 	readstdin = 0;
-	while ((ch = getopt(argc, argv, "-hknpr")) != -1)
+	while ((ch = getopt(argc, argv, "-hknopr")) != -1)
 		switch (ch) {
 		case '-':
 			readstdin = 1;
@@ -135,6 +135,9 @@ main(argc, argv)
 		case 'n':
 			nosync = "-n";
 			break;
+		case 'o':
+			oflag = 1;
+			break;
 		case 'p':
 			dopower = 1;
 			break;
@@ -143,21 +146,22 @@ main(argc, argv)
 			break;
 		case '?':
 		default:
-			usage();
+			usage((char *)NULL);
 		}
 	argc -= optind;
 	argv += optind;
 
 	if (argc < 1)
-		usage();
+		usage((char *)NULL);
 
-	if (killflg + doreboot + dohalt + dopower > 1) {
-		warnx("incompatible switches -h, -k, -p and -r");
-		usage();
-	}
+	if (killflg + doreboot + dohalt + dopower > 1)
+		usage("incompatible switches -h, -k, -p and -r");
 
-	if (killflg && nosync)
-		warnx("option -n ignored with -k");
+	if (oflag && !(dohalt || dopower || doreboot))
+		usage("-o requires -h, -p or -r");
+
+	if (nosync != NULL && !oflag)
+		usage("-n requires -o");
 
 	getoffset(*argv++);
 
@@ -349,29 +353,39 @@ die_you_gravy_sucking_pig_dog()
 		(void)printf("halt");
 	else if (dopower)
 		(void)printf("power-down");
-	if (nosync)
+	if (nosync != NULL)
 		(void)printf(" no sync");
 	(void)printf("\nkill -HUP 1\n");
 #else
-	if (doreboot) {
-		execle(_PATH_REBOOT, "reboot", "-l", nosync, 
-			   (char *)NULL, empty_environ);
-		syslog(LOG_ERR, "shutdown: can't exec %s: %m.", _PATH_REBOOT);
-		warn(_PATH_REBOOT);
-	}
-	else if (dohalt) {
-		execle(_PATH_HALT, "halt", "-l", nosync,
-			   (char *)NULL, empty_environ);
-		syslog(LOG_ERR, "shutdown: can't exec %s: %m.", _PATH_HALT);
-		warn(_PATH_HALT);
-	}
-	else if (dopower) {
-		execle(_PATH_HALT, "halt", "-l", "-p", nosync,
-			   (char *)NULL, empty_environ);
-		syslog(LOG_ERR, "shutdown: can't exec %s: %m.", _PATH_HALT);
-		warn(_PATH_HALT);
+	if (!oflag) {
+		(void)kill(1, doreboot ? SIGINT :	/* reboot */
+			      dohalt ? SIGUSR1 :	/* halt */
+			      dopower ? SIGUSR2 :	/* power-down */
+			      SIGTERM);			/* single-user */
+	} else {
+		if (doreboot) {
+			execle(_PATH_REBOOT, "reboot", "-l", nosync, 
+				(char *)NULL, empty_environ);
+			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
+				_PATH_REBOOT);
+			warn(_PATH_REBOOT);
+		}
+		else if (dohalt) {
+			execle(_PATH_HALT, "halt", "-l", nosync,
+				(char *)NULL, empty_environ);
+			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
+				_PATH_HALT);
+			warn(_PATH_HALT);
+		}
+		else if (dopower) {
+			execle(_PATH_HALT, "halt", "-l", "-p", nosync,
+				(char *)NULL, empty_environ);
+			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
+				_PATH_HALT);
+			warn(_PATH_HALT);
+		}
+		(void)kill(1, SIGTERM);		/* to single-user */
 	}
-	(void)kill(1, SIGTERM);		/* to single user */
 #endif
 	finish(0);
 }
@@ -499,9 +513,13 @@ badtime()
 }
 
 void
-usage()
+usage(cp)
+	const char *cp;
 {
-	fprintf(stderr,
-	    "usage: shutdown [-] [-hknpr] time [warning-message ...]\n");
+	if (cp != NULL)
+		warnx("%s", cp);
+	(void)fprintf(stderr,
+	    "usage: shutdown [-] [-h | -p | -r | -k] [-o [-n]]"
+	    " time [warning-message ...]\n");
 	exit(1);
 }