Add option -S to have dump(8) only estimate backup size and number of tapes

required (from NetBSD).

ok beck@, krw@ and sthen@

2 files changed, 19 insertions, 5 deletions

diff --git a/sbin/dump/dump.8 b/sbin/dump/dump.8
index 59f442d4a2b..e5e0dd7c7de 100644
--- a/sbin/dump/dump.8
+++ b/sbin/dump/dump.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: dump.8,v 1.45 2013/04/04 10:47:21 zhuk Exp $
+.\"	$OpenBSD: dump.8,v 1.46 2014/05/30 20:48:21 stephan Exp $
 .\"	$NetBSD: dump.8,v 1.17 1997/06/05 11:15:06 lukem Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
@@ -31,7 +31,7 @@
 .\"
 .\"     @(#)dump.8	8.1 (Berkeley) 6/16/93
 .\"
-.Dd $Mdocdate: April 4 2013 $
+.Dd $Mdocdate: May 30 2014 $
 .Dt DUMP 8
 .Os
 .Sh NAME
@@ -40,7 +40,7 @@
 .Sh SYNOPSIS
 .Nm dump
 .Bk -words
-.Op Fl 0123456789acnuWw
+.Op Fl 0123456789acnSuWw
 .Op Fl B Ar records
 .Op Fl b Ar blocksize
 .Op Fl d Ar density
@@ -203,6 +203,9 @@ notify all operators in the group
 .Dq operator
 by means similar to a
 .Xr wall 1 .
+.It Fl S
+Display an estimate of the backup size and the number of tapes
+required, and exit without actually performing the dump.
 .It Fl s Ar feet
 Attempt to calculate the amount of tape needed
 at a particular density.
diff --git a/sbin/dump/main.c b/sbin/dump/main.c
index f81d0a3d1f7..a5cd99e4821 100644
--- a/sbin/dump/main.c
+++ b/sbin/dump/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.48 2014/05/27 12:35:40 krw Exp $	*/
+/*	$OpenBSD: main.c,v 1.49 2014/05/30 20:48:21 stephan Exp $	*/
 /*	$NetBSD: main.c,v 1.14 1997/06/05 11:13:24 lukem Exp $	*/
 
 /*-
@@ -95,6 +95,7 @@ main(int argc, char *argv[])
 	time_t t;
 	int dirlist;
 	char *toplevel, *str, *mount_point = NULL;
+	int just_estimate = 0;
 
 	spcl.c_date = (int64_t)time(NULL);
 
@@ -111,7 +112,7 @@ main(int argc, char *argv[])
 		usage();
 
 	obsolete(&argc, &argv);
-	while ((ch = getopt(argc, argv, "0123456789aB:b:cd:f:h:ns:T:uWw")) != -1)
+	while ((ch = getopt(argc, argv, "0123456789aB:b:cd:f:h:ns:ST:uWw")) != -1)
 		switch (ch) {
 		/* dump level */
 		case '0': case '1': case '2': case '3': case '4':
@@ -159,6 +160,10 @@ main(int argc, char *argv[])
 			tsize = numarg("tape size", 1L, 0L) * 12 * 10;
 			break;
 
+		case 'S':		/* estimate blocks and # of tapes */
+			just_estimate = 1;
+			break;
+
 		case 'T':		/* time of last dump */
 			str = strptime(optarg, "%a %b %e %H:%M:%S %Y", &then);
 			then.tm_isdst = -1;
@@ -477,6 +482,12 @@ main(int argc, char *argv[])
 	}
 
 	/*
+	 * Exit if user wants an estimate of blocks and # of tapes only.
+	 */
+	if (just_estimate)
+		exit(X_FINOK);
+
+	/*
 	 * Allocate tape buffer.
 	 */
 	if (!alloctape())