From 40cf9012a15ea5ea1f020f0afbb0c9012659549f Mon Sep 17 00:00:00 2001
From: sobomax <sobomax@FreeBSD.org>
Date: Tue, 25 Oct 2011 01:47:33 +0000
Subject: [PATCH] Add new option -F to specify alternative location of the
 /etc/fstab file.

MFC after:	1 month
---
 sbin/swapon/swapon.8 | 22 ++++++++++++++++++++--
 sbin/swapon/swapon.c | 11 +++++++++--
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/sbin/swapon/swapon.8 b/sbin/swapon/swapon.8
index 40dba745c093..5602a9a5ff86 100644
--- a/sbin/swapon/swapon.8
+++ b/sbin/swapon/swapon.8
@@ -35,8 +35,14 @@
 .Nm swapon , swapoff , swapctl
 .Nd "specify devices for paging and swapping"
 .Sh SYNOPSIS
-.Nm swapon Fl aq | Ar
-.Nm swapoff Fl aq | Ar
+.Nm swapon
+.Oo Fl F Ar fstab
+.Oc
+.Fl aq | Ar
+.Nm swapoff
+.Oo Fl F Ar fstab
+.Oc
+.Fl aq | Ar
 .Nm swapctl
 .Op Fl AghklmsU
 .Oo
@@ -99,6 +105,18 @@ must move swapped pages out of the device being removed which could
 lead to high system loads for a period of time, depending on how
 much data has been swapped out to that device.
 .Pp
+Other options supported by both
+.Nm swapon
+and
+.Nm swapoff
+are as follows:
+.Bl -tag -width indent
+.It Fl F Ar fstab
+Specify the
+.Pa fstab
+file to use.
+.El
+.Pp
 The
 .Nm swapctl
 utility exists primarily for those familiar with other
diff --git a/sbin/swapon/swapon.c b/sbin/swapon/swapon.c
index e2cf8cafc0b4..5e85602aaf5c 100644
--- a/sbin/swapon/swapon.c
+++ b/sbin/swapon/swapon.c
@@ -70,6 +70,7 @@ main(int argc, char **argv)
 	int stat;
 	int ch, doall;
 	int sflag = 0, lflag = 0, hflag = 0, qflag = 0;
+	const char *etc_fstab;
 
 	if ((ptr = strrchr(argv[0], '/')) == NULL)
 		ptr = argv[0];
@@ -80,7 +81,8 @@ main(int argc, char **argv)
 	orig_prog = which_prog;
 	
 	doall = 0;
-	while ((ch = getopt(argc, argv, "AadghklmqsU")) != -1) {
+	etc_fstab = NULL;
+	while ((ch = getopt(argc, argv, "AadghklmqsUF:")) != -1) {
 		switch(ch) {
 		case 'A':
 			if (which_prog == SWAPCTL) {
@@ -132,6 +134,9 @@ main(int argc, char **argv)
 				usage();
 			}
 			break;
+		case 'F':
+			etc_fstab = optarg;
+			break;
 		case '?':
 		default:
 			usage();
@@ -140,6 +145,8 @@ main(int argc, char **argv)
 	argv += optind;
 
 	stat = 0;
+	if (etc_fstab != NULL)
+		setfstab(etc_fstab);
 	if (which_prog == SWAPON || which_prog == SWAPOFF) {
 		if (doall) {
 			while ((fsp = getfsent()) != NULL) {
@@ -210,7 +217,7 @@ usage(void)
 	switch(orig_prog) {
 	case SWAPON:
 	case SWAPOFF:
-	    fprintf(stderr, "-aq | file ...\n");
+	    fprintf(stderr, "[-F fstab] -aq | file ...\n");
 	    break;
 	case SWAPCTL:
 	    fprintf(stderr, "[-AghklmsU] [-a file ... | -d file ...]\n");