Implement the '-F' option for mount & umount which allows the user to

specify an alternate fstab file.

2 files changed, 18 insertions, 3 deletions

diff --git a/sbin/umount/umount.8 b/sbin/umount/umount.8
index 8d75508..bdaa34b 100644
--- a/sbin/umount/umount.8
+++ b/sbin/umount/umount.8
@@ -44,6 +44,7 @@
 .Ar special \&| node
 .Nm
 .Fl a | A
+.Op Fl F Ar fstab
 .Op Fl fv
 .Op Fl h Ar host
 .Op Fl t Ar type
@@ -73,6 +74,10 @@ are unmounted.
 .It Fl A
 All the currently mounted file systems except
 the root are unmounted.
+.It Fl F Ar fstab
+Specify the
+.Pa fstab
+file to use.
 .It Fl f
 The file system is forcibly unmounted.
 Active special devices continue to work,
@@ -115,6 +120,13 @@ file.
 Verbose, additional information is printed out as each file system
 is unmounted.
 .El
+.Sh ENVIRONMENT
+.Bl -tag -width PATH_FSTAB
+.It Pa PATH_FSTAB
+If the environment variable
+.Pa PATH_FSTAB
+is set all operations are performed against the specified file.
+.El
 .Sh FILES
 .Bl -tag -width /etc/fstab -compact
 .It Pa /etc/fstab
diff --git a/sbin/umount/umount.c b/sbin/umount/umount.c
index 3969860..8ffdbce 100644
--- a/sbin/umount/umount.c
+++ b/sbin/umount/umount.c
@@ -100,7 +100,7 @@ main(int argc, char *argv[])
 	sync();
 
 	all = errs = 0;
-	while ((ch = getopt(argc, argv, "Aafh:t:v")) != -1)
+	while ((ch = getopt(argc, argv, "AaF:fh:t:v")) != -1)
 		switch (ch) {
 		case 'A':
 			all = 2;
@@ -108,6 +108,9 @@ main(int argc, char *argv[])
 		case 'a':
 			all = 1;
 			break;
+		case 'F':
+			setfstab(optarg);
+			break;
 		case 'f':
 			fflag = MNT_FORCE;
 			break;
@@ -184,7 +187,7 @@ main(int argc, char *argv[])
 		break;
 	case 1:
 		if (setfsent() == 0)
-			err(1, "%s", _PATH_FSTAB);
+			err(1, "%s", getfstab());
 		errs = umountall(typelist);
 		break;
 	case 0:
@@ -751,6 +754,6 @@ usage()
 
 	(void)fprintf(stderr, "%s\n%s\n",
 	    "usage: umount [-fv] special | node",
-	    "       umount -a | -A [-fv] [-h host] [-t type]");
+	    "       umount -a | -A [ -F fstab] [-fv] [-h host] [-t type]");
 	exit(1);
 }