[BusyBox] Problem with 'mt' ?

[Matt Kraai]

On Mon, May 21, 2001 at 01:37:54PM +0000, Tom Oehser wrote:
> There is something wrong with 'mt' which causes it to give incorrect
> 'permission denied' errors, which do not happen with the gnu or bsd
> versions of the command...

Could you please test the following patch and let me know if it
fixes your problem?  If so, I'll commit it.

Matt

Index: mt.c
===================================================================
RCS file: /var/cvs/busybox/mt.c,v
retrieving revision 1.20
diff -u -r1.20 mt.c
--- mt.c	2001/03/09 14:36:42	1.20
+++ mt.c	2001/05/21 14:26:02
@@ -55,7 +55,7 @@
 	const char *file = "/dev/tape";
 	const struct mt_opcodes *code = opcodes;
 	struct mtop op;
-	int fd;
+	int fd, mode;
 	
 	if (argc < 2) {
 		show_usage();
@@ -87,7 +87,20 @@
 	else
 		op.mt_count = 1;		/* One, not zero, right? */
 
-	if ((fd = open(file, O_RDONLY, 0)) < 0)
+	switch (code->value) {
+		case MTWEOF:
+		case MTERASE:
+		case MTWSM:
+		case MTSETDRVBUFFER:
+			mode = O_WRONLY;
+			break;
+
+		default:
+			mode = O_RDONLY;
+			break;
+	}
+
+	if ((fd = open(file, mode, 0)) < 0)
 		perror_msg_and_die("%s", file);
 
 	if (ioctl(fd, MTIOCTOP, &op) != 0)