1 files changed, 10 insertions, 5 deletions

diff --git a/mt.c b/mt.c
index 9791b64b2..cf20d1711 100644
--- a/mt.c
+++ b/mt.c
@@ -4,7 +4,8 @@
 #include <sys/mtio.h>
 #include <sys/fcntl.h>
 
-static const char mt_usage[] = "mt [-f device] opcode value\n";
+static const char mt_usage[] = "mt [-f device] opcode value\n\n"
+                        "Control magnetic tape drive operation\n";
 
 struct mt_opcodes {
         char *name;
@@ -56,6 +57,10 @@ extern int mt_main(int argc, char **argv)
         const struct mt_opcodes *code = opcodes;
         struct mtop op;
         int fd;
+        
+        if ((argc != 2 && argc != 3) || **(argv + 1) == '-') {
+                usage(mt_usage);
+        }
 
         if (strcmp(argv[1], "-f") == 0) {
                 if (argc < 4) {
@@ -74,7 +79,7 @@ extern int mt_main(int argc, char **argv)
 
         if (code->name == 0) {
                 fprintf(stderr, "mt: unrecognized opcode %s.\n", argv[1]);
-                return (FALSE);
+                exit (FALSE);
         }
 
         op.mt_op = code->value;
@@ -85,13 +90,13 @@ extern int mt_main(int argc, char **argv)
 
         if ((fd = open(file, O_RDONLY, 0)) < 0) {
                 perror(file);
-                return (FALSE);
+                exit (FALSE);
         }
 
         if (ioctl(fd, MTIOCTOP, &op) != 0) {
                 perror(file);
-                return (FALSE);
+                exit (FALSE);
         }
 
-        return (TRUE);
+        exit (TRUE);
 }