Before terminal characteristics are displayed, stty(1) activates

pledge(2).  Then the values cannot be modified anymore.  Let stty
error out if the display and modify mode are combined on the command
line to avoid a pledge violation later on.
OK deraadt@

diff --git a/bin/stty/stty.c b/bin/stty/stty.c
index 7de9b8f..4d70ae6 100644 (file)
--- a/bin/stty/stty.c
+++ b/bin/stty/stty.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: stty.c,v 1.19 2016/03/23 14:52:42 mmcc Exp $  */
+/*     $OpenBSD: stty.c,v 1.20 2016/07/23 08:57:18 bluhm Exp $ */
 /*     $NetBSD: stty.c,v 1.11 1995/03/21 09:11:30 cgd Exp $    */
 
 /*-
@@ -97,11 +97,15 @@ args:       argc -= optind;
                /* FALLTHROUGH */
        case BSD:
        case POSIX:
+               if (*argv)
+                       errx(1, "either display or modify");
                if (pledge("stdio", NULL) == -1)
                        err(1, "pledge");
                print(&i.t, &i.win, i.ldisc, fmt);
                break;
        case GFLAG:
+               if (*argv)
+                       errx(1, "either display or modify");
                if (pledge("stdio", NULL) == -1)
                        err(1, "pledge");
                gprint(&i.t, &i.win, i.ldisc);