2 files changed, 28 insertions, 17 deletions

diff --git a/usr.bin/mesg/mesg.1 b/usr.bin/mesg/mesg.1
index 77a29a15a005..c9f6800a21eb 100644
--- a/usr.bin/mesg/mesg.1
+++ b/usr.bin/mesg/mesg.1
@@ -32,7 +32,7 @@
 .\"	@(#)mesg.1	8.1 (Berkeley) 6/6/93
 .\" $FreeBSD$
 .\"
-.Dd June 6, 1993
+.Dd May 5, 2002
 .Dt MESG 1
 .Os
 .Sh NAME
@@ -44,15 +44,17 @@
 .Sh DESCRIPTION
 The
 .Nm
-utility is invoked by a users to control write access others
-have to the terminal device associated with the standard error
-output.
+utility is invoked by a user to control write access others
+have to a terminal device.
 Write access is allowed by default, and programs such as
 .Xr talk 1
 and
 .Xr write 1
 may display messages on the terminal.
 .Pp
+The first terminal device in the sequence of devices associated with standard
+input, standard output and standard error is affected.
+.Pp
 Options available:
 .Bl -tag -width flag
 .It Cm n
@@ -63,8 +65,8 @@ Permits messages to be displayed.
 .Pp
 If no arguments are given,
 .Nm
-displays the present message status to the standard error output.
-.Pp
+displays the present message status to the standard output.
+.Sh DIAGNOSTICS
 The
 .Nm
 utility exits with one of the following values:
@@ -77,15 +79,22 @@ Messages are not allowed.
 .It Li ">1"
 An error has occurred.
 .El
-.Sh FILES
-.Bl -tag -width /dev/[pt]ty[pq]? -compact
-.It Pa /dev/[pt]ty[pq]?
-.El
+.Sh COMPATIBILITY
+Previous versions of the
+.Nm
+utility wrote the message status to the standard error output and
+affected the terminal attached to standard error without first trying the
+standard input or output devices.
 .Sh SEE ALSO
 .Xr biff 1 ,
 .Xr talk 1 ,
 .Xr wall 1 ,
 .Xr write 1
+.Sh STANDARDS
+The
+.Nm
+utility conforms to
+.St -p1003.1-2001 .
 .Sh HISTORY
 A
 .Nm
diff --git a/usr.bin/mesg/mesg.c b/usr.bin/mesg/mesg.c
index d80acb6c9ef6..dcd14c39e3af 100644
--- a/usr.bin/mesg/mesg.c
+++ b/usr.bin/mesg/mesg.c
@@ -79,28 +79,30 @@ main(argc, argv)
 	argc -= optind;
 	argv += optind;
 
-	if ((tty = ttyname(STDERR_FILENO)) == NULL)
-		err(1, "ttyname");
+	if ((tty = ttyname(STDIN_FILENO)) == NULL &&
+	    (tty = ttyname(STDOUT_FILENO)) == NULL &&
+	    (tty = ttyname(STDERR_FILENO)) == NULL)
+		err(2, "ttyname");
 	if (stat(tty, &sb) < 0)
-		err(1, "%s", tty);
+		err(2, "%s", tty);
 
 	if (*argv == NULL) {
 		if (sb.st_mode & S_IWGRP) {
-			(void)fprintf(stderr, "is y\n");
+			(void)puts("is y");
 			exit(0);
 		}
-		(void)fprintf(stderr, "is n\n");
+		(void)puts("is n");
 		exit(1);
 	}
 
 	switch (*argv[0]) {
 	case 'y':
 		if (chmod(tty, sb.st_mode | S_IWGRP) < 0)
-			err(1, "%s", tty);
+			err(2, "%s", tty);
 		exit(0);
 	case 'n':
 		if (chmod(tty, sb.st_mode & ~S_IWGRP) < 0)
-			err(1, "%s", tty);
+			err(2, "%s", tty);
 		exit(1);
 	}