mesg applet by Manuel Novoa III

include/applets.h

@@ -293,6 +293,9 @@
 #ifdef CONFIG_MD5SUM
 	APPLET(md5sum, md5sum_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_MESG
+	APPLET(mesg, mesg_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_MKDIR
 	APPLET(mkdir, mkdir_main, _BB_DIR_BIN, _BB_SUID_NEVER)
 #endif

include/usage.h

@@ -1149,6 +1149,13 @@
 	"busybox: OK\n" \
 	"^D\n"
 
+#define mesg_trivial_usage \
+	"mesg [y|n]"
+#define mesg_full_usage \
+	"mesg [Y|N], controls write access to your terminal\n" \
+	"\ty\tAllow write access to your terminal.\n" \
+	"\tn\tDisallow write access to your terminal.\n"
+
 #define mkdir_trivial_usage \
 	"[OPTION] DIRECTORY..."
 #define mkdir_full_usage \

init/Makefile.in

@@ -25,6 +25,7 @@ endif
 INIT-y:=
 INIT-$(CONFIG_HALT)			+= halt.o
 INIT-$(CONFIG_INIT)			+= init.o
+INIT-$(CONFIG_MESG)			+= mesg.o
 INIT-$(CONFIG_POWEROFF)			+= poweroff.o
 INIT-$(CONFIG_REBOOT)			+= reboot.o
 INIT-$(CONFIG_START_STOP_DAEMON)	+= start_stop_daemon.o

init/config.in

@@ -22,6 +22,7 @@ fi
 
 bool 'start-stop-daemon'	    CONFIG_START_STOP_DAEMON
 bool 'run-parts'		    CONFIG_RUN_PARTS
+bool 'mesg'			    CONFIG_MESG
 	
 endmenu
 

init/mesg.c

@@ -0,0 +1,58 @@
+/*
+ *  mesg implementation for busybox
+ *
+ *  Copyright (c) 2002 Manuel Novoa III  <mjn3@codepoet.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include "libbb.h"
+
+#ifdef USE_TTY_GROUP
+#define S_IWGRP_OR_S_IWOTH	S_IWGRP
+#else
+#define S_IWGRP_OR_S_IWOTH	(S_IWGRP | S_IWOTH)
+#endif
+
+extern int mesg_main(int argc, char *argv[])
+{
+	struct stat sb;
+	char *tty;
+	char c;
+
+	if ((--argc == 0)
+		|| ((argc == 1) && (((c = **++argv) == 'y') || (c == 'n')))) {
+		if ((tty = ttyname(STDERR_FILENO)) == NULL) {
+			tty = "ttyname";
+		} else if (stat(tty, &sb) == 0) {
+			if (argc == 0) {
+				puts(((sb.st_mode & (S_IWGRP | S_IWOTH)) ==
+					  0) ? "is n" : "is y");
+				return EXIT_SUCCESS;
+			}
+			if (chmod
+				(tty,
+				 (c ==
+				  'y') ? sb.st_mode | (S_IWGRP_OR_S_IWOTH) : sb.
+				 st_mode & ~(S_IWGRP | S_IWOTH)) == 0) {
+				return EXIT_SUCCESS;
+			}
+		}
+		perror_msg_and_die("%s", tty);
+	}
+	show_usage();
+}