1 files changed, 63 insertions, 0 deletions
diff --git a/util-linux/wall.c b/util-linux/wall.c
new file mode 100644
index 000000000..50658f457
--- /dev/null
+++ b/util-linux/wall.c
@@ -0,0 +1,63 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * wall - write a message to all logged-in users
+ * Copyright (c) 2009 Bernhard Reutner-Fischer
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+//config:config WALL
+//config:	bool "wall"
+//config:	default y
+//config:	depends on FEATURE_UTMP
+//config:	help
+//config:	  Write a message to all users that are logged in.
+
+/* Needs to be run by root or be suid root - needs to write to /dev/TTY: */
+//applet:IF_WALL(APPLET(wall, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
+
+//kbuild:lib-$(CONFIG_WALL) += wall.o
+
+//usage:#define wall_trivial_usage
+//usage:	"[FILE]"
+//usage:#define wall_full_usage "\n\n"
+//usage:	"Write content of FILE or stdin to all logged-in users"
+//usage:
+//usage:#define wall_sample_usage
+//usage:	"echo foo | wall\n"
+//usage:	"wall ./mymessage"
+
+#include "libbb.h"
+
+int wall_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int wall_main(int argc UNUSED_PARAM, char **argv)
+{
+	struct utmpx *ut;
+	char *msg;
+	int fd;
+
+	fd = STDIN_FILENO;
+	if (argv[1]) {
+		/* The applet is setuid.
+		 * Access to the file must be under user's uid/gid.
+		 */
+		fd = xopen_as_uid_gid(argv[1], O_RDONLY, getuid(), getgid());
+	}
+	msg = xmalloc_read(fd, NULL);
+	if (ENABLE_FEATURE_CLEAN_UP && argv[1])
+		close(fd);
+	setutxent();
+	while ((ut = getutxent()) != NULL) {
+		char *line;
+		if (ut->ut_type != USER_PROCESS)
+			continue;
+		line = concat_path_file("/dev", ut->ut_line);
+		xopen_xwrite_close(line, msg);
+		free(line);
+	}
+	if (ENABLE_FEATURE_CLEAN_UP) {
+		endutxent();
+		free(msg);
+	}
+	return EXIT_SUCCESS;
+}