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/* 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 utmp *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.
*/
setfsuid(getuid());
setfsgid(getgid());
fd = xopen(argv[1], O_RDONLY);
setfsuid(geteuid());
setfsgid(getegid());
}
msg = xmalloc_read(fd, NULL);
if (ENABLE_FEATURE_CLEAN_UP && argv[1])
close(fd);
setutent();
while ((ut = getutent()) != 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) {
endutent();
free(msg);
}
return EXIT_SUCCESS;
}
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