summaryrefslogtreecommitdiffstats
path: root/askfirst.c
blob: 2f948f8b30a7117ed306015f15754043f8157858 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
/*
 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation
 *
 * 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.
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

static int redirect_output(const char *dev)
{
	pid_t p = setsid();
	int fd;

	chdir("/dev");
	fd = open(dev, O_RDWR);
	chdir("/");

	if (fd < 0)
		return -1;

	close(STDIN_FILENO);
	close(STDOUT_FILENO);
	close(STDERR_FILENO);

	dup2(fd, STDIN_FILENO);
	dup2(fd, STDOUT_FILENO);
	dup2(fd, STDERR_FILENO);
	tcsetpgrp(fd, p);
	close(fd);

	return 0;
}

int main(int argc, char **argv)
{
	if (redirect_output(argv[1]))
		fprintf(stderr, "%s: Failed to open %s\n", argv[0], argv[1]);

	printf("Please press Enter to activate this console.\n");
	while (getchar() != 0xA)
		;
	execvp(argv[2], &argv[2]);
	printf("%s: Failed to execute %s\n", argv[0], argv[2]);

	return -1;
}