mirror of
https://github.com/sheumann/hush.git
synced 2024-12-28 07:30:23 +00:00
78 lines
1.5 KiB
C
78 lines
1.5 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Utility routines.
|
|
*
|
|
* Copyright (C) many different people. If you wrote this, please
|
|
* acknowledge your work.
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <sys/ioctl.h>
|
|
#include "libbb.h"
|
|
|
|
|
|
|
|
/* From <linux/kd.h> */
|
|
enum { KDGKBTYPE = 0x4B33 }; /* get keyboard type */
|
|
|
|
|
|
static int open_a_console(const char *fnam)
|
|
{
|
|
int fd;
|
|
|
|
/* try read-write */
|
|
fd = open(fnam, O_RDWR);
|
|
|
|
/* if failed, try read-only */
|
|
if (fd < 0 && errno == EACCES)
|
|
fd = open(fnam, O_RDONLY);
|
|
|
|
/* if failed, try write-only */
|
|
if (fd < 0 && errno == EACCES)
|
|
fd = open(fnam, O_WRONLY);
|
|
|
|
return fd;
|
|
}
|
|
|
|
/*
|
|
* Get an fd for use with kbd/console ioctls.
|
|
* We try several things because opening /dev/console will fail
|
|
* if someone else used X (which does a chown on /dev/console).
|
|
*/
|
|
|
|
int get_console_fd(void)
|
|
{
|
|
int fd;
|
|
|
|
static const char * const choise_console_names[] = {
|
|
CONSOLE_DEV, CURRENT_VC, CURRENT_TTY
|
|
};
|
|
|
|
for (fd = 2; fd >= 0; fd--) {
|
|
int fd4name;
|
|
int choise_fd;
|
|
char arg;
|
|
|
|
fd4name = open_a_console(choise_console_names[fd]);
|
|
chk_std:
|
|
choise_fd = (fd4name >= 0 ? fd4name : fd);
|
|
|
|
arg = 0;
|
|
if (ioctl(choise_fd, KDGKBTYPE, &arg) == 0)
|
|
return choise_fd;
|
|
if(fd4name >= 0) {
|
|
close(fd4name);
|
|
fd4name = -1;
|
|
goto chk_std;
|
|
}
|
|
}
|
|
|
|
bb_error_msg("cannot get file descriptor referring to console");
|
|
return fd; /* total failure */
|
|
}
|