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/*
* Adapted from kbd-1.12
* License: GPL
*
*/
#include "config.h"
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#ifdef __linux__
#include <linux/kd.h>
#endif
#include <sys/ioctl.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif /* HAVE_PATHS_H */
/*
* getfd.c
*
* 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).
*/
static int
is_a_console (int fd)
{
char arg;
int kb_ok;
arg = 0;
#ifdef __linux__
kb_ok = (ioctl (fd, KDGKBTYPE, &arg) == 0
&& ((arg == KB_101) || (arg == KB_84)));
#else
kb_ok = 1;
#endif
return (isatty (fd) && kb_ok);
}
static int
open_a_console (char *fnam)
{
int fd;
fd = open (fnam, O_RDONLY | O_NOCTTY);
if (fd < 0 && errno == EACCES)
fd = open (fnam, O_WRONLY | O_NOCTTY);
if (fd < 0)
return -1;
if (! is_a_console (fd)) {
close (fd);
fd = -1;
}
return fd;
}
int getfd (void)
{
int fd;
#ifdef _PATH_TTY
fd = open_a_console (_PATH_TTY);
if (fd >= 0)
return fd;
#endif
fd = open_a_console ("/dev/tty");
if (fd >= 0)
return fd;
#ifdef _PATH_CONSOLE
fd = open_a_console (_PATH_CONSOLE);
if (fd >= 0)
return fd;
#endif
fd = open_a_console ("/dev/console");
if (fd >= 0)
return fd;
for (fd = 0; fd < 3; fd++)
if (is_a_console (fd))
return fd;
return -1;
}
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