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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <linux/kd.h>
#include "nls.h"
#include "getfd.h"
static char *conspath[] = {
"/proc/self/fd/0",
"/dev/tty",
"/dev/tty0",
"/dev/vc/0",
"/dev/systty",
"/dev/console",
NULL
};
/*
* 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;
arg = 0;
return (isatty (fd)
&& ioctl(fd, KDGKBTYPE, &arg) == 0
&& ((arg == KB_101) || (arg == KB_84)));
}
static int
open_a_console(const char *fnam) {
int fd;
/*
* For ioctl purposes we only need some fd and permissions
* do not matter. But setfont:activatemap() does a write.
*/
fd = open(fnam, O_RDWR);
if (fd < 0)
fd = open(fnam, O_WRONLY);
if (fd < 0)
fd = open(fnam, O_RDONLY);
if (fd < 0)
return -1;
return fd;
}
int
getfd(const char *fnam) {
int fd, i;
if (fnam) {
if ((fd = open_a_console(fnam)) >= 0) {
if (is_a_console(fd))
return fd;
close(fd);
}
fprintf(stderr, _("Couldn't open %s\n"), fnam);
exit(1);
}
for (i = 0; conspath[i]; i++) {
if ((fd = open_a_console(conspath[i])) >= 0) {
if (is_a_console(fd))
return fd;
close(fd);
}
}
for (fd = 0; fd < 3; fd++)
if (is_a_console(fd))
return fd;
fprintf(stderr,
_("Couldn't get a file descriptor referring to the console\n"));
/* total failure */
exit(1);
}
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