1 files changed, 84 insertions, 0 deletions
diff --git a/tdekbdledsync/getfd.c b/tdekbdledsync/getfd.c
new file mode 100644
index 000000000..589d8dd31
--- /dev/null
+++ b/tdekbdledsync/getfd.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <linux/kd.h>
+#include "getfd.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;
+
+	arg = 0;
+	return (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 && errno == EACCES)
+		fd = open(fnam, O_WRONLY);
+	if (fd < 0 && errno == EACCES)
+		fd = open(fnam, O_RDONLY);
+	if (fd < 0)
+		return -1;
+	if (!is_a_console(fd)) {
+		close(fd);
+		return -1;
+	}
+	return fd;
+}
+
+int getfd(const char *fnam) {
+	int fd;
+
+	if (fnam) {
+		fd = open_a_console(fnam);
+		if (fd >= 0)
+			return fd;
+		fprintf(stderr,
+			("Couldnt open %s\n"), fnam);
+		exit(1);
+	}
+
+	fd = open_a_console("/dev/tty");
+	if (fd >= 0)
+		return fd;
+
+	fd = open_a_console("/dev/tty0");
+	if (fd >= 0)
+		return fd;
+
+	fd = open_a_console("/dev/vc/0");
+	if (fd >= 0)
+		return fd;
+
+	fd = open_a_console("/dev/console");
+	if (fd >= 0)
+		return fd;
+
+	for (fd = 0; fd < 3; fd++)
+		if (is_a_console(fd))
+			return fd;
+
+	fprintf(stderr,
+		("Couldnt get a file descriptor referring to the console\n"));
+	exit(1);		/* total failure */
+}