1 files changed, 99 insertions, 0 deletions

diff --git a/busybox/libbb/get_console.c b/busybox/libbb/get_console.c
new file mode 100644
index 000000000..bfb7468a8
--- /dev/null
+++ b/busybox/libbb/get_console.c
@@ -0,0 +1,99 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) many different people.  If you wrote this, please
+ * acknowledge your work.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include "libbb.h"
+
+
+
+/* From <linux/kd.h> */
+static const int 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("Couldn't get a file descriptor referring to the console");
+        return fd;                      /* total failure */
+}
+
+
+/* END CODE */
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/