From aad1a88c76f208d188fd061e3723bd637437e8d5 Mon Sep 17 00:00:00 2001
From: Eric Andersen <andersen@codepoet.org>
Date: Fri, 16 Mar 2001 22:47:14 +0000
Subject: Convert utility.c into libbb.a.  It is now a whole pile of .c files. 
 Clean up the resulting damage and fix up the makefile.  -Erik

---
 libbb/get_console.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 libbb/get_console.c

(limited to 'libbb/get_console.c')

diff --git a/libbb/get_console.c b/libbb/get_console.c
new file mode 100644
index 000000000..4be9adc84
--- /dev/null
+++ b/libbb/get_console.c
@@ -0,0 +1,129 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) tons of folks.  Tracking down who wrote what
+ * isn't something I'm going to worry about...  If you wrote something
+ * here, please feel free to 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
+ *
+ * Based in part on code from sash, Copyright (c) 1999 by David I. Bell 
+ * Permission has been granted to redistribute this code under the GPL.
+ *
+ */
+
+#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 const int KB_84 = 0x01;
+static const int KB_101 = 0x02;    /* this is what we always answer */
+
+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(char *fnam)
+{
+	int fd;
+
+	/* try read-only */
+	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);
+
+	/* if failed, fail */
+	if (fd < 0)
+		return -1;
+
+	/* if not a console, fail */
+	if (!is_a_console(fd)) {
+		close(fd);
+		return -1;
+	}
+
+	/* success */
+	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).
+ *
+ * if tty_name is non-NULL, try this one instead.
+ */
+
+int get_console_fd(char *tty_name)
+{
+	int fd;
+
+	if (tty_name) {
+		if (-1 == (fd = open_a_console(tty_name)))
+			return -1;
+		else
+			return fd;
+	}
+
+	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/console");
+	if (fd >= 0)
+		return fd;
+
+	for (fd = 0; fd < 3; fd++)
+		if (is_a_console(fd))
+			return fd;
+
+	error_msg("Couldnt get a file descriptor referring to the console");
+	return -1;					/* total failure */
+}
+
+
+/* END CODE */
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/
-- 
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