From fd6bb20116127f6ac903d4b03abac72a49baa1ae Mon Sep 17 00:00:00 2001
From: fishsoupisgood <github@madingley.org>
Date: Sat, 27 Apr 2019 22:20:21 +0100
Subject: fish

---
 vt.c | 196 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 196 insertions(+)
 create mode 100644 vt.c

(limited to 'vt.c')

diff --git a/vt.c b/vt.c
new file mode 100644
index 0000000..084a072
--- /dev/null
+++ b/vt.c
@@ -0,0 +1,196 @@
+/* 
+ * Copyright 1996-2002 - Karl R. Hakimian and David Fries
+ *
+ * This file is part of datalink.
+ *
+ * Datalink 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.
+ *
+ * Datalink 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 datalink (see COPYING); if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+/*
+ * Linux version of Timex/Microsoft SDK for Timex datalink watches.
+ * SVGA needs a terminal when going to graphics mode.  This will take
+ * care of that.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/vt.h>
+#include <sys/ioctl.h>
+#include <sys/fcntl.h>
+
+#define VTFMT "/dev/tty%d"
+
+int open_vt()
+{
+	struct vt_stat vts;
+	int fd;
+	int newvt;
+	char buf[1024];
+
+/* Need to become root again to deal with vt's */
+	seteuid(0);
+
+	if ((fd = open("/dev/tty", O_RDWR)) == -1)
+	{
+		perror("open");
+		return (-1);
+	}
+
+/* See if we are on a VT. */
+	if (ioctl(fd, VT_GETSTATE, &vts) == 0)
+	{
+		close(fd);
+		return (0);
+	}
+
+/* We are not on a VT, switch to one. */
+	close(fd);
+
+	if ((fd = open("/dev/tty0", O_RDWR)) == -1)
+	{
+		perror("open");
+		return (-1);
+	}
+
+/* Get info on current vt. */
+	if (ioctl(fd, VT_GETSTATE, &vts) == -1)
+	{
+		perror("VT_GETSTATE");
+		return (-1);
+	}
+
+/* Open a new vt. */
+	if (ioctl(fd, VT_OPENQRY, &newvt) == -1)
+	{
+		perror("VT_OPENQRY");
+		return (-1);
+	}
+
+	if (newvt == -1)
+	{
+		fprintf(stderr, "No free vts to open\n");
+		return (-1);
+	}
+
+/* Make the new vt, the active vt. */
+	if (ioctl(fd, VT_ACTIVATE, newvt) == -1)
+	{
+		perror("VT_ACTIVATE");
+		return (-1);
+	}
+
+	if (ioctl(fd, VT_WAITACTIVE, newvt) == -1)
+	{
+		perror("VT_WAITACTIVE");
+		return (-1);
+	}
+
+	close(fd);
+	close(2);
+	close(1);
+	close(0);
+/*
+   Detach from controlling terminal here so that we can get a new
+   controlling terminal.
+*/
+	setsid();
+	sprintf(buf, VTFMT, newvt);
+	(void) open(buf, O_RDWR);
+	(void) open(buf, O_RDWR);
+	(void) open(buf, O_RDWR);
+
+/* No longer need root privs - drop them*/
+	seteuid(getuid());
+
+	return (vts.v_active);
+}
+
+void close_vt(int oldvt)
+{
+	int fd;
+	struct vt_stat vts;
+	struct vt_mode VT;
+	int vt;
+
+	if (!oldvt)
+		return;
+
+/* Need to become root again to deal with vt's */
+	seteuid(0);
+
+/* SVGA lib sets the tty change mode to require a call back.
+ * We aren't in graphics mode, so set it back to auto.
+ */
+	if( ioctl(0, VT_GETMODE, &VT) == -1)
+	{
+		perror("VT_GETMODE");
+		return;
+	}
+
+	VT.mode = VT_AUTO;
+	if( ioctl(0, VT_SETMODE, &VT)== -1)
+	{
+		perror("VT_SETMODE");
+		return;
+	}
+
+/* Get info on current vt. */
+	if (ioctl(0, VT_GETSTATE, &vts) == -1)
+	{
+		perror("VT_GETSTATE");
+		return;
+	}
+
+	vt = vts.v_active;
+
+/* Switch back to previous vt. */
+
+	if (ioctl(0, VT_ACTIVATE, oldvt) == -1)
+	{
+		perror("VT_ACTIVATE");
+		return;
+	}
+
+	if (ioctl(0, VT_WAITACTIVE, oldvt) == -1)
+	{
+		perror("VT_WAITACTIVE");
+		return;
+	}
+
+	close(0);
+	close(1);
+	close(2);
+	setsid();
+
+/* Open current vt. */
+	if ((fd = open("/dev/tty0", O_RDWR)) == -1)
+	{
+		perror("open");
+		return;
+	}
+
+/* Free up our old vt. */
+	if (ioctl(fd, VT_DISALLOCATE, vt) == -1)
+	{
+		perror("VT_DISALLOCATE");
+		return;
+	}
+
+	close(fd);
+
+/* No longer need root privs - drop them*/
+	seteuid(getuid());
+}
-- 
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