Import of unmolested less-290.

1 files changed, 242 insertions, 0 deletions

diff --git a/usr.bin/less/signal.c b/usr.bin/less/signal.c
new file mode 100644
index 00000000000..9cbafa064b6
--- /dev/null
+++ b/usr.bin/less/signal.c
@@ -0,0 +1,242 @@
+/*
+ * Copyright (c) 1984,1985,1989,1994,1995  Mark Nudelman
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice in the documentation and/or other materials provided with 
+ *    the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+/*
+ * Routines dealing with signals.
+ *
+ * A signal usually merely causes a bit to be set in the "signals" word.
+ * At some convenient time, the mainline code checks to see if any
+ * signals need processing by calling psignal().
+ * If we happen to be reading from a file [in iread()] at the time
+ * the signal is received, we call intread to interrupt the iread.
+ */
+
+#include "less.h"
+#include <signal.h>
+
+/*
+ * "sigs" contains bits indicating signals which need to be processed.
+ */
+public int sigs;
+
+extern int sc_width, sc_height;
+extern int screen_trashed;
+extern int lnloop;
+extern int linenums;
+extern int wscroll;
+extern int reading;
+
+/*
+ * Interrupt signal handler.
+ */
+	/* ARGSUSED*/
+	static RETSIGTYPE
+u_interrupt(type)
+	int type;
+{
+#if OS2
+	SIGNAL(SIGINT, SIG_ACK);
+#endif
+	SIGNAL(SIGINT, u_interrupt);
+	sigs |= S_INTERRUPT;
+	if (reading)
+		intread();
+}
+
+#ifdef SIGTSTP
+/*
+ * "Stop" (^Z) signal handler.
+ */
+	/* ARGSUSED*/
+	static RETSIGTYPE
+stop(type)
+	int type;
+{
+	SIGNAL(SIGTSTP, stop);
+	sigs |= S_STOP;
+	if (reading)
+		intread();
+}
+#endif
+
+#ifdef SIGWINCH
+/*
+ * "Window" change handler
+ */
+	/* ARGSUSED*/
+	public RETSIGTYPE
+winch(type)
+	int type;
+{
+	SIGNAL(SIGWINCH, winch);
+	sigs |= S_WINCH;
+	if (reading)
+		intread();
+}
+#else
+#ifdef SIGWIND
+/*
+ * "Window" change handler
+ */
+	/* ARGSUSED*/
+	public RETSIGTYPE
+winch(type)
+	int type;
+{
+	SIGNAL(SIGWIND, winch);
+	sigs |= S_WINCH;
+	if (reading)
+		intread();
+}
+#endif
+#endif
+
+/*
+ * Set up the signal handlers.
+ */
+	public void
+init_signals(on)
+	int on;
+{
+	if (on)
+	{
+		/*
+		 * Set signal handlers.
+		 */
+		(void) SIGNAL(SIGINT, u_interrupt);
+#ifdef SIGTSTP
+		(void) SIGNAL(SIGTSTP, stop);
+#endif
+#ifdef SIGWINCH
+		(void) SIGNAL(SIGWINCH, winch);
+#else
+#ifdef SIGWIND
+		(void) SIGNAL(SIGWIND, winch);
+#endif
+#endif
+	} else
+	{
+		/*
+		 * Restore signals to defaults.
+		 */
+		(void) SIGNAL(SIGINT, SIG_DFL);
+#ifdef SIGTSTP
+		(void) SIGNAL(SIGTSTP, SIG_DFL);
+#endif
+#ifdef SIGWINCH
+		(void) SIGNAL(SIGWINCH, SIG_IGN);
+#endif
+#ifdef SIGWIND
+		(void) SIGNAL(SIGWIND, SIG_IGN);
+#endif
+	}
+}
+
+/*
+ * Process any signals we have received.
+ * A received signal cause a bit to be set in "sigs".
+ */
+	public void
+psignals()
+{
+	register int tsignals;
+
+	if ((tsignals = sigs) == 0)
+		return;
+	sigs = 0;
+
+#ifdef SIGTSTP
+	if (tsignals & S_STOP)
+	{
+		/*
+		 * Clean up the terminal.
+		 */
+#ifdef SIGTTOU
+		SIGNAL(SIGTTOU, SIG_IGN);
+#endif
+		clear_bot();
+		deinit();
+		flush();
+		raw_mode(0);
+#ifdef SIGTTOU
+		SIGNAL(SIGTTOU, SIG_DFL);
+#endif
+		SIGNAL(SIGTSTP, SIG_DFL);
+		kill(getpid(), SIGTSTP);
+		/*
+		 * ... Bye bye. ...
+		 * Hopefully we'll be back later and resume here...
+		 * Reset the terminal and arrange to repaint the
+		 * screen when we get back to the main command loop.
+		 */
+		SIGNAL(SIGTSTP, stop);
+		raw_mode(1);
+		init();
+		screen_trashed = 1;
+		tsignals |= S_WINCH;
+	}
+#endif
+#ifdef S_WINCH
+	if (tsignals & S_WINCH)
+	{
+		int old_width, old_height;
+		/*
+		 * Re-execute scrsize() to read the new window size.
+		 */
+		old_width = sc_width;
+		old_height = sc_height;
+		get_term();
+		if (sc_width != old_width || sc_height != old_height)
+		{
+			wscroll = (sc_height + 1) / 2;
+			screen_trashed = 1;
+		}
+	}
+#endif
+	if (tsignals & S_INTERRUPT)
+	{
+		bell();
+		/*
+		 * {{ You may wish to replace the bell() with 
+		 *    error("Interrupt", NULL_PARG); }}
+		 */
+
+		/*
+		 * If we were interrupted while in the "calculating 
+		 * line numbers" loop, turn off line numbers.
+		 */
+		if (lnloop)
+		{
+			lnloop = 0;
+			if (linenums == 2)
+				screen_trashed = 1;
+			linenums = 0;
+			error("Line numbers turned off", NULL_PARG);
+		}
+
+	}
+}