Path: utzoo!utgpu!jarvis.csri.toronto.edu!torsqnt!hybrid!becker!bdb
From: bdb@becker.UUCP (Bruce Becker)
Newsgroups: unix-pc.general
Subject: Re: Window switching killing programs
Message-ID: <2209@becker.UUCP>
Date: 14 Jan 90 13:27:58 GMT
References: <1990Jan14.053423.29887@stb.uucp>
Reply-To: bdb@becker.UUCP (Bruce Becker)
Organization: G. T. S., Toronto, Ontario
Lines: 35

In article <1990Jan14.053423.29887@stb.uucp> michael@stb.UUCP (Michael Gersten) writes:
|
|What EXACTLY happens to a program when a window change occurs? What
|EXACTLY happens to input queues/terminal lines?
|
|I have two programs that can detect a change in the active window.
|One prints "EXIT" and exits the program. There is no string "EXIT"
|anywhere in the program; at that point, unless some signal that
|I'm not expecting is killing the program there is no way to leave
|without printing a message.
|
|The other program is "less", and if it is reading a pipe when the active
|window changes, then it aborts reading the pipe and thinks it is working
|with an empty file.
|
|Any ideas?

	The window system sends the "SIGWIND" signal
	to process involved in a window change. Here's
	the entry in "/usr/include/sys/signal.h" -

	#sccs	"@(#)uts/kern/sys:signal.h	1.1"
	[...]
	#define SIGWIND	20	/* window change */
	[...]

	It looks like these programs are catching the
	signal and doing something unuseful with it.
	Or else there's some system bug...

-- 
  ,,,,	 Bruce Becker	Toronto, Ont.
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