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* Re:  rc and signal handlers
@ 1992-11-05 22:00 Byron Rakitzis
  0 siblings, 0 replies; 5+ messages in thread
From: Byron Rakitzis @ 1992-11-05 22:00 UTC (permalink / raw)
  To: malte, rc

signal handlers ARE function definitions. They just have the
added feature that they get run at "interrupt level". If
it's not obvious that you can't "return" from a signal
handler, then you need to think a little more carefully
about what signals are.

btw,

; fn sigint { echo hi }
; sigint
hi
;


^ permalink raw reply	[flat|nested] 5+ messages in thread
* rc and signal handlers
@ 1992-11-05 20:45 malte
  1992-11-05 23:16 ` Chris Siebenmann
  0 siblings, 1 reply; 5+ messages in thread
From: malte @ 1992-11-05 20:45 UTC (permalink / raw)
  To: rc

I just came across a situation were I want to temporarily change the
sematics of a signal handler, say during the execution of a function.

	fn doit {
		sighdlr = `` $nl { whatis -s | fgrep 'fn sigint' }
		...
		eval $sighdlr
	}

doesn't work, of course. What is needed is a kind of local signal handler,
or a way to put a signal handler definition into a variable like

	fn doit {
		whatis fn sigint var
		...
		eval $var
	}

I suggest local signal handlers and local functions.

Also, the man-page is not too clear about signals:

	"Only signals that are being ignored are passed on to programs run by rc"

The should read "signals that are being caught", I guess. Signal handler
definitions look like functions but are *not*; it should be stated that one
cannot "return" from a signal handler.

Malte


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~1992-11-06 12:03 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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1992-11-04 12:45 ` set subtract malte
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1992-11-05 22:00 Byron Rakitzis
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1992-11-05 20:45 malte
1992-11-05 23:16 ` Chris Siebenmann

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