Re: Signalling during I/O

[Reuben Thomas <rrt@...>]

>   here's what i did:  removed the call to signal(i, SIG_DFL) in
>   laction() and replaced the 2 calls to signal(SIGINT, ...) in lcall()
>   with sig_catch(SIGINT, ...) where sig_catch() is
>
>       static void
>       sig_catch(int sig, void (*handler)(int))
>       {
>         struct sigaction sa;
>         sa.sa_handler = handler;
>         sa.sa_flags = 0;
>         sigemptyset(&sa.sa_mask);
>         sigaction(sig, &sa, 0);		/* XXX ignores errors */
>       }
>
>   i don't know if these changes create new problems though
>   (besides being non-ansi)

Wow, that does it for me.

> to test this hodge podge of signal semantics, i used the following

Hodge-podge? Looks quite simple to me, simpler than what was there
before...

As to whether it's nastier to do it like this or the ANSI way, as Luiz
admits, it's a "corner" of ANSI C (e.g. it doesn't work at all on some
platforms, like EPOC, and it's badly-defined enough that the glibc
manpages advise programmers not to use signal).

Since this doesn't involve a change to liblua or liblualib, I'd be very
much in favour of adding it (at least as an option) to lua.c.

> ----------------------------
> function foobar()
> 	local a
> 	if pcall(function() a=io.stdin:read('*a') end) then
> 		if a=="" then os.exit(0) end	-- eof
> 		io.write(string.gsub(a, "%c", "."), "\n")
> 	else
> 		print'boo-boo'
> 	end
> end
>
> while 1 do foobar() end
> ----------------------------

Nice!

-- 
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