Re: [rt.cpan.org #59322] SetConsoleCtrlHandler function not supported

Thu Jul 15 05:30:45 2010: Request 59322 was acted upon.
Transaction: Correspondence added by [email protected]
       Queue: Win32-Console
     Subject: Re: [rt.cpan.org #59322] SetConsoleCtrlHandler function not supported
   Broken in: 0.09
    Severity: Important
       Owner: Nobody
  Requestors: [email protected]
      Status: open
 Ticket <URL: https://rt.cpan.org/Ticket/Display.html?id=59322 >


Chris Marshall via RT wrote:
> 
> So the problem appears that the 1st Ctrl-C is caught
> but something in the readline part prevents reloading
> of the signal handler so an immediate Ctrl-C will
> send another "SIGINT" which will not be caught and
> then the console control handler will be called which
> offers to exit the CMD console.  (Presumably, the
> default handler was also called from the 2nd Ctrl-C
> in perl which is why that application exited....
> 
> I think I've convinced myself it is tied in with the
> Term::ReadLine::Perl stuff but don't know how it
> could be fixed.  If that is the case, having the
> missing SetConsoleCtrlHandler() routine might not
> help either.

Looks like 1) you have to stop reading after you get an EOF
from readline; 2) readline seems to catch the first ^C and
quits working after that - then you can catch ^C OK; 3) you
can't create a new Readline obj after it fails.

New test case:

use strict;
use warnings;
use Term::ReadLine;

$| = 1;
my $cnt = 0;
sub handler {
	print "Caught a SIG '$_[0]' - continuing\n";
	die "Got three" if ++$cnt > 2;
}
$SIG{INT}  = \&handler;

my $term = new Term::ReadLine 'ProgramName';
while (1) {
	my $input = $term->readline('prompt> ');
	if (not defined $input) {
		print "EOF on input\n";
	} elsif ($input eq 'q') {
		print "quitting\n"; exit;
	} else {
		printf "Got: '%s'\n", $input;
	}
	Win32::Sleep(1000);	# stop runaway console
}

__END__

There's definitely some work that could be done in readline
to make this a little more friendly and some docs to go with.