Well, I did find a way to make it work under Win32 (tested under Win98 and WinNT). This seems to indicate several bugs in Perl 5.6.0 for Win32. But first, the code that works:

# The following hack allows $SIG{INT} to work under Win32:
my $child= fork();
if(  defined $child  &&  0 == $child  ) { # Child:
    exit( 0 );
}

# Parent:
my $go= 1;
$SIG{INT}= sub { $go= 0; warn "Got INT\n" };
my $i= 0;
while(  $go  &&  $i < 10_000_000  ) {
    $i++;
}
print "Done: $i\n";
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Now, I recall reading that $$ is supposed to be negative for the threads that are created by Win32 Perl's pseudo-fork(). But in coming up with the above code I found that $$ is negative in the parent and positive in the child. kill and waitpid seem to return immediately after doing nothing. The parent exit()ing sometimes kills the "child" thread and sometimes lets it run. I even had a case where CTRL-C caused the parent to start over (and no, I quadruple-checked that it wasn't the child acting like the parent).

And 2 of 4 times using this code and hitting CTRL-C caused Perl to panic under WinNT (no panics after dozens of runs under Win98 -- Win98 doesn't care nearly as much if your code goes romping mearilly through random chunks of RAM).

Anyone been keeping up with p5p and know how much of this is already know to the developers. I would think most of this is since it so easy to find and they'd be intersted in testing the new pseudo-fork(). tilly? :)

I keep up enough to have random tidbits, but I don't follow closely. Sorry. I think this should definitely be reported as a bug though. Ben

However, I searched the perlbug database and couldn't find a problem like this. In fact, I verifed that others are successfully using %SIG, so I assume that I must be misunderstand something. So let me see if I understand this. The following should generate an infinite loop which should do nothing but fill the screen with numbers and cannot be broken out of with CTRL-C:

#!/usr/bin/perl -w
use strict;

$SIG{INT} = 'IGNORE';
my $count=0;
while (){
    print $count++;
}
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Cheers,
Ovid

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We offered a number of failed suggestions to this on the CB. =) Win9x makes things a bit harder. The select trick won't work well to capture keyboard input and the MS way is supposedly rather nasty for quick hacks.

I'd like to make a simple sniff for input loop to solve his question but can't do so. Is there an easier way on Win9x boxes to do keyboard capture that is non-blocking that I don't know of?

What I finally recommend is this, which I sometimes use for scripts that restart themselves with cron if they die:

open LINETO, ">./lineto.txt";
$oldfh = select(LINETO); $| = 1; select($oldfh);

for ($1 etc. etc.) {
  #do you stuff here
  ##done with stage $i?
  seek LINETO,0,0;
  print LINETO "$i\n";
  #post cleanup.
}
print LINETO, "Finito\n";
close LINETO;
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But I have no idea what kind of slowdown that would add, esp. since it would depend on OS and FileSystem load.

--
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honk() if $you->love(perl)