Isn't this just easier?

#! perl -slw
use strict;

my $pid = open IN, '-|',
    qq[ perl -E"say scalar localtime, sleep 1 for 1.. $ARGV[0]" ]
    or die $!;

eval {
    local $SIG{ ALRM } = sub {
        kill -9, $pid;
        warn 'timeout';
    };
    alarm 5;
    waitpid $pid, 0;
    alarm 0;
};

while( <IN> ){
   print;
}

__END__
c:\test>junk 3
Tue Jun  8 15:33:04 20101
Tue Jun  8 15:33:05 20101
Tue Jun  8 15:33:06 20101

c:\test>junk 4
Tue Jun  8 15:33:09 20101
Tue Jun  8 15:33:10 20101
Tue Jun  8 15:33:11 20101
Tue Jun  8 15:33:12 20101

c:\test>junk 5
timeout at C:\test\junk.pl line 11.
[download]

Only if the child prints less than a pipe's buffer's worth of information (64k?). That's very small these days.

Only if the child prints less than a pipe's buffer's worth

That (conservatively), probably covers 85% of the uses of such code. Are you telling me that you don't see a relatively simple modification to cater for the rest?

I mean without resorting to forks & execs and no-blocks and selects and events&globals, state-driven spaghetti code?

---

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"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

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