You are surprisingly right,

I somehow always regarded 

$pid = open(KID_TO_WRITE, "|-");

[download]
trick as a way to talk with only one child, but if we rewrite it like this: 
$fh = new FileHandle;
my $sleep_count = 0;

do {
        $pid = open($fh, "|-");
        unless (defined $pid) {
                warn "cannot fork: $!";
                die "bailing out" if $sleep_count++ > 6;
                sleep 10;
        }
} until defined $pid;

my (@some_data)=qw[a be ce];
if ($pid) {
         print $fh @some_data;
         close($fh) || warn "kid exited $?";
} else {
        while (<STDIN>) {
                print "GOT: $_\n"; # child's STDIN is parent's KID
        }
        exit;  # don't forget this
};

[download]
then we get to hold whole array of different $fd's, each for talking with one child. This would be clean and reliable, exactly what I wanted.

Thanx.

In reply to Re^2: How to tell a child what to do? by Eyck
in thread How to tell a child what to do? by Eyck

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