I think this excertp from perlipc explains it a bit better than what you have: 
           use English '-no_match_vars';
           my $sleep_count = 0;

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

[download]
update: Just forgot.... You already read it... So here is a bit of explanation. The "open" returns a process ID, 0 or undef.
undef
We are out of processes. This is when open fails
0
This is the child process... The "or" part of your open. But it would be reached for undef too!
pid
This is for the parent process to have a pid to wait for.
s$$([},&%#}/&/]+}%&{})*;#$&&s&&$^X.($'^"%]=\&(|?*{%
+.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e

In reply to Re: Forked pipe open...or do??? by Skeeve
in thread Forked pipe open...or do??? by blahblah

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