The data from your writes isn't being flushed to disk.
use FileHandle;
use strict;

my $data;
my $pid;

open(FILE, '+>outfile');
FILE->autoflush(1);
if(($pid = fork()))
 {
   sleep(1);
   print FILE 'ALPHA';
   sleep(5);
   print FILE 'BETA';
   wait();
 }
else
 {
   sleep(3);
   seek(FILE, 0, 0);
   read(FILE, $data, (stat(FILE))[7]);
   print $data, "\n";
   sleep(7);
   seek(FILE, 0, 0);
   read(FILE, $data, (stat(FILE))[7]);
   print $data, "\n";
 }
close(FILE);

[download]


will output:

ALPHA
ALPHABETA

which I think is what you want.

In reply to Re: Concurrency : FORK and knife by nardo
in thread Concurrency : FORK and knife by jsl

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