You are suffering from buffering. 
use IO::Handle;
STDOUT->autoflush(1);

while ($num) {
   print "$num\r";
   $num--;
   sleep 1;
}

[download]
or 
use IO::Handle;

while ($num) {
   print "$num\r";
   STDOUT->flush();
   $num--;
   sleep 1;
}

[download]

In reply to Re: Perl only prints complete lines? by ikegami
in thread Perl only prints complete lines? by Anonymous Monk

Title:
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