recv is for datagram protocols (like UDP). You need to use sysread when using a stream protocol (like TCP). 

# Send request.
print $oSocket $sSend
   or die("Unable to write to the socket: $!\n");

# Receive response.
my $data_read = "";

my $rv;
do {
   $rv = sysread($oSocket, $data_read, 4096, length($data_read));
   die("Unable to read from the socket: $!\n") if not defined $rv;
} while $rv;

[download]

Tested.

Update: Added code.

In reply to Re: No data received on client socket by ikegami
in thread No data received on client socket by rbi

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