You need to print a "control line feed" after each send and receive, also, turn auto-flush on (error on my behalf - it's okay to do this, but not necessary - see Update at bottom):

use IO::Socket qw(crlf); # now you can use CRLF constant
$|++;                    # non-buffered
[download]

# in server:
print $new_sock $_, CRLF;

# in client:
print $sock "Hello there", CRLF;
[download]

# server
use strict;

use IO::Socket qw(:crlf);

my $sock = new IO::Socket::INET (
                                LocalAddr => 'localhost',
                                LocalPort => 10000,
                                Proto => 'tcp',
                                Listen => 1,
                                Reuse => 1,
                                );

die "Could not create socket\n" unless $sock;

my $new_sock = $sock->accept();

while(<$new_sock>) {

     print $new_sock $_, CRLF;

  }
close($sock);

#------------------------------
# client

use strict;

use IO::Socket qw(:crlf);

my $sock = new IO::Socket::INET (
                                 PeerAddr => 'localhost',
                                 PeerPort => 10000,
                                 Proto => 'tcp',
                                 );
die "could not create socket\n" unless $sock;

print $sock "Hello there", CRLF;

print $sock->getline();

close($sock);
[download]

Oh yeah - go ye forth and get Network Programming with Perl.

Update!
runrig reminded me that $|++ flushes STDOUT by default, not the socket (silly /me), so that should be $socket->autoflush(), but, as of IO::Socket version 1.18 autoflush is on by default. Sorry about that. runrig++

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
F--F--F--F--F--F--F--F--
(the triplet paradiddle)