I tried this once

Just once? Okay... Show us what you tried.

I updated the question with the code.

Hello! I am having trouble with a socket server and client interaction. I want to execute a perl script by default when a client TELNETs into my server. I tried this once, but it ran the script on the server's side, and not the client's side. Help?!

You mean to say, when somebody (a client) speak (opens socket) to you (your server), you want to make that somebody sing opera (run your program)?

You can't do that without prior agreement (client install your software ), esp using telnet, since that is mind control (security violation)

Indeed.

Though perhaps what the questioner actually wants is to run the script at the server end, but display the script's output at the client end? (And is just not expressing that especially clearly.) That is, after all, a fairly common desire.

In which case, it's something along these lines...

my $output = `perl the-script.pl`;
print CLIENT $output;
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perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

I tried it, and added the lines:

my $output = `perl the-script.pl`;
print CLIENT $output;
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But it just prints "smile from the server" and doesnt run the perl program. :-/

Here is the total code:

#! /usr/bin/perl -w
# server0.pl
#--------------------

#use strict;
use Socket;

# use port 7890 as default
my $port = shift || 7890;
my $proto = getprotobyname('tcp');

# create a socket, make it reusable
socket(SERVER, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
setsockopt(SERVER, SOL_SOCKET, SO_REUSEADDR, 1) or die "setsock: $!";

# grab a port on this machine
my $paddr = sockaddr_in($port, INADDR_ANY);

# bind to a port, then listen
bind(SERVER, $paddr) or die "bind: $!";
listen(SERVER, SOMAXCONN) or die "listen: $!";
print "SERVER started on port $port ";

# accepting a connection
my $client_addr;
while ($client_addr = accept(CLIENT, SERVER))
{
# find out who connected
my ($client_port, $client_ip) = sockaddr_in($client_addr);
my $client_ipnum = inet_ntoa($client_ip);
my $client_host = gethostbyaddr($client_ip, AF_INET);
# print who has connected
print "got a connection from: $client_host","[$client_ipnum] ";
# send them a message, close connection
    print CLIENT "Smile from the server\n";
#    open CLIENT, ("system ("perl io-test-1.pl");");
#    open (CLIENT, "system ("perl io-test-1.pl")");
#    open CLIENT, "do `perl io-test-1.pl`";
#my $status = CLIENT, system("perl io-test-1.pl");
#CLIENT $status = CLIENT, system("perl io-test-1.pl");
    my $output = `perl io-test-1.pl`;
    print CLIENT $output;
    close CLIENT;
}
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