Uhh, no x05 is not a number. It's a control character, ^E. If you want a number expressed, change the printf you are piping to netcat, e.g.,

printf "510" | netcat 127.0.0.1 50000
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Scott

How can I use it as a number? As you can see I get $nm which is the length of the following section $methods. Is what I did correct?

You need to decide whether you are going to use hex characters to represent your data or ascii characters. If you are going to stick with your original code, then you need to be consistent throughout the code and treat the hex data as hex data, e.g.,

#!/usr/bin/perl -w
use strict;
use integer;
use Socket;

my $port = 50000; # Port to bind to
my $FORK = 0;     # Do we fork?

my $match = sprintf "\x05";

my $proto = getprotobyname('tcp');
socket(SERVER, PF_INET, SOCK_STREAM, $proto) or die "socket:$!";
setsockopt(SERVER, SOL_SOCKET, SO_REUSEADDR, pack("l", 1)) or die
"setsockopt: $!";
bind(SERVER, sockaddr_in($port, INADDR_ANY)) or die "bind: $!";
listen(SERVER, SOMAXCONN) or die "listen: $!";

if($FORK)
{
        my $pid = fork();
        die "fork: $!" if $pid < 0;
        exit if $pid;
}

for(;my $paddr=accept(CLIENT, SERVER); close CLIENT) {
        my ($ver,$nm,$methods) = ();
        recv(CLIENT,$ver,1,0);
        recv(CLIENT,$nm,1,0);
        if(($ver eq $match) && $nm)
        {
                my $char=ord($nm);
                print "Okay, getting $char methods\n";
                recv(CLIENT,$methods,$char,0);
                print "Got [$methods]\n";
        }
}

exit;
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Now, when you use the test line of hex chars to send to this server, you get the following results;

helphand@helphand:~> printf "\x05\x041234" | netcat 127.0.0.1 50000

Produces this output...

helphand@helphand:~> perl -w try.pl
Okay, getting 4 methods
Got [1234]
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Scott