#! /usr/bin/perl
use strict;
use warnings;

use 5.020;

# data to "send"
my @data = qw( 45 53 43 2F 56 50 2E 6E 65 74 10 03 00 00 00 00 50 57 52 3f 0D );

my $testfile = "/tmp/test.%d.dat";

sub write_test {
    my ( $num, @data ) = @_;
    my $file = sprintf $testfile, $num;

    open my $wh, ">", $file or die "open($file,w) failed: $!\n";

    print $wh @data;

    close $wh or die "close($file) failed: $!\n";
}

# see perldoc -f pack
write_test( 1, map { hex } @data );                   # print decimal value as text
write_test( 2, pack( 'C*', map { hex } @data ) );     # print unsigned char (octet) value
write_test( 3, pack( 'n*', map { hex } @data ) );     # print unsigned short (16-bit) in network (big-endian) order