#! /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

# test.1.dat
00000000: 3639 3833 3637 3437 3836 3830 3436 3131  6983674786804611
00000010: 3031 3031 3131 3631 3633 3030 3030 3830  0101116163000080
00000020: 3837 3832 3633 3133                      87826313

# test.2.dat
00000000: 4553 432f 5650 2e6e 6574 1003 0000 0000  ESC/VP.net......
00000010: 5057 523f 0d                             PWR?.

# test.3.dat
00000000: 0045 0053 0043 002f 0056 0050 002e 006e  .E.S.C./.V.P...n
00000010: 0065 0074 0010 0003 0000 0000 0000 0000  .e.t............
00000020: 0050 0057 0052 003f 000d                 .P.W.R.?..