Skip to content
Fetching contributors…
Cannot retrieve contributors at this time
42 lines (35 sloc) 1006 Bytes
# -*- coding: utf-8 -*-
# Copyright (C) 2011 Rocky Bernstein <rocky@cpan.org>
# Subsidiary routines used to "pack" and "unpack" TCP messages.
use strict; use warnings; no warnings 'redefine';
package TCPPack;
use POSIX qw(ceil log10);
use Exporter;
our (@ISA, @EXPORT);
@ISA = qw(Exporter);
@EXPORT = qw(TCP_MAX_PACKET LOG_MAX_MSG pack_msg unpack_msg);
use constant TCP_MAX_PACKET => 8192;
use constant LOG_MAX_MSG => ceil(log10(TCP_MAX_PACKET));
sub pack_msg($)
{
my $msg = shift;
# A funny way of writing: '%04d'
my $fmt = sprintf '%%0%dd' , LOG_MAX_MSG;
return sprintf($fmt, length($msg)) . $msg;
}
sub unpack_msg($)
{
my $buf = shift;
my $length = int(substr($buf, 0, LOG_MAX_MSG));
my $data = substr($buf, LOG_MAX_MSG, LOG_MAX_MSG + $length);
$buf = substr($buf, LOG_MAX_MSG + $length);
return ($buf, $data);
}
# Demo
unless (caller) {
my $buf = "Hi there!";
my $msg;
($buf, $msg) = unpack_msg(pack_msg($buf));
print "$msg\n";
}
1;
Jump to Line
Something went wrong with that request. Please try again.