kgaughan

~^(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)*[a-z](?:[a-z0-9-]*[a-z0-9])$~

kgaughan

function can_host_receive_mail($host) {
    if (checkdnsrr($host, 'MX')) {
        return true;
    }
    // We try the host itself if it exists no MX records were found, as per
    // RFC2821.
    if (checkdnsrr($host, 'A') || checkdnsrr($host, 'AAAA')) {
        $h = @fsockopen($host, 25, $errno, $errstr, 30);
        if ($h) {
            fclose($h);

kgaughan

function is_well_formed_hostname($host) {
    return preg_match('~^(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)*[a-z](?:[a-z0-9-]*[a-z0-9])$~', $host);
}

kgaughan

function is_valid_local_part($local) {
    // I'm not entirely sure about this regex, but it seems to fit was RFC2822 specifies.
    return preg_match("@^[-a-z0-9!#\$%&'*+/=?^_`{|}~]+(\.[-a-z0-9!#\$%&'*+/=?^_`{|}~]+)*\$@", $local);
}

function is_well_formed_email_address($email) {
    // We ignore legacy addresses and local addresses.
    $parts = explode('@', $email, 2);
    if (count($parts) != 2) {
        return false;

kgaughan

if (!is_well_formed_email_address($email)) {
    echo "Email address is not well-formed.\n";
} else {
    list(, $host) = explode('@', $email, 2);
    if (can_host_receive_mail($host)) {
        echo "Host $host can receive mail.\n";
    } else {
        echo "Host $host can't receive mail.\n";
    }
}

kgaughan

#!/usr/bin/env python
#
# pipedarg
# by Keith Gaughan <http://talideon.com/>
# 
# The software is hereby placed in the public domain, and the author
# disclaims ownership over it and all responsibility for any damage caused
# directly or indirectly through its use. It may be freely copied and/or
# mangled, provided that altered versions have a different name and are
# not attributed to the original author.

kgaughan

from itertools import count

def sieve():
    """
    The Sieve of Erastosthenes.

    If you wanted to speed this up, your best bets are to throw in a wheel.
    The heapq module's already written in C, so that's as fast as it's going
    to get, though if you can think of a way to avoid quite so many calls to
    heapq.heapreplace() (or prevent if from sifting the heap prematurely for

kgaughan

<?php
/*
 * Two annoying omissions from PHP are the lack of array_all() and array_any(), which check if
 * a condition represented by a callback holds for all or any of the elements in an array. 
 */

function array_all(array $arr, $cb) {
    foreach ($arr as $e) {
        if (!call_user_func($cb, $e)) {
            return false;

kgaughan

<?php
function php_is_so_broken() {
    // Note: This appears to have been fixed somewhere in the 5.1 series,
    // so no more brokenness. Hurray!
    foreach (func_get_args() as $arg) {
        echo "$arg ";
    }
    echo "\n";
}

kgaughan

import smtpd
import asyncore

smtpd.DebuggingServer(('127.0.0.1', 1025), None)
asyncore.loop()