### Using Google Maps, Geocoding and PHP to find the distance between UK Postcodes

If you’re looking to make any kind of radius checker, delivery calculator etc, you will need to have some method of calculating this distance. Unfortunately for us in the UK, Royal Mail keep a tight grip on postcode data.

As a result, the best low-budget way of finding postcodes is by using the Google Maps api – which in itself isn’t 100% accurate (but good enough).

So we can use the following code:

```<?php
// Specify Postcodes to Geocode
\$postcode1 = 'BH151DA';
\$postcode2 = 'BH213AP';

// Geocode Postcodes & Get Co-ordinates 1st Postcode
\$data1 = @file_get_contents(\$pc1);
\$result1 = explode(",", \$data1);
\$custlat1 = \$result1[2];
\$custlong1 = \$result1[3];

// Geocode Postcodes & Get Co-ordinates 2nd Postcode
\$data2 = @file_get_contents(\$pc2);
\$result2 = explode(",", \$data2);
\$custlat2 = \$result2[2];
\$custlong2 = \$result2[3];

// Work out the distance!
\$pi80 = M_PI / 180;
\$custlat1 *= \$pi80;
\$custlong1 *= \$pi80;
\$custlat2 *= \$pi80;
\$custlong2 *= \$pi80;

\$r = 6372.797; // mean radius of Earth in km
\$dlat = \$custlat2 - \$custlat1;
\$dlng = \$custlong2 - \$custlong1;
\$a = sin(\$dlat / 2) * sin(\$dlat / 2) + cos(\$custlat1) * cos(\$custlat2) * sin(\$dlng / 2) * sin(\$dlng / 2);
\$c = 2 * atan2(sqrt(\$a), sqrt(1 - \$a));

// Distance in KM
\$km = round(\$r * \$c, 2);

// Distance in Miles
\$miles = round(\$km * 0.621371192, 2);

echo 'The distance between '.\$postcode1.' and '.\$postcode2.' is '.\$km.'Km ('.\$miles.' miles).';

?>```

You could use \$result1[0] and \$result2[0] to check codes. If the value is anything other than 200 the postcode is invalid. Also note UK is also searched for to guarantee correct results!

The result is also rounded to make sure we only have 2 decimal places. Make sure your postcodes do not have any spaces in when they go to Google, if you’re collecting them from a form maybe use:

```function nowhitespace(\$data) {
return preg_replace('/\s/', '', \$data);
}
\$postcode1 = nowhitespace(\$postcode1);```

to remove all spaces before processing, and the following to check it’s ok after processing:

```if ((\$result1[0] != 200) || (\$result2[0] != 200)) {
echo "<p>Invalid Postcode(s) Entered. Please try again.</p>";
} else {```

Good luck!

### Validating email addresses in PHP with Preg filters, DNS, MX Servers and other checks

UPDATE: It is now easier to send a confirmation email to the provided address to validate it, or to use a framework than a custom script.

There are many tutorials online that show users how to validate an email address, but most do it wrong. This means many websites will reject valid addresses such as customer/[email protected] or abc!def!xyz%[email protected] (yes, they are valid!) with the following expression:

### SPF Records for Google Apps Hosted Mail – avoiding rejected emails

Using Google Apps for your domain’s email? Well you definately need to set up some SPF records.
It seems yahoo is extremely strict when it comes to checking for SPF records on a domain, and bounces anything with missing records. Many other email providers like hotmail simply SPAM your message straight away.

But, they recommend using

That’s all fine and well…but what about the official website? Oddly, they recommend using – instead of ~ (http://www.openspf.org/FAQ/Common_mistakes)

But seeing as it’s google hosting my mail, I’ve been using ~ successfully for some time now, with no more bounces.

## Testing whether you’re configured correctly

Easy, just send an email to [email protected] and you’ll get a bounce right back with the SPF status in (http://www.openspf.org/Tools).

## How can I configure my server?

If you have access to all your DNS records for your domain you can add it yourself (for example through WHM or root plesk panel) but on most shared hosts just fire off an email to the support team who will add the record for you.

On Plesk & Cpanel you can add either a SPF record or a TXT record through your DNS editor, making it easy to do this yourself.

### Automatic Local, FTP and Email Backups of MySQL Databases with Cron

I’ll start by saying this is not all my own code, it is based on dagon design’s original release in 2007 (Automatic MySql Backup Script) but this version builds on their version 2.1 to add FTP support.

What this script does:

• Backup all of your MySQL databases on a server individually, then package them into a single tar.
• Save that tar locally, on a FTP server or even email it to you

What you need:

• PHP
• MySQL
• An account with relevant mysql access (it needs access to the databases you wish to backup)

Zip containing dbbackup.php & dbbackupconfig.php – dbbackup.zip

## What I’ve added:

To upload to a remote FTP server, I added this to the config file:

```######################################################################
## FTP Options
######################################################################

// Use FTP Option?
\$useftp = true;

// Use passive mode?
\$usepassive = true;

// FTP Server Address
\$ftp_server = 'host';

```

and this to the main file below email sending:

```// do we ftp the file?
if (\$useftp == true) {
\$file = \$BACKUP_DEST.'/'.\$BACKUP_NAME;
\$remote_file = \$BACKUP_NAME;

// set up basic connection
\$conn_id = ftp_connect(\$ftp_server);

// turn passive mode on?
ftp_pasv(\$conn_id, \$usepassive);

// upload a file
if (ftp_put(\$conn_id, \$remote_file, \$file, FTP_BINARY)) {
echo "successfully uploaded to ftp: \$remotefile\n";
} else {
echo "There was a problem while uploading \$remotefile\n";
}

// close the connection
ftp_close(\$conn_id);
}```

That’s all!

### Stripping everything but letters and numbers from a string in PHP with preg_replace

Useful for a number of things including username and anything else you don’t want ANY special chars in, leaving only alphanumeric digits.

```<?php
\$string = 'us\$\$er*&^[email protected]@e';
\$string = cleanabc123(\$string);
function cleanabc123(\$data)
{
\$data = preg_replace("/[^a-zA-Z0-9\s]/", "", \$data);
return \$data;
}
// This will be 'username' now
echo \$string;
?>```

And if you wanted it to also remove whitespace, you could change the function by removing the \s whitespace character.

`\$data = preg_replace("/[^a-zA-Z0-9]/", "", \$data);`

### Remove whitespace (spaces) from a string with PHP and preg_replace

Seeing as ereg_replace and that whole family has been depreciated in the newer PHP releases it’s surprising how many sites still show and use it.

This simple function strips out whitespace from a string. Could be useful in taking spaces out of usernames, id’s, etc.

```<?php
\$string = 'us er na  me';
\$string = nowhitespace(\$string);
function nowhitespace(\$data) {
return preg_replace('/\s/', '', \$data);
}
// This will be 'username' now
echo \$string;
?>```

You could use this to make all whitespace only 1 space wide by changing the ” in the following line.

`return preg_replace('/\s/', ' ', \$data);`

Last example modified from the PHP manual.

### Using PHP to strip a user IP address into subnets and filter out characters

Found it very difficult to find a simple solution to this problem – you want to display the submittor’s IP address on a webpage where it will be publicly available, but obfuscate some characters.

You want 255.255.255.255 to become 255.255.255.x or something, right?

## Preg_replace() an IP

So, assuming we have the user’s IP address, for this we could use the following server variable:

```// Displays user IP address
```

We can manipulate this with preg_replace.

```// Displays user IP address with last subnet replaced by 'x'
\$ip = preg_replace('~(\d+)\.(\d+)\.(\d+)\.(\d+)~', "\$1.\$2.\$3.x", \$ip);```

So the code to get and change this IP would be:

```// Sets user IP address
// Sets user IP address with last subnet replaced by 'x'
\$ip = preg_replace('~(\d+)\.(\d+)\.(\d+)\.(\d+)~', "\$1.\$2.\$3.x", \$ip);
// Displays user IP address as altered.
echo \$ip;```

Of course, if you’re happy to just cut off the end then you can use the substr function to trim a number of characters off.

I’ll revise this to validate and deal with proxies another time.

### Integrating your existing site into phpBB3

One way of making an existing site dynamic is to integrate it with a phpBB forum. This is actually very easy, and allows you to quickly pull data about your users; control page access by groups and more.

### Page type

The page you’re integrating phpBB with needs to be a php page! (pretty obvious really seeing as phpBB is a PHP forum)

### Connect to phpBB to get variables, etc.

You will need to include a file containing the phpBB connection information (essentially plugs the page into the rest of phpBB). This file should contain the following

```<?php
define('IN_PHPBB', true);
\$phpbb_root_path = (defined('PHPBB_ROOT_PATH')) ? PHPBB_ROOT_PATH : 'change_this_to_phpbb_dir';
\$phpEx = substr(strrchr(__FILE__, '.'), 1);
include(\$phpbb_root_path . 'common.' . \$phpEx);
// Start session management
\$user->session_begin();
\$auth->acl(\$user->data);
\$user->setup();
?>```

Save this file as phpbb.php, or put this code in some other file you will include in every page you want to integrate. All this code does is define where phpbb can be found, and include the common.php file from within phpbb. It also starts a user session, which we can use on our page.

### Get our page to interact with phpBB

So now we go to the page we want to integrate with phpBB. In this case I’m going to use a blank file as an example but obviously you can use any file. This bit of code checks to see if the user is logged in or not and displays an appropriate message

```<?php include_once("phpbb.php"); ?>
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>phpBB conn test</title>
<body>
<?php
// PHPBB LOGIN AUTH
if (\$user->data['user_id'] == ANONYMOUS) {
?>
Welcome, anomalous!
<?php
} else {
?>
Welcome back, <?php echo \$user->data['username_clean']; ?> | You have <?php echo \$user->data['user_unread_privmsg']; ?> new messages
<?php } ?>
</body>
</html>```

This will display “Welcome, anomalous!” if you’re not logged into phpBB or “Welcome back, username | You have 0 new messages” if you are logged in. Note the placement of the include_once ABOVE the <head> tag – this is required if you don’t want any errors.

This is a very simple example and doesn’t tell our user how to log in or log out…which are pretty critical activities.

The simple way to login is to push all logins through the phpBB system. This form does just that.

```<form method="POST" action="forum/ucp.php?mode=login">
Remember Me?: <input type="checkbox" name="autologin"><br />
<input type="hidden" name="redirect" value="">
</form>```

This collect the login data and posts it to the phpBB ucp.php. We can make phpBB redirect the user back to any page by changing the value of the redirect input field.

`<input type="hidden" name="redirect" value="../somefile.php">`

Once this form has been posted the user will be logged in. But how about logging out?

### Logging out of phpBB

You could just navigate to the forum and click the link there, but hey – might as well do this in as few clicks as possible. So we need a link to log out…

`<a href="somefile.php?cp=logout">Log Out</a>`

and in the same file we could put the following at the top of the document:

```<?php
// check for logout request
\$cp = \$_GET['cp'];
// is it a logout? then kill the session!
if (\$cp == "logout") {
\$user->session_kill();
\$user->session_begin();
echo "Successfully Logged Out.";
}
?>```

So when cp is set to logout (when the user visits somefile.php?cp=logout) the session containing the userdata is destroyed and reset. ‘Succssfully Logged Out’ is also shown for the user’s benefit.

### Combining conditional, login & logout

As a summary, I’ve combined what we looked at above.

In phpbb.php:

```<?php
define('IN_PHPBB', true);
\$phpbb_root_path = (defined('PHPBB_ROOT_PATH')) ? PHPBB_ROOT_PATH :  'change_this_to_phpbb_dir';
\$phpEx = substr(strrchr(__FILE__, '.'), 1);
include(\$phpbb_root_path . 'common.' . \$phpEx);
// Start session management
\$user->session_begin();
\$auth->acl(\$user->data);
\$user->setup();
?>```

In somefile.php:

```<?php include_once("phpbb.php");
// check for logout request
\$cp = \$_GET['cp'];
// is it a logout? then kill the session!
if (\$cp == "logout") {
\$user->session_kill();
\$user->session_begin();
echo "Successfully Logged Out.";
}
?>
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>phpBB conn test</title>
<body>
<?php
// Page login notice
if (\$user->data['user_id'] == ANONYMOUS)
{
?>
<center>Welcome! Please login below or click <a href="forum/ucp.php?mode=register">here</a> to register.<br />