Code

Create a MySQL TIMESTAMP from a Unix Timestamp

Tue, 21 Jul 2009 23:17:00 +0100

This simple function formats a Unix Timestamp as one ready to be inserted into MySQL.

function mktimestamp($epoch) {
	$epoch = date("Y-d-m H:i:s", $epoch);
	
	return $epoch;
}

Correct Format for Producing MySQL TIMESTAMPS

Tue, 21 Jul 2009 20:00:00 +0100

This is the correct formatting to use when using the date() function when building MySQL TIMESTAMPS.

    date("Y-d-m H:i:s");

Example: 2009-21-07 20:58:15

Other than that it’s pretty simple. Unfortunately, MySQL doesn’t support Unix Timestamps, which would mean that it’s a good idea to have a function to deal with this.

OPML Sample

Sun, 19 Jul 2009 00:25:00 +0100

This is a basic OPML sample to base OPML building scripts on top of. Pulled from a nearly blank OmniOutliner OPML export. The fields “text”, “Date”, “URL” can be changed to how you desire.



  
    example

Geocode an address with the Google Maps API

Fri, 17 Jul 2009 21:44:00 +0100

This ~~code snippet~~ mini-project, returns a geocode (that is, Latitude and Longitude) from a given address.

Note: This requires that you obtain your own Google Maps API Key and on it’s own violates the Google Maps API Terms and Conditions. In short, you must accompany this with a map, then you’re safe.

It features some basic error handling, which will catch the status messages returned. Unfortunately, this makes the code a little messy, but otherwise you’d have nothing returned.

	$key = "your-key";
	
	/* Given data */
	$street = "My Street";
	$town = "My Town";
	$country = "My Country";
	$postcode = "My Postcode";
	
	$address = urlencode($street . ", " . $town . ", " . $country);

	$xml_input = "http://maps.google.com/maps/geo?q={$address}&output=xml&oe=utf8&sensor=false&key={$key}";
	$xml = simplexml_load_file($xml_input);
	
	$status =  $xml->Response->Status->code; // returned status code
	
	if ($status == "500") {
		echo "Request could not be completed due to a server error. Please try again.";
	} 
	if ($status == "601") {
		echo "You didn't pass an address. Please try again.";
	}
	if ($status == "602") {
		echo "The address could not be found. Please try again.";
	}
	if ($status == "603") {
		echo "The address cannot be returned due to legal or contractual reasons.";
	}
	if ($status == "610") {
		echo "The API key used is invalid or doesn't match the domain.";
	}
	if ($status == "620") {
		echo "Too many requests have been sent. You've either reached the limit, or sent too many at once.";
	}
	else {
		echo "Coordinates";
		$coords = $xml->Response->Placemark->Point->coordinates; // return coords
		// splits and reverses the returned string to make it correct
		$latlong = explode(",", $coords);
		echo $latlong[1] . ", " . $latlong[0];
	}

This returns the latitude and longitude of the address passed to it, for example: 51.2343500, -0.7325510. You can also access this through the $latlong array.

Naturally, it’s had my details stripped out of it. You can get an API key here.

Microformats: Geo

Thu, 16 Jul 2009 21:05:01 +0100

This is the first in a series of posts which will provide examples of the various Microformats. “Geo” is used to markup Latitude and Longitude data into web pages, rather useful for providing location data near/around maps.

    
        N 37° 24.491 
        W 122° 08.313

Source: Microformats Wiki: Geo

Gravatars as User icons in PHP

Thu, 16 Jul 2009 17:26:00 +0100

This is an extension of the Gravatar docs, which seemed to be a little lackluster in the PHP department.

	$email = "nickcharlton91@gmail.com";
	$size = "80";
	$gravatar =  "http://www.gravatar.com/avatar/" . md5($email) . "?s={$size}";

        " alt="Gravatar" width="" height="" />

I’m sure there are similar ways to do this, some most likely more flexible, but this is a great way to slot in user icons in projects. I especially like Github’s way of not making you upload a photo. (Obviously, it’s biggest use is in Blogs, but I digress.)

Strip Tags & Protect Against Injection Attacks

Tue, 14 Jul 2009 15:01:50 +0100

Whilst this is not a perfect way to protect against attacks, it is a step.

function clean_input($input) {
	// note, needs a MySQL connection
	$clean = strip_tags($input);
	$cleaner = mysql_real_escape_string($clean);
	
	return $cleaner;
}

Best used wrapped around a string. e.g. clean_input($string);

Validate an Email Address using Regex

Fri, 03 Jul 2009 18:52:46 +0100

This function validates an email address passed to it and returns either True or False.

function validate_email($email) {
	$match = "/^[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z_+])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,9}$/";
	$regex = preg_match($match, $email);
	
	return $regex;
}

Header Redirect

Wed, 01 Jul 2009 14:57:32 +0100

This simple snippet redirects from one page to another. Note: Must be sent before the rest of the content.

    header('Location: login.php');
    exit();

An Improved Linux Uptime Function

Mon, 22 Jun 2009 01:35:00 +0100

This is an improvement over this post. This also produces an uptime, but properly splits the seconds in “days”, “hours”, “minutes” & “seconds”, as well as appending s or not if it should be there.

Could further be improved to include options to be called from the function.

function uptime() {
	$procuptime = popen("cat /proc/uptime | awk -F \" \" '{print $1}'", "r");
	$read = fread($procuptime, 2096);
	$day = floor($read / 86400);
	$hour = floor(($read % 86400) / 3600);
	$minute = floor((($read % 86400) % 3600) / 60);
	$second = floor(((($read % 86400) % 3600) % 60));
			
	if ($day == "1") {
		echo "$day day ";
	} else {
		echo "$day days ";
	}
	if ($hour == "1") {
		echo "$hour hour ";
	} else {
		echo "$hour hours ";
	}
	if ($minute == "1") {
		echo "$minute minute ";
	} else {
		echo "$minute minutes ";
	} 
	if ($second == "1") {
		echo "$second second ";
	} else {
		echo "$second seconds ";
	} 
}

Linux Free, Used & Total Memory

Thu, 04 Jun 2009 02:49:31 +0100

This shows free, used and total memory. This like the other one, is somewhat complex and uses a mix of shell commands and PHP.

// displays total and free memory
	// total memory
	$total = popen("/usr/bin/free | grep \"Mem:\" | awk -F\" \" '{print $2}'", "r");
	$read = fread($total, 2096);
	$totalram = round($read / 1000, 2);
	pclose($total);
	// used memory
	$used = popen("/usr/bin/free | grep \"Mem:\" | awk -F\" \" '{print $3}'", "r");
	$read = fread($used, 2096);
	$usedram = round($read / 1000, 2);
	pclose($used);
	// free memory
	$freeram = $totalram - $usedram;

Linux Used and Free Disk Space on a Volume

Thu, 04 Jun 2009 02:47:06 +0100

This somewhat complex bit of code shows the used and free disk space on a specified volume. Uses a mix of shell commands and PHP here.

// displays disk space for the "/dev/xvda1" volume
	// used space
	$used = popen("/bin/df -k | grep \"xvda1\" | awk -F\" \" '{print $3}'", "r");
	$read = fread($used, 2096);
	$systemused = round($read / 1000000, 2);
	pclose($used);
	// free space
	$free = popen("/bin/df -k | grep \"xvda1\" | awk -F\" \" '{print $2}'", "r");
	$read = fread($free, 2096);
	$systemcap = round($read / 1000000, 2);
	pclose($free);

Linux Kernel Version

Thu, 04 Jun 2009 02:44:41 +0100

Prints the current Kernel Version, eg “2.6.18-xenU”

function kernel() {
		$la = popen("uname -r", "r");
		$read = fread($la, 2096);
		echo $read;
	}

Debian Version Number

Thu, 04 Jun 2009 02:43:40 +0100

This shows the Debian version number, eg “4.0”.

function debianversion() {
		// naturally only works on Debian.
		$la = popen("cat /etc/debian_version", "r");
		$read = fread($la, 2096);
		echo $read;
	}

Linux Uptime

Thu, 04 Jun 2009 02:42:35 +0100

This prints the machines uptime, but only in days.

function uptime() {
		$la = popen("/usr/bin/uptime", "r");
		$read = fread($la, 2096);
		$value = substr($read, 13, 7);
		echo $value;
	}

Note: This should be improved to show a much more complex date/time. Not showing the time is, annoying.

Linux Load Average

Thu, 04 Jun 2009 02:40:00 +0100

This example prints the load average of the machine.

function loadaverage() {
		$la = popen("/usr/bin/uptime", "r");
		$read = fread($la, 2096);
		$value = substr($read, -17);
		echo $value;
	}

Printed like: “0.02, 0.01, 0.07”.

Convert kB to MB & kB to GB

Wed, 03 Jun 2009 22:38:00 +0100

The first example converts kB (kilobyte) to MB (megabyte) and the second from kB to GB (gigbyte) and rounds it to a nice 2 decimal places.

    round($read / 1000, 2)

    round($read / 1000000, 2)

Rewriting URL's with Strings

Thu, 28 May 2009 01:29:21 +0100

This example uses Apache’s mod_rewrite to convert a url like http://url/img.php?img=5 to http://url/5.

RewriteEngine On
RewriteRule ^([a-zA-Z0-9_-]+)$ img.php?img=$1
RewriteRule ^([a-zA-Z0-9_-]+)/$ img.php?img=$1

Calculate Directory Size

Thu, 28 May 2009 00:16:54 +0100

In this example, the size of a given directory is output. Note: This will only work on Linux.

$f = "./files";
$io = popen ("/usr/bin/du -sk " . $f, "r");
$size = fgets ($io, 4096);
$value = substr($size, 0, -8);
pclose ($io);
echo $value;

The directory name is held in $f, the “-8” value would need to be changed to remove the correct number of characters, or replaced with another function which would calculate the length of $f. Not used here to keep it simple.

pushimage: A Function to Dynamically Output Images

Wed, 27 May 2009 21:07:00 +0100

This example provides a function which when passed a variable, will output the file of that variable. This makes the assumption that the file is located in “files/thenameofthefile.ext”.

function pushimage($file) {
	$file = "files/" . $file;
	if (file_exists($file)) {
		header('Content-Type: image/jpeg');
		header('Expires: 0');
		header('Content-Length: ' . filesize($file));
		ob_clean();
		flush();
		readfile($file);
		exit;
	}
}

Note: At the time of posting, this does not check to ensure the file extension being returned is correct.