//Many thanks to Tom Igo, much of this is adapted from his code :)

<?php

/*

AIRNow Web Page Scraper

Language: PHP

*/

// Define variables:
$readParticles = 0; // flag telling you the next line
// is the particle value
$particles = -1; // the particles value

// url of the page with the air quality index data for New York City:

$url =

'http://thomas-gerhardt.com/itp/2007/10/08/flag-waver/';

// open the file at the URL for reading:

$filePath = fopen ($url, "r");

// as long as you haven't reached the end of the file:

while (!feof($filePath))

{

// read one line at a time, and strip all HTML and

// PHP tags from the line:

$line = fgetss($filePath, 4096);

// if the current line contains the substring "AQI observed at"
// then the line following it is either the particle reading
// or the ozone reading:
if (preg_match('/so far/', $line)) {
// if $particles == -1, you haven't gotten
// a value for it yet:
if ($particles == -1) {
$readParticles = 1;
}

// if the previous line was the "observed at line" preceding
// the particle matter reading, then $readParticles = 1 and
// you should get this line, trim everything but the number,
// and save the result in $particles:
if ($readParticles == 1) {
$particles = trim($line);
echo "<$particles>";
$readParticles = 0;
}

}

}

// close the file at the URL, you're done:

fclose($filePath);

?>