ASIN Number Extracting Example

<?php
    $cur_file_path = realpath(dirname(__FILE__));

    // Set File Names
    // Just place the input file in the same directory as this script
    $input_file = $cur_file_path . "/list_of_input_urls.txt";
    $output_file = $cur_file_path . "/list_of_output_urls.txt";


/**
    Unless you know what you're doing I wouldn't change anything below
**/
    $aBigAssArray = array();
    $pattern = "/\/product\/([aA-zZ 0-9]*)\//";

    // Check if input file exists
if ( file_exists($input_file) ) {
    $input_handle = fopen($input_file, "r");
    $output_handle = fopen($output_file, "w");

    if ($input_handle) {
        while (($line = fgets($input_handle)) !== false) {
            preg_match($pattern, $line, $aResults);
            if ($aResults) {
                $asin = $aResults[1];
                if ( $asin ) {

/** Uncomment if you wanted to store all values in an array. */
//                     array_push($aBigAssArray, $asin);

                    fwrite($output_handle, $asin . "\n");

/** Uncomment to view lines as they're being processed */
// echo $asin . "</br>";
                }
            }
        }
        fclose($input_handle);
    } else {
        // Error - Could not open file
    }


/** Uncomment if you wanted to view each line stored in the array. */
//     foreach ($aBigAssArray as $asin_line):
//         echo $asin_line . "</br>";
//     endforeach;

    die('<hr>End Of Script');
}