price_monitoring_bot.php

<?php

include("lib/http.php");
include("lib/parse.php");

$product_array = array();
$product_count = 0;

# Download the target web page
$target = "http://www.webbotsspidersscreenscrapers.com/buyair/";
$ref = "";
$web_page = http_get($target, $ref);

# Parse html tables to an array
$tables = parse_array($web_page['FILE'], "<table", "</table>");

# Find the table containing products for sale
for ($i = 0; $i < count($tables); $i++) {
  if (stristr($tables[$i], "Products For Sale")) {
    
    # Parse the table rows to an array
    $table_rows = parse_array($tables[$i], "<tr", "</tr>");
    
    # Find the row containing the table header
    for ($row = 0; $row < count($table_rows); $row++) {
      if (stristr($table_rows[$row], "Condition")) {
        
        # Parse the cells in the header row to an array
        $table_cells = parse_array($table_rows[$row], "<td", "</td>");
        
        # Find the column numbers for each data type
        for ($col = 0; $col < count($table_cells); $col++) {
          $cell = strip_tags(trim($table_cells[$col]));
          if (stristr($cell, "ID#")) $id_column = $col;
          if (stristr($cell, "Product name")) $name_column = $col;
          if (stristr($cell, "Price")) $price_column = $col;
        }

        # Store the header row
        $header_row = $row;
      }

      # Find the last row 
      if (stristr($table_rows[$row], "Calculate")) break;

      # Parse product and price data
      if (isset($header_row) && ($header_row < $row)) {
        $table_cells = parse_array($table_rows[$row], "<td", "</td>");
        $product_array[$product_count]['ID'] = strip_tags(trim($table_cells[$id_column]));
        $product_array[$product_count]['NAME'] = strip_tags(trim($table_cells[$name_column]));
        $product_array[$product_count]['PRICE'] = strip_tags(trim($table_cells[$price_column]));
        $product_count++;
      }
    }
  }
}

# Display the collected data
for ($i = 0; $i < count($product_array); $i++) {
  echo "$i. ";
  echo "ID: ".$product_array[$i]['ID'].", ";
  echo "NAME: ".$product_array[$i]['NAME'].", ";
  echo "PRICE: ".$product_array[$i]['PRICE']."\n";
}

?>