Yahoo! Finance is a very useful resource for both analysts and programmers alike. A PHP library is created by saving the function into a text file - in this example the library is going to be called yahoo_finance.php and this will contain a single function: [php] <?php function show_stock_quotes ($stock_list) { //The function will, by default, return the details of some of the stock markets: if (! $stock_list) { $stock_list = "^IXIC,^DJA,^NIN,^FTSE"; } //The function will then use either an input list or the default list to create the correct url: $url = "http://quote.yahoo.com/d/quotes.csv?s=". $stock_list . "&f=nl1c1&e=.csv"; //and then read in the data stream from the Yahoo! Finance web site: $filesize = 2000; $handle = fopen($url, "r"); $raw_quote_data = fread($handle, $filesize); fclose($handle); //The data will be in the format: "BSE-100",4.37,0.47…