http://qs321.pair.com?node_id=131685
Category: Web Stuff
Author/Contact Info cacharbe Chuck Charbeneau ccharbeneau@lear.com
Description: A while back I had to re-write our intranet stock listing application that retreived stock information from the Yahoo! finance site (I didn't write the original). It was a huge cluge, and took forever to render, as each stock symbol, 401k symbol etc, was a seperate LWP request, and each request had to be parsed for the necessary data. The application began breaking down when Yahoo went through some major HTML/Display rewrites.

While working on the re-write I discovered something that turned 75 LWP requests into two requests; one for the indices information, and one for the list of symbols for which I needed data. The discovery was that Yahoo has a publically facing application server that offers up all financial data in CSV rather than html. I could request ALL the symbols I needed at once, and it was returned in orderly, well formatted, easy to parse CSV.

Needless to say, I saw a significant performance increase.

Yesterday I was asked if I could create a small web application that allowed users to get current currency exchange rates, and rather than re-inventing the wheel, I went back to the stock work I had done and found that the same server would do the exchange for you if given the correct URL. I have included an example of a correct URL, but I am leaving getting the correct Country Currency codes as an exercise to the user. They are readily available from a few different sources.

Usage might be somethig like:

use LWP::Simple;
use LWP::UserAgent;
use CGI;

$|++;
print "Content-type: text/html\n\n";
&Header();
&PrintForm();
my $q = new CGI;
if ($q->param("s") && $q->param("s") ne "DUH" && $q->param("t")ne "DUH
+"){ 
    my $sym = $q->param("s").$q->param("t")."=X";
    my ($factor, $date, $time) =  (&GetFactor($sym))[2,3,4];
    $time =~ s/"//g;
    $date =~ s/"//g;
    print '<CENTER><p><b><font face="Arial" size="4">RESULTS:</font></
+b> ';
    printf("<b><font face=\"Arial\" color=\"#0000FF\" size=\"4\">%s %s
+ = %s %s as of %s, %s </font></b></p>",&commify($q->param("a")), $q->
+param("s"), &commify(($factor*$q->param("a"))), $q->param("t"),$date,
+$time);
    print "</CENTER><P>";
}

&PrintFoot(\$q);

[download]

C-.

 
sub GetFactor {
 
    my ($symbol) = @_; #Expects either ^Xyy where yy = 2 letter code o
+r AAABBB=X
                       #WHERE A and B are Official three letter Countr
+y Codes, AAA
                       # being the 'From' money, and BBB
                       #being the 'To' money ex. Us dollar to British 
+Pound would be 
                       #USDGBP=X
    my $src_url = "http://finance.yahoo.com/d/quotes.csv?f=snl1d1t1c1o
+hgv&e=.csv&s=".$symbol;
    $ua = new LWP::UserAgent;
    $ua->proxy(http => 'http://<PROXY INFO>');
    $ua->agent('Mozilla/2.0 (compatible; MSIE 3.02; Win32)');
    $ua->timeout(30);

    $req = new HTTP::Request GET => $src_url;
    $req->proxy_authorization_basic('<USERNAME>', '<PWD>');
    $resp = $ua->request($req);

    if (!$resp->is_success || !$resp) {
        $errmsg = "<FONT COLOR=#FF0000>Failed to retrieve stock indice
+s --". $resp->Status_line ." $!</FONT>";
        print "$errmsg<br>\n";
        die;
    }
    #$resp->Format = <SYMBOL>,"<SOURCE>",<FACTOR>,"<LAST TRADE DATE>",
+"<LAST TRADE TIME>",N/A,N/A,N/A,N/A,N/A
    return split /,/,$resp->content;
}

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