Posts tagged Code
PHP Weirdness
Aug 14th
Beware: this post is definitely not for the feint of heart. It includes a lot of code. You have been warned.
I wrote an application some time ago for my company that looks up the longitude and latitude of an address for use in our geocoding initiative. It relied on yahoo_geo(), a function written by PHP creator Rasmus Lerdorf and the Yahoo Maps API. It was largely dependent on this function:
function yahoo_geo($location) { $q = 'http://api.local.yahoo.com/MapsService/V1/geocode?appid=rlerdorf&location=' .rawurlencode($location); $tmp = '/tmp/yws_geo_'.md5($q); request_cache($q, $tmp, 43200); libxml_use_internal_errors(true); $xml = simplexml_load_file($tmp); $ret['precision'] = (string)$xml->Result['precision']; foreach($xml->Result->children() as $key=>$val) { if(strlen($val)) $ret[(string)$key] = (string)$val; } return $ret; }
This function worked for over two years for us with no problems at all. Then suddenly, in the last month, it started getting spotty. I fixed things by commenting out the caching parts of the function and forcing each execution to run again. Then I got errors about the libxml_use_internal_errors() function, so I commented that out. But today, the function just flat out failed, every single time returning the same error:
Warning: file_get_contents(http://XXXXXXXXXX/XXX) [function.file-get-contents]: failed to open stream: HTTP request failed! in /home/intranet/html/fetch.php on line X
What the heck? This code is all over the web. I’ve tried a million permutations of this function, including using fopen() and ob_get_contents(), and none have worked. And most frustratingly, I could load the URL successfully in Lynx and eLinks, so the machine could quickly and easily fetch the URL.
So I ventured into a sandbox I’ve never really played before: cURL. cURL is an interesting animal. But the interesting thing is, once I got it working, it worked faster than ever! So, without further ado, here is the new and improved yahoo_geo() function:
function yahoo_geo($location) { $q = 'http://api.local.yahoo.com/MapsService/V1/geocode?appid=rlerdorf&location='.urlencode(trim($location)); $ch = curl_init($q); curl_setopt($ch, CURLOPT_HEADER, 0); ob_start(); curl_exec($ch); $stream = ob_get_contents(); ob_end_clean(); if($stream) { $xml = simplexml_load_string($stream); $ret['precision'] = (string)$xml->Result['precision']; if($xml) { foreach($xml->Result->children() as $key=>$val) { if(strlen($val)) $ret[(string)$key] = (string)$val; } } curl_close($ch); return $ret; } else { return FALSE; } }
Note: If you’re reproducing these functions elsewhere, be careful – WordPress may have converted the quotes into smart quotes that will need to be fixed before this script will run properly.
OSNews vs. WordPress
Aug 13th
I’ve spent quite a bit of time, over the last 5 or 6 days, diving into WordPress and learning what makes it tick. Parts of WordPress are really impressive – just flat out cool. The way some of it works is fairly complex and deciphering it sometimes means reading page after page after page to understand an entire routine. But sometimes, when you finally see, end to end, how something in WordPress works – I mean really see individual bits of the engine – you have to admit it teaches you a little about PHP. WordPress, underneath it all, is a pretty big beast and its strength and ubiquitous presence comes largely, I think, from the fact that it can do virtually anything. The really sweet plugin system, the ways hooks work, “The Loop,” the dynamic options panel – it’s all very educational.
The interesting thing here is that I’ve browsed the source of Slash, Scoop, phpNuke, and now WordPress, and all of them are definitively more complex and much heavier than the entire OSNews codebase. Now, before you jump all over me – firstly, Slash and Scoop are Perl, and I don’t really read Perl, so I can’t speak as an expert there. Secondly, WordPress and Nuke both are very portable and dynamic, whereas OSNews has a narrow focus and, location-wise, is very static. But that aside, OSNews has withstood simultaneous link bombs from Slashdot and Digg. As amazing as WordPress is, it’s mostly amazing that it functions at all and loads in less than 2 minutes per page with as much going on as I can see behind the scenes. That’s not a cut on WordPress, by the way.
In fact, if anything , what is really impressed upon me is how smooth and simple OSNews code is, if I may be so bold. OSNews runs superfast due, in part, to lots of creative caching, some on-demand, some via cron. But it also does so because of highly efficient queries that are measured for speed on their JOINs, meaning in some cases, it’s faster to do 20 simple queries than one complex one, or build a long and scary chain of “OR x=a OR x=b OR x=c OR x=d…” Watching WordPress code in action is really fun for me, but watching OSNews work knowing what I now know about how much work PHP can cram into its threads is even more fun.
Dope Wars for the iPhone
Apr 30th
I love my jailbroken iPhone, and I am always looking for a new “game of the week.” I’ve been through several, at first, it was LightsOff, but that ends at 225 levels or so. Then it was Five Dice. Then 4 Balls, Domino, and finally PuzzleManiak. I was so happy recently when someone decided to port Dope Wars to the iPhone in the form of “iDope.”
iDope currently has a lot of bugs. Mainly, your jacket storage is irrelevant, you can actually store unlimited items, you just can’t buy unlimited items unless you hit “buy all.” You can’t store money in a bank. It never ends until you die. You are mugged or fight the cops maybe 80% of the time you travel. But most importantly, this:
Notice my dollars? That’s right, I have $2,147,483,647. Two billion, one hundred forty seven million, four hundred eighty three thousand, six hundred forty seven dollars. Recognize that number? If you read my blog regularly, you might. After all, it’s the upper limit of signed integers. The game is officially boring – no matter what I do, I’m always capped at that number, I can never get more money. I wonder if the iPhone can support BIGINT.
Anyway, I really hope to see iDope get some love and attention, because Dope Wars is a fabulous and addictive game, but as is, I eventually get to the upper limit and have to start over… and over… and over.
How To REALLY Survive Digg on a Shared Host
Jan 2nd
After reading a ridiculous post on “surviving the Digg effect on a shared host,” (and then laughing ridiculously at it), I decided to write a real tutorial on real-live ways not only to survive the Digg effect, but also a simple but powerful way to improve your site’s performance. Read more within.
Integers on the Intertubes
Dec 12th
Some time ago, I wrote an application for my company. Like most weblets I’ve written, this used PHP and either MySQL or MSSQL for the backend. This particular application logged all phone calls. As part of the record, it would record the caller’s account number, which is a 5 or 6 digit integer.
So, I got a phone call from the director of our customer contact department this week. He was concerned about the reports. He made a decision last week that when a call came in that was a lead – in other words, a non-customer, that his people would fill the phone number from the caller ID into the account number field. But when he ran his export reports, he found that hisn techs had entered this phone number for ALL of the calls: 429-496-7295. That’s weird, he said. So he called me and asked why that was. I checked all the calls and most were from one woman, so my first instinct was “Check if her browser has autocomplete turned on”. But he swore that he tried it too and gotten the same result.
I checked the database and sure enough, it was right there: 429-496-7295, in all of the fields. So I went back to the code. In short, I took the input from the form, and declared it like this:
$accountnum = (int) $_POST['accountnum'];
Pretty straightforward: explicitly declare the type. So, I started my debugging by attempting to manually enter the data into the database. Sure enough: the account key field showed this: 4294967295.
So, I went back to the PHP and started by dumping out the raw SQL query:
INSERT INTO calls ('','x','x','x','4294967295','x','x');
What? So the database automatically converts it to this weird phone number and PHP does too? Suddenly it occured to me. One of the benefits of 64-bit computing is the ability to address more memory. There are limits to what can be done in 32-bit computing, and one is that integers have a limit! In this case, a database field called “integer” is limited to numbers between -2,147,483,648 and +2,147,483,647. It just so happens that the number is the same length as a US phone number – 10 digits. Changing the db field to “BIGINT” allowed me to manually run the SQL query and it worked. But the app still didn’t.
PHP’s int() and (int) $var syntaxes both conform to the integer limit. So I devised a work around:
$ac = $_POST['accountnum']; if(!is_numeric($ac) { $ac = (int) $ac; }
It’s not gorgeous, but it will more than suffice for an internal app. We web programmers don’t usually have to deal with big integers, so it’s totally possible that web developers would never have had occasion to handle a situation like this. Here’s looking forward to native 64-bit for our next server, though.
Meta: New Feature
Jul 14th
I’ve added a little detection script to the comments that records your user agent and tries to put nice little icons next to your name. The icons should depict your browser and operating system. Hovering over the browser icon will show the entire user agent. This detection script is at a very early stage, so I’m still reviewing user agents to best make it work, and only a few comments on the site even have the info properly stored thus far. If you want to test it, please use this thread.
PHP vs. ASP.NET
Apr 27th
We have a new web-based client portal application we are going to use for my company extranet. However, because it was originally designed to be a hosted application, there are several variables involved in all areas that don’t apply to us, since we host it ourselves.
When using said portal, every URL looks something like:
domain.com/login.aspx?QS=jasbndfiaubnfoaeuifwoeifbwfe
The only difference is that the “QS” GET variable is even longer. I made the request of our developers to get rid of this query string for the login page, and the login page only. This is what that code looks like in PHP, inserted at line 1.
if(!$_GET['QS']) { $_GET['QS'] = 'jasbndfiaubnfoaeuifwoeifbwfe'; }
That’s it. One line of code. In ASP.net, this cost me 3 hours of developer time. THREE hours.
Then I asked our old developers to make a change to their code. It was doing a check in login if they are customers from the new app or the old one. If they are old, it processes the login. If it’they are new, it gives them an error message. So I said, instead of giving them the error, let’s redirect them to /new-directory/login.aspx?email=[base64_encoded email]&password=[base64_encoded password].
This is that code in PHP:
if($is_new) { header("Location: /newdirectory/login.aspx?email=" .base64_encode(stripslashes($_POST['email'])) . "&password=" .base64_encode(stripslashes($_POST['password']))); } else { //process login }
This cost me 2 hours at $165. Am I getting taken for a ride? I keep telling them – this would take 30 seconds in PHP. And they tell me, yes but ASP.net doesn’t work that way, and we need to change the web.config, and we need to recompile the entire site, etc, etc. If it were just one vendor, I’d be more suspicious, but two separate, unrelated developers are giving me crazy quotes like this.
I hear people bitch about PHP online ad nauseum. Every time I see real code, it appears PHP is FAR faster and far more friendly when it comes to customization.